KR101487846B1 - Method for analyzing 2D shallow water flow through assignment of wetting/drying condition using critical drying depth method - Google Patents

Abstract

The present invention relates to a method for analyzing a 2D shallow water flow through the assignment of a wetting/drying condition using a critical drying depth method. The purpose of the present invention is to provide the method for analyzing the 2D shallow water flow through the assignment of the wetting/drying condition using the critical drying depth method, capable of obtaining a result with high stability by solving a divergence problem in a dry area generated in an existing model without generating a new lattice according to a boundary condition and a specific simulation method in a shallow water equation model configuration. The present invention controls a problem of a discontinuous boundary surface and prevents an abnormal water depth simulation result and a high flow in the dry area. Thereby, the present invention efficiently and stably analyzes the shallow water flow.

Description

[0001] The present invention relates to a method for analyzing a two-dimensional flow stream through the provision of a drying / wetting condition using a critical drying water depth technique,

The present invention relates to a method for analyzing a two-dimensional water flow through the application of a dry / wet condition using a critical declining water depth technique, and more particularly, to a method for analyzing a two- And it is possible to solve the problem of divergence in the dry area mainly occurring in the existing model and to obtain a stable result by using the critical declining water depth technique, And the like.

In river and estuary areas, the width is much wider than the depth of water. Therefore, it is widely used to find the average flow velocity field for longitudinal and transverse flow velocities. Numerical modeling of the shallow water equation obtained by integrating the three - dimensional continuity equation and the momentum equation with time integration and depth - of - field can be used to obtain the flow velocity and depth in the horizontal two - dimensional plane by inputting the terrain data, boundary conditions and parameters. The solution of the equations can be used to analyze hydraulic behavior in designing and designing hydraulic structures such as dams and bridges, and can be used to predict erosion and sedimentation due to turbulence and turbulent distribution. Also, the flow velocity field calculated by the water flow analysis model is used as input data to analyze the problem of contamination diffusion and similar transfer, and in the ecological model, it is also used to calculate the fitness of fish form.

Most of the river flow analysis model analyzes the flow in the constructed grid, so that low depth or dry section occurs in the inner and outer sides of the river according to the temporal change of the water level in the actual river simulation when the terrain is complