CN111441306A - Hydrodynamic force improving method and performance testing method thereof - Google Patents

Abstract

The invention discloses a hydrodynamic lifting method, which comprises the steps of S1, if the hydrodynamic lifting requirement is to improve the hydrodynamic force of the edge part of a hydrodynamic weak area, arranging a plurality of water pump jet flow impellers at intervals on the edge part of the hydrodynamic weak area; s2, if the hydrodynamic lifting requirement is to improve the hydrodynamic force of the central part of the hydrodynamic weak area, placing a vertical shaft flow impeller in the center of the hydrodynamic weak area; and S3, if the hydrodynamic lifting requirement is that the device has both the entertainment function and the hydrodynamic lifting function, placing a suspension wave generator in the center of the hydrodynamic weak area. The invention also discloses two performance test methods of the method, one is to adopt a physical reduction model, and the other is to adopt mathematical modeling to carry out numerical simulation. The hydrodynamic force lifting method can realize multi-purpose hydrodynamic force lifting, the adopted testing method accurately quantifies the improvement effect of the hydrodynamic force weak area after the method is operated, and decision basis is provided for scientifically and economically operating the hydrodynamic force device and improving the hydrodynamic force condition of the river channel.

Description

Hydrodynamic force improving method and performance testing method thereof

Technical Field

The invention relates to a water conservancy technology, in particular to a hydrodynamic force lifting method and a performance testing method thereof.

Background

Does not decay in running water and is a moth-proof house. In recent years, the natural hydrological conditions of a plurality of rivers are artificially changed, so that the dynamic conditions of the river water flow are remarkably changed; especially, the construction of excessive gate dams is favorable for improving the utilization efficiency of water resources, but easily causes the hydrodynamic conditions of local areas of the river channel to be greatly weakened, has poor water exchange capacity, and is not favorable for the migration and diffusion of pollutants flowing into the river channel, thereby aggravating the pollution of the water and influencing the production and life of people. In order to meet the requirements of people on living environment, the hydrodynamic force condition of the riverway is improved, the flow velocity of the riverway can be increased, the flowing effect of water flow is created, the reoxygenation capacity of the water body can be improved, the degradation of pollutants is accelerated, and therefore the purpose of improving the water quality is achieved.

In the prior art, most of the methods adopt a water adjusting and drainage mode to control and improve the hydrodynamic condition of the riverway, and an independent or series submersible pump is occasionally used for improving the hydrodynamic condition, but the effect is limited.

In addition, to local weak power region, because hydrodynamic force hoisting device's operation effect often receives multiple factor restrictions such as power size, river course water level, working costs, how to realize hydrodynamic force under the different situation and promote the purpose, how to quantitatively evaluate hydrodynamic force promotion scheme operation back hydrodynamic force weak area's improvement effect, is the difficult point that present hydrodynamic force promotion technical application field is urgent to be solved.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides a hydrodynamic force lifting method and two performance test methods thereof.

The technical scheme is as follows: the hydrodynamic lifting method comprises the following steps:

s1, if the hydrodynamic force lifting demand is to improve the hydrodynamic force of the edge part of the hydrodynamic force weak area, placing a plurality of water pump jet flow impellers at intervals on the edge part of the hydrodynamic force weak area, wherein each water pump jet flow impeller comprises a bottom plate, a water stop sheet, a plurality of buoys and a plurality of water pumps, the buoys are arranged on two sides of the bottom plate and connected with a plurality of anchors through anchor ropes, the water pumps are arranged on the bottom plate side by side, a water inlet pipe is connected to a water inlet of each water pump, the length of each water inlet pipe is sequentially increased from the middle position to two sides, a water outlet of each water pump is connected with a water outlet pipe, the lengths of all the water outlet pipes are consistent, the water stop sheet is vertically fixed on the bottom;

s2, if the hydrodynamic lifting demand is to improve the hydrodynamic force of the central part of the hydrodynamic weak area, placing a vertical shaft flow impeller in the center of the hydrodynamic weak area, wherein the vertical shaft flow impeller comprises a support, a motor, a flow pushing plate and a vertical shaft, the motor is fixed on the support, the motor is connected with one end of the vertical shaft, the other end of the vertical shaft is fixed with the flow pushing plate, the flow pushing plate is rectangular, and the length of the flow pushing plate is 1/15-1/3 of the maximum radius of the hydrodynamic weak area;

s3, if hydrodynamic force promotes the demand and for having entertainment function and hydrodynamic force lifting function concurrently, then place the suspension in the weak regional center of hydrodynamic force and make unrestrained ware, the suspension is made unrestrained the ware and is included motor, bent axle, float support, connecting wire, pulley and flotation pontoon, the motor with the pulley mounting is in float on the support, the bent axle is fixed on the motor, connecting wire one end is connected the bent axle, the other end is walked around the pulley and is located the flotation pontoon under the support and be connected.

Further, the length of a flow pushing plate of the vertical shaft flow pusher is preferably 1/10-1/5 of the maximum radius of a hydrodynamic weak area; the water pump jet flow impeller is provided with four anchors which are respectively arranged at four corners of the bottom of the outer side of the floating barrel. And the vertical shaft of the vertical shaft flow impeller is fixed on the central line of the flow impeller.

The performance test method of the hydrodynamic force lifting method comprises the following steps:

the performance of the water pump jet flow impeller in the step S1 is tested according to the following method:

s11, acquiring a hydrodynamic weak area and the size of the corresponding water pump jet flow impeller;

s12, establishing a physical model of the hydrodynamic weak area and the water pump jet flow impeller after reduction, wherein the reduction scale is a preset plane scale lambda_L；

S13, acquiring a central point of the physical model of the hydrodynamic weak area, and placing the physical models of the water pump jet flow impeller on a circumference close to a bank by taking the central point as a circular point, wherein the direction of a water outlet pipeline of the water pump jet flow impeller is the tangential direction of the circumference; taking the circle center as a starting point, arranging s1 radial equally-spaced flow velocity measuring points, and arranging s2 tangential equally-spaced section flow velocity measuring points on the circumference of each flow velocity measuring point;

s14, setting n1 working conditions, specifically setting the water pump capacity of the water pump jet flow impeller to E₁,E₂,…,E_n1And according to the energy scale lambda_EConverting the set working condition to obtain the water pump capacity E of the physical model of the water pump jet flow impeller₁’,E₂’,…,E_n1' according toE₁’,E₂’,…,E_n1' get the number of water pumps needed to be turned on, where,

i1＝1,…,n1；

s15, starting the water pumps with the corresponding number according to the set working conditions to obtain a flow rate set V1 ' ═ V ' of all flow rate measuring points under all the working conditions '_j1|j1＝1,…,s1*s2}；

S16, all the flow rates in the flow rate set V1' are adjusted according to the flow rate scale lambda_vThe conversion is carried out to obtain that the flow velocity set in the natural state of the hydrodynamic weak area is V1 ═ V_j11, …, s1 s2}, wherein v is j1 ═ 1, …, s 3526 ═ s2}, in which v is a linear chain structure_j1＝λ_vv'_j1，

S17, obtaining the performance of the water pump jet flow impeller according to the flow rate set as V1, wherein the larger the flow rate of a weak power area is, the better the hydrodynamic force lifting performance is;

the performance test of the vertical shaft flow pusher in the step S2 is carried out according to the following method:

s21, acquiring the hydrodynamic weak area and the size of the corresponding vertical shaft impeller;

s22, establishing a physical model of the hydrodynamic weak area and the reduced vertical shaft impeller, wherein the reduction scale is a preset plane scale lambda_L；

S23, placing the physical model of the vertical shaft impeller in the center of the physical model of the hydrodynamic weak area, and setting S3 flow rate monitoring devices at radial intervals by taking the center point of a thrust plate of the physical model of the vertical shaft impeller as a starting point;

s24, setting n2 working conditions, specifically setting the rotating speed of the motor of the vertical shaft impeller to w₁、w₂、…、w_n2And according to the rotation speed scale lambda_wConverting the set rotating speed to obtain the rotating speed w of the motor in the physical model of the vertical shaft impeller₁’、w₂’、…、w_n2', wherein,

i2＝1,…,n2；

s25, according to the rotating speed w₁’、w₂’、…、w_n2'starting a motor to drive the flow pushing plate to rotate, and obtaining a flow rate set V2' ═ V 'monitored by the flow rate monitoring device at all rotating speeds'_i2j2L i2 ═ 1, …, n2, j2 ═ 1, …, s3}, where v'_i2j2Denotes a rotational speed w'_i2The flow rate monitored by the flow rate monitoring device j 2;

s26, all the flow rates in the flow rate set V2' are adjusted according to the flow rate scale lambda_vThe conversion is carried out to obtain that the flow velocity set in the natural state of the hydrodynamic weak area is V2 ═ V_i2j21, …, n2, j2, 1, …, s3, wherein v is2 | i_i2j2＝λ_vv’_i2j2，

S27, obtaining the performance of the vertical shaft impeller according to the flow velocity set V2, wherein the larger the flow velocity of the weak power area is, the better the hydrodynamic force lifting performance is;

the performance test is carried out on the suspended wave maker in the step S3 according to the following method:

s31, acquiring the size of the hydrodynamic weak area;

s32, establishing a physical model after the hydrodynamic weak area is reduced, wherein the reduction scale is a preset plane scale lambda_L；

S33, randomly selecting S4 monitoring points in the hydrodynamic weak area physical model to arrange wave height monitoring equipment;

s34, setting m x n3 working conditions, specifically setting the diameter or side length of a float bowl in the suspension wave making device as r₁、r₂、…、r_mThe amplitude of the float is h₁、h₂、…、h_n3According to the plane scale lambda_LConverting the set working conditions to obtain m × n3 working conditions of the physical model of the suspended wave generator, specifically the diameter or the side length r₁’、r₂’、…、r_n3' float amplitude divisionIs otherwise h₁’、h₂’、…、h_n3The method of' wherein, in the step of,

i3＝1,..,m，j3＝1,…,n3；

s35, starting the motor according to preset working conditions to obtain a wave height set A ' ═ a ' under all working conditions '_lL-m-n 3 s4 and wave period set T '{ T'_l|l＝m*n3*s4}；

S36, all the wave amplitudes in the wave height set A' are adjusted according to the plane scale lambda_LConverting all wave periods in the wave period set T' according to a period scale lambda_TConverting to obtain a wave amplitude set A ═ a in a natural state in the hydrodynamic weak region_lL-m-n 3 s4 and wave period set T-T_lI | m ═ n3 | s4}, wherein a is_l＝λ_La’_l，t_l＝λ_Tt’_l，

And S37, obtaining the performance of the suspended wave maker according to the wave height set A and the wave period set T, wherein the higher the wave height in the weak power area is, the better the hydrodynamic force lifting performance is.

The performance test method of the other hydrodynamic force lifting method comprises the following steps of:

s41, establishing a hydrodynamic mathematical model of the hydrodynamic weak area, which specifically comprises the following steps:

(1) mass continuity equation:

wherein u, v, w are the velocity components in three directions of a Cartesian coordinate system x, y and z, A_x,A_y,A_zIs the fractional area of the flow in the x, y, z directions, respectively, ρ is the fluid density, R_SORIs a density source item;

(2) the momentum equation:

in the formula, G_x,G_y,G_zThe gravity acceleration in the x direction, the y direction and the z direction respectively; f. of_x,f_y,f_zThe viscous force acceleration in the x direction, the y direction and the z direction respectively; item U_w＝(u_w，v_w，w_w) Representing the velocity of the source assembly in three directions; item U_s＝(u_s，v_s，w_s) Representing the velocity of the fluid at the source surface in three directions relative to the source itself; v_FThe fluid volume fraction with a free surface, R is a coordinate coefficient, when a Cartesian coordinate system is selected, the value is1, a coefficient is represented, when 0 is taken, the pressure boundary condition is a stagnation type, and when 1 is taken, the pressure boundary condition is a static pressure type;

(3) a turbulence model:

in the formula, k_TIs kinetic energy of turbulence, P_TFor the turbulence-generating term, G_TIn order to generate the term for the buoyancy,

is a diffusion term，_TFor turbulence energy dissipation ratio, RMTKE, CDIS1 and CNU are user-defined parameters with default values of 1.39, 1.42 and 0.085, respectively, CDIS2 is defined by k_TAnd P_TIs calculated to obtain v_TIs a kinematic turbulent viscosity;

(4) fluid distribution:

the fluid distribution is defined in terms of a fluid volume function F (x, y, z, t) that represents the volume of fluid #1 per unit volume and satisfies the following equation:

in the formula: f is an abbreviation for the function F (x, y, z, t), ζ is the coordinate coefficient whose value is 0, ν when a Cartesian coordinate system is used_FAs diffusion coefficient, F_SORIs the density source term, is the volume fraction time rate of change of fluid #1 associated with the mass source;

s42, obtaining the boundary of the hydrodynamic weak area, dividing the boundary into a plurality of grids by adopting a hexahedral structured grid, setting the periphery and the bottom of the hydrodynamic weak area to be non-displacement Wall boundaries, setting the top to be a pressure boundary, setting the atmospheric pressure to be 1.01 × 105Pa, and setting the fluid fraction to be 0, wherein the boundary represents that the hydrodynamic weak area is completely air;

s43, establishing a mathematical model of the water pump jet flow impeller, obtaining a central point of the hydrodynamic weak area, placing the water pump jet flow impellers on a circumference of the hydrodynamic weak area close to the bank by taking the central point as a circular point, and taking the direction of a water outlet pipeline of the water pump jet flow impeller as the tangential direction of the circumference; setting n1 working conditions, specifically setting the water pump capacity of the water pump jet flow impeller to E respectively₁,E₂,…,E_n1；

S44, establishing a mathematical model of the vertical shaft impeller, and placing the mathematical model in the center of the hydrodynamic weak area; and setting n2 working conditions, specifically setting the rotating speed of the flow pushing plate of the hydrodynamic lifting device to w₁、w₂、…、w_n2；

S45, establishing a mathematical model of the suspended wave making device, and placing the mathematical model in the center of the hydrodynamic weak area; and setting m x n3 working conditions, specifically setting the diameter or side length of the buoy of the hydrodynamic lifting device as r₁、r₂、…、r_mThe amplitude of the float is h₁、h₂、…、h_n3The working condition of (1);

s46, starting according to set working conditions respectively, tracking free surface flow through the established hydrodynamic mathematical model, determining the position of a free liquid level, and performing discrete solution and GMRES implicit solver calculation on the model based on a finite difference method to obtain velocity distribution of each region under all the working conditions;

and S47, obtaining the performance of the hydrodynamic lifting device according to the speed distribution of each region under each working condition, wherein the larger the flow speed is, the better the hydrodynamic lifting performance is.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: aiming at different requirements, different devices are adopted for hydrodynamic lifting, hydrodynamic lifting effects of different requirements can be met, two performance test methods are further provided, the overall and local effects of the hydrodynamic lifting device are quantitatively analyzed and predicted through a physical model and a mathematical model, and the final result also shows that the hydrodynamic lifting method improves hydrodynamic conditions of a weak power area, enhances water flow exchange capacity of the area, and provides decision basis for scientifically and economically operating the hydrodynamic lifting device, optimizing a hydrodynamic lifting scheme and improving river hydrodynamic conditions.

Drawings

FIG. 1 is a map of a Meishan water course and a wan-men beach weak dynamic area;

FIG. 2 is a schematic structural view of a water pump jet impeller provided by the present invention;

FIG. 3 is a side view of FIG. 2;

FIG. 4 is a schematic structural view of a vertical axis flow impeller provided by the present invention;

fig. 5 is a schematic structural diagram of the suspended wave maker provided by the present invention;

FIG. 6 is a schematic diagram of a physical model of a Meishan water channel and a Wanren beach weak dynamic area;

FIG. 7 is a schematic plan view of a water pump jet impeller;

fig. 8 is a schematic view of the positions of monitoring points of the suspended wave maker;

FIG. 9 is a position schematic of a mathematical model of a water pump jet ejector;

FIG. 10 is the overall flow velocity distribution of a hydrodynamic weak area when a water pump jet impeller is used under different working conditions (a: working condition 1, b: working condition 2, c: working condition 3);

FIG. 11 is a flow velocity profile near (partially enlarged area) a vertical axis flow pusher when the vertical axis flow pusher is employed;

FIG. 12 is a graph of the overall flow velocity distribution in a region of hydrodynamic weakness when a vertical axis impeller is used;

figure 13 is a flow velocity distribution near (a partially enlarged region of) a suspended wave generator when the suspended wave generator is employed;

fig. 14 is a flow velocity component of the entire hydrodynamic weak area when the floating wave generator is used.

Detailed Description

In the embodiment, the Meishan watercourse Wanren beach is used as a research object of a hydrodynamic weak area, the Meishan watercourse is positioned at the northwest side of the Meishan island in the northern Rankine district of Ningbo city, the south-north length of the watercourse is 11.5km, the width of the watercourse is 500-800 m, and the average water depth is 5-10 m. The plum mountain water channel is originally a tide channel, the average tidal range is 3.0m, the average flow velocity of the rising tide and the falling tide is about 0.3-0.5 m/s, the construction of the south and north dykes at the two ends of the water channel is implemented in 2012-2016, the hydrodynamic force in the water channel is greatly weakened after the south and north dykes are closed, and more than ten inland rivers are arranged around the water channel, so that the problem of the water environment in the water channel is increasingly prominent. The location of the ten-thousand people beach is at the north side of the south dike of the Meishan watercourse, near a red bridge of the North Meishan mountain, the south to south dike, the beach is generally arc-shaped, the total length of the beach is about 1.88 kilometers, the plane of the ten-thousand people beach is generally arc-shaped, and the arc radius of the sand blocking dike is about 340m, as shown in figure 1. The hydrodynamic force of local areas of the beach is weak, which easily causes the disaster problems of pollutant accumulation, poor water quality, easy red tide outbreak and the like.

In order to improve the hydrodynamic force, the embodiment provides a hydrodynamic lifting method, which specifically includes the following steps:

and S1, if the hydrodynamic lifting requirement is to increase the hydrodynamic force of the edge part of the hydrodynamic weak area, a plurality of water pump jet flow impellers are arranged at intervals on the edge part of the hydrodynamic weak area.

As shown in fig. 2 and 3, the water pump jet flow impeller includes a bottom plate 11, a water-stop plate 12, a plurality of buoys 13 (shown as 2) and a plurality of water pumps 14 (shown as 5); the floating pontoon 13 is arranged at two sides of the bottom plate 1, the other two sides of the bottom plate 11 are empty, the floating pontoon 13 is fixed through a connecting rod so that water can enter the bottom plate 11, the floating pontoon 13 is connected with a plurality of anchors 15 through anchor ropes, and for better stability, four anchors 15 can be arranged and respectively arranged at four corners at the bottom outside the floating pontoon 13; the water pumps 14 are horizontally arranged on the bottom plate 11 side by side, the water inlet of each water pump 14 is connected with a water inlet pipe 16, the length of each water inlet pipe is sequentially increased from the middle position to two sides, the characteristics of flow velocity distribution are met, the influence of non-uniform flow on water inlet can be reduced, the water outlet of each water pump is connected with a water outlet pipe 17, the lengths of all the water outlet pipes are consistent, and the interference among the water outlets can be reduced; the water-stop plate 12 is vertically fixed on the bottom plate 11, and separates the water inlet pipe 16 and the water outlet pipe 17 at two sides of the water-stop plate 12, so as to prevent the mutual interference of water inlet and outlet; when in use, the water pump jet flow impeller can float in water by adjusting the buoy 13 and the anchor 15, and the water pump, the water inlet pipe and the water outlet pipe on the bottom plate 11 are completely immersed in the water.

And S2, if the hydrodynamic lifting requirement is to increase the hydrodynamic force of the central part of the hydrodynamic weak area, placing the vertical shaft flow impeller in the center of the hydrodynamic weak area.

As shown in fig. 4, the vertical shaft flow driver includes a bracket 21, a motor 22, a flow pushing plate 23 and a vertical shaft 24, the motor 22 is fixed on the bracket 21, the motor 22 is connected to one end of the vertical shaft 24, the other end of the vertical shaft 24 is fixed with the flow pushing plate 23, specifically, fixed on the center line of the flow pushing plate 23, the flow pushing plate 23 is rectangular, and has a length of 1/15-1/3, and most preferably 1/10-1/5, which is the maximum radius of the hydrodynamic weak area, which is the value of dividing the maximum radius of the area by 2, because the shape of the hydrodynamic weak area is not fixed, the maximum radius of the area where hydrodynamic lifting effect is desired is taken as a measure. The support 21 comprises a plurality of support rods and a table top which is supported and fixed through the support rods, and the height of each support rod is larger than the distance from the bottom of the flow pushing plate to the table top of the support, so that the flow pushing plate can normally rotate.

And S3, if the hydrodynamic lifting requirement is that the device has both the entertainment function and the hydrodynamic lifting function, placing a suspension wave generator in the center of the hydrodynamic weak area.

As shown in fig. 5, the floating wave generator includes a motor 31, a crankshaft 32, a floating bracket (not shown), a connecting line 33, a pulley 34 and a buoy 35, the floating bracket can float on the water, the motor 31 and the pulley 34 are mounted on the floating bracket, the crankshaft 32 is fixed on the motor 31 and driven by the motor 31 to rotate, one end of the connecting line 33 is connected with the crankshaft 32, and the other end of the connecting line 33 bypasses the pulley 34 and is connected with the buoy 35 located under the floating bracket. Driven by the motor, the buoy 35 moves up and down to make waves, and the chassis of the buoy 35 can be round or square, and is round in figure 5.

The embodiment also provides a performance test method of the method, and particularly provides two test methods, wherein one test method is performed through a reduced physical model, and the other test method is performed through a mathematical model. Wherein, the reduced physical model relates to a scale, in this embodiment, the plane scale lambda_LUsing a normal model, 64, it can be assumed that each of the other scales is shown in table 1:

TABLE 1 summary of model scales

The method for testing by adopting the reduced physical model specifically comprises the following steps:

(one) the performance test of the water pump jet flow impeller in the step S1 is carried out according to the following method.

And S11, acquiring the hydrodynamic weak area and the size of the corresponding water pump jet flow impeller. The hydrodynamic weak area is a beach with thousands of people on a Meishan watercourse, the jet impeller of the water pump is 1200cm long, 1000cm wide and 200cm high, and the water inlet pipe and the water outlet pipe are both arranged on the bottom plate.

S12, establishing a physical model of the hydrodynamic weak area and the water pump jet flow impeller after being reducedWherein the reduction ratio is a preset plane scale lambda_L. The physical model of the hydrodynamic weak area is shown in fig. 6.

S13, acquiring a central point of the physical model of the hydrodynamic weak area, and placing the physical models of the water pump jet flow impeller on a circumference close to a bank by taking the central point as a circular point, wherein the direction of a water outlet pipeline of the water pump jet flow impeller is the tangential direction of the circumference; and s1 radial equally-spaced flow velocity measuring points are arranged by taking the circle center as a starting point, and s2 tangential equally-spaced section flow velocity measuring points are arranged on the circumference of each flow velocity measuring point.

In this embodiment, the central coordinate is X-640417.4659Y-93246.8982, and 3 sets of jet stream pushers (as shown in fig. 7) are arranged on a pseudo-plane according to the plane situation of the beach bay, the jet stream pusher a is about 30m from the shore, the jet stream ejector B, C, D is about 30m from the sand bank, and the coordinates are:

A：X＝640562.8871，Y＝93001.8738；

B：X＝640259.7018，Y＝92965.0909；

C：X＝640109.5557，Y＝93156.2029；

D：X＝640286.8689，Y＝93544.6013。

the center of an outlet pipeline of the jet device is arranged 1.4m below the water surface, and the direction of the jet outlet is the circumferential tangential direction around the center of the circular arc; during the test, two working condition tests with the jet flow direction being clockwise and anticlockwise are carried out, wherein the jet flow impeller is arranged at A, B, D in the clockwise process, and the jet flow impeller is arranged at D, C, A in the anticlockwise process. 5 flow velocity measuring points are arranged in the range of 20m and 40m between the inner side and the outer side of the sand blocking dam, and 6 tangential cross section flow velocity measuring points with equal angular intervals are arranged on the circumference of each flow velocity measuring point.

S14, setting n1 working conditions, specifically setting the water pump capacity of the water pump jet flow impeller to E₁,E₂,…,E_n1And according to the energy scale lambda_EConverting the set working condition to obtain the water pump capacity E of the physical model of the water pump jet flow impeller₁’,E₂’,…,E_n1', and according to E₁’,E₂’,…,E_n1' get the number of water pumps needed to be turned on, where,

i1＝1,…,n1。

in this embodiment, 3 working conditions are set, specifically, the water pump capacity of the water pump jet flow impeller is set to 5000m respectively³/h,10000m³/h,15000m³/h。

Energy scale lambda_EThe calculation process of (2) is as follows: area scale lambda_A＝(λ_L)²Ruler for comparing flow rate

Flow rate scale

Lambda of flow rate scale_QEnergy scale λ_E. In the embodiment, the energy scale is 32768, and the water pump capacity of the physical model of the water pump jet flow impeller can be obtained as 5000/32768-0.15 m³150L/h, 300L/h and 450L/h, and if the capacity of a single water pump is set to be 150L/h in the model, the number of the water pumps which need to be started under 3 working conditions can be respectively 1, two and three.

S15, starting the water pumps with the corresponding number according to the set working conditions to obtain a flow rate set V1 ' ═ V ' of all flow rate measuring points under all the working conditions '_j1|j1＝1,…,s1*s2}。

S16, all the flow rates in the flow rate set V1' are adjusted according to the flow rate scale lambda_vThe conversion is carried out to obtain that the flow velocity set in the natural state of the hydrodynamic weak area is V1 ═ V_j11, …, s1 s2}, wherein v is j1 ═ 1, …, s 3526 ═ s2}, in which v is a linear chain structure_j1＝λ_vv'_j1，

The flow velocity results of the hydrodynamic weak area in the natural state are shown in tables 2-7, and statistics of the left, middle and right flow velocity characteristic values of the sand blocking dam are shown in tables 8-10.

TABLE 2 flow rate near sand beach during jet propulsion(plug flow direction: clockwise, water pump capacity 5000m³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 3 flow rate characteristics table near sand beach when jet flow is pushed (push flow direction: counter-clockwise, water pump capacity 5000 m)³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 4 flow rate characteristics table near sand beach when jet flow is pushed (push flow direction: counter-clockwise, water pump capacity 10000 m)³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 5 flow Rate characteristics Table near Sand beach when jet flow impels (impel flow direction: counter clockwise, water pump capacity 10000m³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 6 flow Rate characteristics Table near Sand beach when jet flow is pushed (push flow direction: clockwise, water pump capacity 15000m³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 7 flow Rate characteristics Table near Sand beach when jet stream is pushed (push stream direction: counter clockwise, water pump capacity 15000m³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 8 along-the-way average flow rate characteristics (Water Pump Capacity 5000 m) near the Sand Block³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 9 in-path average flow rate characteristics (Water Pump Capacity 10000 m) near the Sand Block dam³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

TABLE 10 along-the-way average flow rate characteristics (Water Pump Capacity 15000 m) near the Sand Block³H, unit cm/s)

Remarking: c is a sand blocking embankment, and the distance between the points a, b, c, d and e is 20 m.

And S17, obtaining the performance of the water pump jet flow impeller according to the flow rate set as V1, wherein the larger the flow rate of the weak power area is, the better the hydrodynamic force lifting performance is.

From the final results, it can be seen that: under the conditions of three water pump jet capacities, strip exchange water flow around the circular arc circumference can be formed near the sand beach, and backflow with different degrees exists on the surface; exchange flow rate obtained counterclockwise with equal pump capacitySlightly greater than a clockwise flow rate; when the water pump capacity is 5000m3/h, spraying clockwise and anticlockwise, and obtaining flow rates near a sand blocking dam at the beach part of 13.39 cm/s and 13.79cm/s respectively; when the water pump capacity is 10000m3/h, spraying clockwise and anticlockwise, and respectively obtaining the flow velocity near the sand blocking dam at the beach part of 17.36 cm/s and 17.88 cm/s; the capacity of the water pump is 15000m³At the time of/h, the sand blocking agent is sprayed clockwise and anticlockwise, and the flow rates obtained near the sand blocking dam at the beach part are 22.13 cm/s and 22.53cm/s respectively. The experiment shows that the water pump ejector can form a better water flow exchange zone near the beach, and can enhance the water body exchange of beach parts, namely edge parts of hydrodynamic weak areas.

(II) for the vertical shaft flow pusher in the step S2, the performance test is carried out according to the following method.

And S21, acquiring the water power weak area and the size of the corresponding vertical shaft impeller.

According to the optimal proportion, if the arc radius of the sand-blocking embankment is about 340m, the length of the impeller plate of the vertical-axis impeller is 1/5 of 340m, but in order to study the effect of various proportions, the impeller plate is reduced in size, specifically, the height of the impeller plate is set to be 2.5m, the width of the impeller plate is set to be 10m (namely, the radius is 10m), and the rotating direction is clockwise.

S22, establishing a physical model of the hydrodynamic weak area and the reduced vertical shaft impeller, wherein the reduction scale is a preset plane scale lambda_L。

And the physical model after the hydrodynamic weak area is reduced is the same as the physical model. According to a plane scale, converting the vertical axis impeller into a physical model: the height 250/64 of the plug-flow plate is 3.9cm, and the diameter 2000/64 of the plug-flow plate is 31.25 cm.

S23, placing the physical model of the vertical shaft impeller in the center of the physical model of the hydrodynamic weak area, and setting S3 flow rate monitoring devices at radial intervals by taking the center point of a flow pushing plate of the physical model of the vertical shaft impeller as a starting point.

In this embodiment, 18 flow rate monitoring devices are provided at intervals, and the set distances and the corresponding distances in the actual natural state are shown in table 11.

Meter 11 flow rate monitoring device distance from axial line of flow pushing plate

S24, setting n2 working conditions, specifically setting the rotating speed of the motor of the vertical shaft impeller to w₁、w₂、…、w_n2And according to the rotation speed scale lambda_wConverting the set rotating speed to obtain the rotating speed w of the motor in the physical model of the vertical shaft impeller₁’、w₂’、…、w_n2', wherein,

i2＝1,…,n2。

in the embodiment, 4 working conditions are set, the rotating speeds are respectively 3.75, 5.0, 6.25 and 7.5r/min under the natural state, and the rotating speeds of the converted plug flow plate models are respectively 30, 40, 50 and 60r/min according to a rotating speed scale. As shown in table 12:

meter 12 different rotation speed working condition settings

	Experimental conditions of group 1	Experimental conditions of group 2	Experimental conditions of group 3	Experimental condition set 4
					Model rotation speed (r/min)	30	40	50	60
Natural rotating speed (r/min)	3.75	5	6.25	7.5

S25, according to the rotating speed w₁’、w₂’、…、w_n2'starting a motor to drive the flow pushing plate to rotate, and obtaining a flow rate set V2' ═ V 'monitored by the flow rate monitoring device at all rotating speeds'_i2j2L i2 ═ 1, …, n2, j2 ═ 1, …, s3}, where v'_i2j2Denotes a rotational speed w'_i2The flow rate monitored by the flow rate monitoring device j 2.

S26, all the flow rates in the flow rate set V2' are adjusted according to the flow rate scale lambda_vThe conversion is carried out to obtain that the flow velocity set in the natural state of the hydrodynamic weak area is V2 ═ V_i2j21, …, n2, j2, 1, …, s3, wherein v is2 | i_i2j2＝λ_vv’_i2j2，

In this example, the flow rates in the natural state obtained finally are shown in Table 13.

TABLE 13 average flow rate test result table for vertical line of outside water area of flow pushing plate (flow rate: m/s)

And S27, obtaining the performance of the vertical shaft impeller according to the flow velocity set V2, wherein the larger the flow velocity of the weak power area is, the better the hydrodynamic lifting performance is.

From the obtained flow rates: the average flow velocity of the water flow perpendicular line of the water area outside the thrust plate is inversely proportional to the distance from the axial line of the thrust plate, and the area with larger influence on the flow velocity of the water flow by the thrust plate is concentrated in the range (100m) of 10 times of the length radius (10m) of the thrust plate; when the rotating speed is 3.75 r/min, 5.0 r/min, 6.25 r/min and 7.5r/min, the average flow velocity of the vertical line at the position 100m outside the axial line of the flow pushing plate is 0.07 m/s, 0.09 m/s, 0.13 m/s and 0.15m/s respectively; (2) the change of the flow velocity of the water flow beyond 100m outside the flow pushing plate and the distance from the flow pushing plate to the axis of the flow pushing plate becomes gentle, namely the influence is gradually smaller, the flow velocity at the position 340m away from the axis of the flow pushing plate, namely the flow velocity near the sand blocking dam, is respectively 0.005, 0.01, 0.015 and 0.02m/s when the rotating speed is 3.75, 5.0, 6.25 and 7.5r/min, and therefore, the flow pushing plate has a certain pulling effect on the water flow at the position of the sandy beach; (3) the flow velocity of water flow in the radius range of the thrust plate is large, for example, at the rotating speed of 3.75, 5.0, 6.25 and 7.5r/min according to the rotating speed of the plate, the speed of the edge of the thrust plate reaches 3.93, 5.23, 6.54 and 7.85m/s respectively, and the flow velocity is transmitted to the surface of the seabed, so that the scouring of the seabed is inevitably caused, and therefore, if the flow is increased in such a way, the seabed around the thrust plate must be protected.

The tests show that the flow pushing plate plays a role in pulling water flow within a certain range, when the length of the flow pushing plate is 20 meters, a certain water flow pulling role is played in an area which is about 300 meters away from the center of the flow pushing plate, the flow pushing plate cannot be arranged too large without limitation, and therefore 1/3 which does not exceed the radius of the area to the maximum extent is the best, and the arrangement proportion of the flow pushing plate is proved to be 1/15-1/3. In addition, the area with larger water flow pulling action is about 100 meters in radius, and the flow velocity can still reach 0.03-0.06 cm/s in the range of about 200 meters in radius, so the optimal length proportion of the flow pushing plate is 1/10-1/5. Finally, the flow increasing speed of the sand beach near the sand blocking dam is 0.5-2.0 cm/s, plane rotating flow is formed in a certain range outside the flow pushing plate, the flow speed value is large in the rotating range of the flow pushing plate, strong disturbance can be generated on the bottom of the seabed, scouring can be generated, and if the flow increasing mode is adopted, the seabed in a certain range near the flow pushing plate needs to be protected against scouring.

And (III) performing performance test on the suspension wave maker in the step S3 according to the following method.

And S31, acquiring the size of the hydrodynamic weak area.

S32, establishing a physical model after the hydrodynamic weak area is reduced, wherein the reduction scale isFor presetting a plane scale lambda_L。

S33, randomly selecting S4 monitoring points in the hydrodynamic weak area physical model to arrange wave height monitoring equipment.

In the embodiment, 12 monitoring points are arranged around the beach, a red bridge, a south dike and the like, the positions of the measuring points are shown in fig. 8, and the specific positions are #1 to #12 shown in fig. 8.

S34, setting m x n3 working conditions, specifically setting the diameter or side length of a float bowl in the suspension wave making device as r₁、r₂、…、r_mThe amplitude of the float is h₁、h₂、…、h_n3According to the plane scale lambda_LConverting the set working conditions to obtain m × n3 working conditions of the physical model of the suspended wave generator, specifically the diameter or the side length r₁’、r₂’、…、r_n3The amplitudes of the buoys are h₁’、h₂’、…、h_n3The method of' wherein, in the step of,

i3＝1,..,m，j3＝1,…,n3。

in this embodiment, m is 3, n3 is 3, the pontoon base plate is circular in the natural state, the diameters are 10, 19m and 32m, the amplitudes are 4, 5 and 6m (corresponding to the crank radii being 2.0, 2.5 and 3.0m), the oscillation frequency is about 60 times/min in the natural state, and the oscillation frequency is 7.5 times/min in the model. The physical model of the hydrodynamic lifting device is specifically shown in fig. 4, and is installed at the center of the circular arc of the beach, and the coordinates of the model are as follows: x-640417.4659, Y-93246.8982; the test was carried out at a water level of 1.0 m.

S35, starting the motor according to preset working conditions to obtain a wave height set A ' ═ a ' under all working conditions '_lL-m-n 3 s4 and wave period set T '{ T'_l|l＝m*n3*s4}。

S36, all the wave amplitudes in the wave height set A' are adjusted according to the plane scale lambda_LConverting all wave periods in the wave period set T' according to a period scale lambda_TConverting to obtain the wave in the natural state of the hydrodynamic weak areaAmplitude set a ═ a_lL-m-n 3 s4 and wave period set T-T_lI | m ═ n3 | s4}, wherein a is_l＝λ_La’_l，t_l＝λ_Tt’_l，

The results of the test, finally converted to the natural state, are shown in tables 14 to 18:

TABLE 14 statistical table of wave element characteristic values (buoy diameter 10.0m)

TABLE 15 statistical table of wave element characteristic values (float diameter 19.0m)

TABLE 16 statistical table of wave element characteristic values (float diameter 32.0m)

TABLE 17 statistical table for wave height factors of west retaining wall and wave making of south dyke

Table 18 statistics table for high value of sand beach wave

And S37, obtaining the performance of the suspended wave maker according to the wave height set A and the wave period set T, wherein the higher the wave height in the weak power area is, the better the hydrodynamic force lifting performance is.

According to experimental results, the suspended wave generator can generate waves with different wave heights, when the diameter of the chassis is 10m, the wave height of a beach part is 0.33-0.53 m, when the diameter of the chassis is 19m, the wave height of the beach part is 0.40-0.57 m, and when the diameter of the chassis is 32m, the wave height of the beach part can reach 0.76-1.13 m.

Another performance testing method provided in this embodiment is implemented by mathematical modeling, and specifically includes the following steps:

s41, establishing a hydrodynamic mathematical model of the hydrodynamic weak area, which specifically comprises the following steps:

(1) mass continuity equation:

wherein u, v, w are the velocity components in three directions of a Cartesian coordinate system x, y and z, A_x,A_y,A_zIs the fractional area of the flow in the x, y, z directions, respectively, ρ is the fluid density, R_SORA density source term that can be used to simulate mass injection, for example, through the surface of a porous barrier;

(2) the momentum equation:

in the formula, G_x,G_y,G_zRespectively x, x,Gravitational acceleration in three directions of y and z; f. of_x,f_y,f_zThe viscous force acceleration in the x direction, the y direction and the z direction respectively; item U_w＝(u_w，v_w，w_w) Representing the velocity of the source assembly in three directions; item U_s＝(u_s，v_s，w_s) Representing the velocity of the fluid at the source surface in three directions relative to the source itself; v_FThe fluid volume fraction with a free surface, R is a coordinate coefficient, when a Cartesian coordinate system is selected, the value is1, a coefficient is represented, when 0 is taken, the pressure boundary condition is a stagnation type, and when 1 is taken, the pressure boundary condition is a static pressure type;

(3) a turbulence model:

in the formula, k_TIs kinetic energy of turbulence, P_TFor the turbulence-generating term, G_TIn order to generate the term for the buoyancy,

in order to be a diffusion term, the diffusion term,_Tfor turbulence energy dissipation ratio, RMTKE, CDIS1 and CNU are user-defined parameters with default values of 1.39, 1.42 and 0.085, respectively, CDIS2 is defined by k_TAnd P_TIs calculated to obtain v_TIs a kinematic turbulent viscosity; μ is the molecular dynamic viscosity; ρ is the fluid density; p is pressure; CHRO is another turbulence parameter with a default value of 0.0, but for thermally buoyant flow, should be chosen to be about 2.5; upsilon is_kIs k_TAnd is calculated based on local values of the turbulence viscosity. The user-defined parameter RMTKE is the viscosity coefficient (the value defaults to 1.0) used to calculate the turbulent diffusion coefficient.

(4) Fluid distribution:

the fluid distribution is defined in terms of a fluid volume function F (x, y, z, t) that represents the volume of fluid #1 per unit volume and satisfies the following equation:

in the formula: f is an abbreviation for the function F (x, y, z, t), ζ is the coordinate coefficient whose value is 0, ν when a Cartesian coordinate system is used_FAs diffusion coefficient, F_SORIs the density source term, which is the volume fraction time rate of change of fluid #1 associated with the mass source. The interpretation of item F depends on the type of problem to be solved, the incompressible problem must involve a single fluid or two fluids with free surfaces and no free surfaces. For a single fluid, the term F represents the volume fraction occupied by the fluid. Thus, there is a fluid, where the term F is1, and the void region corresponds to the location of F0. "voids" are areas of no fluid mass that have a uniform pressure assigned to them. Physically, they represent areas filled with vapor or gas, the density of which is negligible with respect to the density of the fluid.

S42, obtaining the boundary of the hydrodynamic weak area, dividing the boundary into a plurality of grids by adopting a hexahedral structured grid, setting the periphery and the bottom of the hydrodynamic weak area to be non-displacement Wall boundaries, setting the top to be a pressure boundary, setting the atmospheric pressure to be 1.01 × 105Pa, and setting the fluid fraction to be 0, wherein the boundary represents that the hydrodynamic weak area is completely air.

S43, establishing a mathematical model of the water pump jet flow impeller, obtaining a central point of the hydrodynamic weak area, placing the water pump jet flow impellers on a circumference of the hydrodynamic weak area close to the bank by taking the central point as a circular point, and taking the direction of a water outlet pipeline of the water pump jet flow impeller as the tangential direction of the circumference; setting n1 working conditions, specifically setting the water pump capacity of the water pump jet flow impeller to E respectively₁,E₂,…,E_n1。

In the embodiment, the power of each water pump is 5000m 3/h. 3 working conditions, A, B and C of the working condition 1, 3 positions are designed, and 1 water pump is placed at each position; 2 water pumps are placed at each position in the working condition 2; working condition 3 water pumps were placed at each position. As shown in table 19. Fig. 9 is a schematic diagram of the water pump placement.

Design of working condition of watch 19

S44, establishing a mathematical model of the vertical shaft impeller, and placing the mathematical model in the center of the hydrodynamic weak area; and setting n2 working conditions, specifically setting the rotating speed of the flow pushing plate of the hydrodynamic lifting device to w₁、w₂、…、w_n2。

The working condition is the same as that of the physical model test.

S45, establishing a mathematical model of the suspended wave making device, and placing the mathematical model in the center of the hydrodynamic weak area; and setting m x n3 working conditions, specifically setting the diameter or side length of the buoy of the hydrodynamic lifting device as r₁、r₂、…、r_mThe amplitude of the float is h₁、h₂、…、h_n3The operating conditions of (1).

Design of working condition of watch 20

The numerical simulation adopts a wave-making working condition, the diameters of the lower chassis are respectively 10m, 19m and 32m, the amplitudes are respectively 4m, 5m and 6m (the crank shaft radiuses are respectively 2.0m, 2.5m and 3.0m), and the oscillation frequency is about 60 times/min. There were 9 conditions in total, as shown in Table 20.

And S46, respectively starting according to set working conditions, tracking free surface flow through the established hydrodynamic mathematical model, determining the position of the free liquid level, and performing discrete solution and GMRES implicit solver calculation on the model based on a finite difference method to obtain the velocity distribution of each region under all the working conditions.

The finite difference method comprises the following solving steps:

(1) an explicit approximation is made by the momentum equation for calculating the initial conditions for all advection, pressure and other accelerations, or the first guess of a new time-level velocity from a previous time-level value.

(2) To satisfy the mass continuity equation, when the implicit option is used, the pressure is iteratively adjusted in each cell and the velocity change caused by each pressure change is added to the velocity calculated in step (1). Iterations are required because the pressure changes required in one cell will upset the balance in six adjacent cells. In explicit calculations, iterations can still be performed within each cell to satisfy the state equations of the compressible problem.

(3) Finally, when a free surface or fluid interface is present, it is updated with the formula for the fluid distribution to provide a new fluid distribution. For compressibility problems, the density and energy must be updated to reflect advection, diffusion and source processes.

(4) And repeating the steps to gradually approach to the precise solution within the calculation time. Of course, in each step, appropriate boundary conditions must be applied across all meshes, obstacles and free boundary surfaces.

In the research, a finite difference method is adopted to solve a calculation region after dispersion, and grids are uniformly set to be cubes, so that the calculation precision and efficiency are improved.

In addition to the GMRES solver, F L OW3D also provides a new alternative algorithm, the Generalized Conjugate Gradient (GCG) algorithm, for solving the sticky term in the new GMRES solver.

And S47, obtaining the performance of the hydrodynamic lifting device according to the speed distribution of each region under each working condition, wherein the larger the flow speed is, the better the hydrodynamic lifting performance is.

The final mathematical model test results are:

(1) jet flow impeller of water pump

A flow velocity distribution diagram at a section of 1.15m below the horizontal plane (the horizontal plane is a plane where Z is 0m, that is, Z is-1.15 m) is extracted), and the flow velocity distribution in the vicinity of the sand bank and the flow velocity distribution in the entire hydrodynamic weak area are analyzed. Fig. 10 shows the flow velocity distribution of the entire hydrodynamic weak region from condition 1 to condition 3. As can be seen from fig. 10, after the water pumps are placed at A, B and C, the hydrodynamic weak areas are improved to different degrees, the flow velocity near the sand bank is improved to different degrees, and the maximum flow velocity near the sand bank is increased with the increase of the power of the water pumps. The areas with the largest flow velocity are all arranged near the center of the water pump jet flow, the maximum flow velocity of the water pump jet flow center under the working condition 1 can reach 0.4m/s, and the maximum flow velocities under the working conditions 2 and 3 can reach 0.55m/s and 0.6m/s respectively. In the part near the center of the circle of the hydrodynamic weak area, the influence of the water pump jet flow on the part is small because the part is far away from the water pump jet flow, the working condition is1 to 3, and the flow speed of the area near the center of the circle of the hydrodynamic weak area is between 0.05m/s and 0.1 m/s. Physical model experiments and numerical simulation calculation results show that the lifting effect of the hydrodynamic weak area is obvious.

(2) Vertical shaft flow impeller

As a result of the logarithmic simulation, a flow velocity distribution diagram at a cross section of 1m below the horizontal plane (a plane where Z is 0m, that is, Z is-1 m) was extracted, and the flow velocity distribution in the vicinity of the vertical-axis thrust plate and the flow velocity distribution in the vicinity of the sand bank were analyzed. Fig. 11 shows the flow velocity distribution near the vertical axis thrust plate, and fig. 12 shows the overall flow velocity distribution of the ten-thousand-person beach. As can be seen from FIG. 11, the region of maximum flow velocity occurs at the top of the vertical thrust plate, and the maximum flow velocity can reach 0.4 m/s. The flow velocity is between 0.05m/s and 0.4m/s within an influence radius of about 2 times the length of the vertical axis thrust plate; beyond the influence radius of about 2 times the length of the vertical axis thrust plate, the flow velocity is reduced to below 0.05 m/s. As can be seen from FIG. 12, the flow velocity near the sand bank is substantially between 0m/s and 0.05m/s, the vertical axis thrust plate hardly affects the sand bank, and the improvement effect of the hydrodynamic weak area is limited.

(3) Suspension wave maker

Because of the numerous conditions, only typical conditions (32 m lower chassis diameter and 4m amplitude) were selected for display. As a result of the logarithmic simulation, a flow velocity distribution diagram at a cross section of 1m below the horizontal plane (a plane where Z is 0m, that is, Z is-1 m) was extracted, and the flow velocity distribution in the vicinity of the wave maker and the flow velocity distribution in the vicinity of the sand bank were analyzed. As can be seen from fig. 13 and 14, the flow velocity gradually decreases from the center of the wave maker to the periphery. The area with the largest flow velocity is around the wave making machine, and the maximum flow velocity exceeds 0.6 m/s. The flow velocity rapidly decreases to below 0.15m/s, substantially between 0.05m/s and 0.15m/s, beyond about 50m from the edge of the wave maker. The wave maker has a limited range of influence, and the flow velocity rapidly decreases to below 0.15m/s beyond about 50m from the edge of the wave maker. The flow velocity is substantially between 0.05m/s and 0.15m/s in the vicinity of the sand bank. The wave maker has little influence on the east of the sand beach of tens of thousands of people, and the flow speed is basically below 0.05 m/s. Through the experiment, when the travelling and entertainment requirements are met on the beach, the manual wave making measures can be adopted. The physical model experiment shows the wave heights generated at different positions of the sand beach when the wave maker is combined with different amplitudes and different chassis diameters. The numerical simulation calculation result of the working condition with the chassis diameter of 32m and the amplitude of 4m shows that the flow velocity near the sand blocking dam is between 0.05m/s and 0.15m/s, and other working conditions can obtain similar results. The decision maker can select a proper wave maker according to the actual requirement on the generated wave height.

The results of the above physical model test and mathematical model test are known as follows:

(1) for the vertical plug flow scheme, 4 different rotating speed working conditions are designed in a physical model experiment, and the result shows that the flow velocity near the sand blocking dam is between 0.005m/s and 0.02 m/s. The flow velocity at the edge of the plug flow plate is large, so that the scouring of the seabed is caused, the seabed around the plug flow plate needs to be protected, and the construction cost is greatly increased. The numerical simulation carries out an important research on 1 working condition, and the result shows that the influence area of the thrust plate is mainly near the center of a circle of a beach of all people, the flow velocity is rapidly reduced to be below 0.05m/s outside the influence radius of about 2 times of the length of the vertical shaft impeller, the influence on the sand blocking embankment is limited, and the lifting effect of the hydrodynamic weak area is not obvious.

(2) As for the water pump jet scheme, the results of physical model experiments show that the flow velocity near the sand bank can reach 0.14m/s, 0.18m/s and 0.23m/s when the water pump capacity is 5000m3/h, 10000m3/h and 15000m3/h respectively. The numerical simulation result shows that the flow velocity is smaller and basically ranges from 0.05m/s to 0.1m/s near the center of the ten-thousand beach sand because the distance from the water pump is far; near the sediment trapping dyke, influenced by the water pump, the velocity of flow near the sediment trapping dyke all obtains the improvement of different degree, and along with the increase of water pump ability, the effect of promotion is more obvious. When the water pump capacity is 5000m3/h, the flow velocity near the sand blocking dam is increased to 0.05m/s to 0.15 m/s; when the water pump capacity is 10000m3/h, the flow velocity near the sand blocking dam is increased to 0.05-0.2 m/s; when the water pump capacity is 15000m3/h, the flow velocity near the sand-blocking dam is increased to 0.1m/s to 0.25 m/s. Physical model experiments and numerical simulation calculation results show that the lifting effect of the hydrodynamic weak area is obvious.

(3) When there is a travel and entertainment need for the beach, a wave making scheme can be used. The physical model experiment shows the wave heights generated at different positions of the sand beach when the wave maker is combined with different amplitudes and different chassis diameters. The numerical simulation calculation result of the working condition with the chassis diameter of 32m and the amplitude of 4m shows that the flow velocity near the sand blocking dam is between 0.05m/s and 0.15m/s, and other working conditions can obtain similar results. The decision maker can select a proper wave maker according to the actual requirement on the generated wave height.

To sum up, if the hydrodynamic force lifting demand is for improving the hydrodynamic force of the edge part of the hydrodynamic force weak area, the water pump jet flow impeller is used, if the hydrodynamic force lifting demand is for improving the hydrodynamic force of the central part of the hydrodynamic force weak area, the vertical shaft impeller is adopted, and if the hydrodynamic force lifting demand is for having the entertainment function and the hydrodynamic force lifting function, the suspension wave generator is adopted. In addition, the engineering scheme of the hydrodynamic weak area is promoted, and the water pump jet scheme is recommended preferentially. In actual engineering, the construction cost and the actual requirement can be considered, and the proper number of the water pumps can be selected. When the tourism and entertainment functions of the beach are considered, a wave making scheme is considered.

The physical model experiment and the numerical simulation result are relatively close, but certain errors exist, because the errors are limited by the calculation capability of a computer, in order to reduce the calculation grid as much as possible, the calculation range of the numerical simulation is smaller than that of the physical model experiment, so that the errors exist, the results take the physical model as the reference, and the numerical simulation result is taken as the reference.

Claims (6)

1. A hydrodynamic lifting method, characterized by the steps of:

s1, if the hydrodynamic force lifting demand is to improve the hydrodynamic force of the edge part of the hydrodynamic force weak area, placing a plurality of water pump jet flow impellers at intervals on the edge part of the hydrodynamic force weak area, wherein each water pump jet flow impeller comprises a bottom plate, a water stop sheet, a plurality of buoys and a plurality of water pumps, the buoys are arranged on two sides of the bottom plate and connected with a plurality of anchors through anchor ropes, the water pumps are arranged on the bottom plate side by side, a water inlet pipe is connected to a water inlet of each water pump, the length of each water inlet pipe is sequentially increased from the middle position to two sides, a water outlet of each water pump is connected with a water outlet pipe, the lengths of all the water outlet pipes are consistent, the water stop sheet is vertically fixed on the bottom;

s2, if the hydrodynamic lifting demand is to improve the hydrodynamic force of the central part of the hydrodynamic weak area, placing a vertical shaft flow impeller in the center of the hydrodynamic weak area, wherein the vertical shaft flow impeller comprises a support, a motor, a flow pushing plate and a vertical shaft, the motor is fixed on the support, the motor is connected with one end of the vertical shaft, the other end of the vertical shaft is fixed with the flow pushing plate, the flow pushing plate is rectangular, and the length of the flow pushing plate is 1/15-1/3 of the maximum radius of the hydrodynamic weak area;

s3, if hydrodynamic force promotes the demand and for having entertainment function and hydrodynamic force lifting function concurrently, then place the suspension in the weak regional center of hydrodynamic force and make unrestrained ware, the suspension is made unrestrained the ware and is included motor, bent axle, float support, connecting wire, pulley and flotation pontoon, the motor with the pulley mounting is in float on the support, the bent axle is fixed on the motor, connecting wire one end is connected the bent axle, the other end is walked around the pulley and is located the flotation pontoon under the support and be connected.

2. The hydrodynamic lifting method of claim 1, wherein: the length of a flow pushing plate of the vertical shaft flow pusher is 1/10-1/5 of the maximum radius of a hydrodynamic weak area.

3. The hydrodynamic lifting method of claim 1, wherein: the water pump jet flow impeller is provided with four anchors which are respectively arranged at four corners of the bottom of the outer side of the floating barrel.

4. The hydrodynamic lifting method of claim 1, wherein: and the vertical shaft of the vertical shaft flow impeller is fixed on the central line of the flow impeller.

5. A method for testing the performance of the hydrodynamic lift method of claim 1, comprising the steps of:

the performance of the water pump jet flow impeller in the step S1 is tested according to the following method:

s11, acquiring a hydrodynamic weak area and the size of the corresponding water pump jet flow impeller;

s12, establishing a physical model of the hydrodynamic weak area and the water pump jet flow impeller after reduction, wherein the reduction scale is a preset plane scale lambda_L；

S13, acquiring a central point of the physical model of the hydrodynamic weak area, and placing the physical models of the water pump jet flow impeller on a circumference close to a bank by taking the central point as a circular point, wherein the direction of a water outlet pipeline of the water pump jet flow impeller is the tangential direction of the circumference; taking the circle center as a starting point, arranging s1 radial equally-spaced flow velocity measuring points, and arranging s2 tangential equally-spaced section flow velocity measuring points on the circumference of each flow velocity measuring point;

s14, setting n1 working conditions, specifically setting the water pump capacity of the water pump jet flow impeller to E₁,E₂,…,E_n1And according to the energy scale lambda_EConverting the set working condition to obtain the water pump capacity E of the physical model of the water pump jet flow impeller₁’,E₂’,…,E_n1', and according to E₁’,E₂’,…,E_n1' get the number of water pumps needed to be turned on, where,

s15, starting the water pumps with the corresponding number according to the set working conditions to obtain a flow rate set V1 ' ═ V ' of all flow rate measuring points under all the working conditions '_j1|j1＝1,…,s1*s2}；

S16, all the flow rates in the flow rate set V1' are adjusted according to the flow rate scale lambda_vThe conversion is carried out to obtain that the flow velocity set in the natural state of the hydrodynamic weak area is V1 ═ V_j11, …, s1 s2}, wherein v is j1 ═ 1, …, s 3526 ═ s2}, in which v is a linear chain structure_j1＝λ_vv'_j1，

S17, obtaining the performance of the water pump jet flow impeller according to the flow rate set as V1, wherein the larger the flow rate of a weak power area is, the better the hydrodynamic force lifting performance is;

the performance test of the vertical shaft flow pusher in the step S2 is carried out according to the following method:

s21, acquiring the hydrodynamic weak area and the size of the corresponding vertical shaft impeller;

s22, establishing a physical model of the hydrodynamic weak area and the reduced vertical shaft impeller, wherein the reduction scale is a preset plane scale lambda_L；

S23, placing the physical model of the vertical shaft impeller in the center of the physical model of the hydrodynamic weak area, and setting S3 flow rate monitoring devices at radial intervals by taking the center point of a thrust plate of the physical model of the vertical shaft impeller as a starting point;

s24, setting n2 working conditions, specifically setting the rotating speed of the motor of the vertical shaft impeller to w₁、w₂、…、w_n2And according to the rotation speed scale lambda_wConverting the set rotating speed to obtain the rotating speed w of the motor in the physical model of the vertical shaft impeller₁’、w₂’、…、w_n2', wherein,

s25, according to the rotating speed w₁’、w₂’、…、w_n2'starting a motor to drive the flow pushing plate to rotate, and obtaining a flow rate set V2' ═ V 'monitored by the flow rate monitoring device at all rotating speeds'_i2j2L i2 ═ 1, …, n2, j2 ═ 1, …, s3}, where v'_i2j2Denotes a rotational speed w'_i2The flow rate monitored by the flow rate monitoring device j 2;

s26, all the flow rates in the flow rate set V2' are adjusted according to the flow rate scale lambda_vThe conversion is carried out to obtain that the flow velocity set in the natural state of the hydrodynamic weak area is V2 ═ V_i2j21, …, n2, j2, 1, …, s3, wherein v is2 | i_i2j2＝λ_vv'_i2j2，

S27, obtaining the performance of the vertical shaft impeller according to the flow velocity set V2, wherein the larger the flow velocity of the weak power area is, the better the hydrodynamic force lifting performance is;

the performance test is carried out on the suspended wave maker in the step S3 according to the following method:

s31, acquiring the size of the hydrodynamic weak area;

s32, establishing a physical model after the hydrodynamic weak area is reduced, wherein the reduction scale is a preset plane scale lambda_L；

S33, randomly selecting S4 monitoring points in the hydrodynamic weak area physical model to arrange wave height monitoring equipment;

s34, setting m x n3 working conditions, specifically setting the diameter or side length of a float bowl in the suspension wave making device as r₁、r₂、…、r_mThe amplitude of the float is h₁、h₂、…、h_n3According to the plane scale lambda_LConverting the set working conditions to obtain m × n3 working conditions of the physical model of the suspended wave generator, specifically the diameter or the side length r₁’、r₂’、…、r_n3The amplitudes of the buoys are h₁’、h₂’、…、h_n3The method of' wherein, in the step of,

s35, starting the motor according to preset working conditions to obtain a wave height set A ' ═ a ' under all working conditions '_lL-m-n 3 s4 and wave period set T '{ T'_l|l＝m*n3*s4}；

S36, all the wave amplitudes in the wave height set A' are adjusted according to the plane scale lambda_LConverting all wave periods in the wave period set T' according to a period scale lambda_TConverting to obtain a wave amplitude set A ═ a in a natural state in the hydrodynamic weak region_lL-m-n 3 s4 and wave period set T-T_lI | m ═ n3 | s4}, wherein a is_l＝λ_La'_l，t_l＝λ_Tt'_l，

And S37, obtaining the performance of the suspended wave maker according to the wave height set A and the wave period set T, wherein the higher the wave height in the weak power area is, the better the hydrodynamic force lifting performance is.

6. A method of testing the performance of the hydrodynamic lifting method of claim 1, wherein the method comprises: the method comprises the following steps:

s41, establishing a hydrodynamic mathematical model of the hydrodynamic weak area, which specifically comprises the following steps:

(1) mass continuity equation:

wherein u, v, w are Cartesian seatsThe velocity components in the three directions x, y and z, A_x,A_y,A_zIs the fractional area of the flow in the x, y, z directions, respectively, ρ is the fluid density, R_SORIs a density source item;

(2) the momentum equation:

in the formula, G_x,G_y,G_zThe gravity acceleration in the x direction, the y direction and the z direction respectively; f. of_x,f_y,f_zThe viscous force acceleration in the x direction, the y direction and the z direction respectively; item U_w＝(u_w，v_w，w_w) Representing the velocity of the source assembly in three directions; item U_s＝(u_s，v_s，w_s) Representing the velocity of the fluid at the source surface in three directions relative to the source itself; v_FThe fluid volume fraction with a free surface, R is a coordinate coefficient, when a Cartesian coordinate system is selected, the value is1, a coefficient is represented, when 0 is taken, the pressure boundary condition is a stagnation type, and when 1 is taken, the pressure boundary condition is a static pressure type;

(3) a turbulence model:

in the formula, k_TIs kinetic energy of turbulence, P_TFor the turbulence-generating term, G_TFor buoyancy-generating terms, Diff_kTIn order to be a diffusion term, the diffusion term,_Tfor turbulence energy dissipation ratio, RMTKE, CDIS1 and CNU are user-defined parameters with default values of 1.39, 1.42 and 0.085, respectively, CDIS2 is defined by k_TAnd P_TIs calculated to obtain v_TIs a kinematic turbulent viscosity;

(4) fluid distribution:

the fluid distribution is defined in terms of a fluid volume function F (x, y, z, t) that represents the volume of fluid #1 per unit volume and satisfies the following equation:

in the formula: f is an abbreviation for the function F (x, y, z, t), ζ is the coordinate coefficient whose value is 0, ν when a Cartesian coordinate system is used_FAs diffusion coefficient, F_SORIs the density source term, is the volume fraction time rate of change of fluid #1 associated with the mass source;

s42, obtaining the boundary of the hydrodynamic weak area, dividing the boundary into a plurality of grids by adopting a hexahedral structured grid, setting the periphery and the bottom of the hydrodynamic weak area to be non-displacement Wall boundaries, setting the top to be a pressure boundary, setting the atmospheric pressure to be 1.01 × 105Pa, and setting the fluid fraction to be 0, wherein the boundary represents that the hydrodynamic weak area is completely air;

s43, establishing a mathematical model of the water pump jet flow impeller, obtaining a central point of the hydrodynamic weak area, placing the water pump jet flow impellers on a circumference of the hydrodynamic weak area close to the bank by taking the central point as a circular point, and taking the direction of a water outlet pipeline of the water pump jet flow impeller as the tangential direction of the circumference; setting n1 working conditions, specifically setting the water pump capacity of the water pump jet flow impeller to E respectively₁,E₂,…,E_n1；

S44 vertical shaft flow pusherThe mathematical model of (2) is placed in the center of the hydrodynamic weak area; and setting n2 working conditions, specifically setting the rotating speed of the flow pushing plate of the hydrodynamic lifting device to w₁、w₂、…、w_n2；

S45, establishing a mathematical model of the suspended wave making device, and placing the mathematical model in the center of the hydrodynamic weak area; and setting m x n3 working conditions, specifically setting the diameter or side length of the buoy of the hydrodynamic lifting device as r₁、r₂、…、r_mThe amplitude of the float is h₁、h₂、…、h_n3The working condition of (1);

s46, starting according to set working conditions respectively, tracking free surface flow through the established hydrodynamic mathematical model, determining the position of a free liquid level, and performing discrete solution and GMRES implicit solver calculation on the model based on a finite difference method to obtain velocity distribution of each region under all the working conditions;

and S47, obtaining the performance of the hydrodynamic lifting device according to the speed distribution of each region under each working condition, wherein the larger the flow speed is, the better the hydrodynamic lifting performance is.

Images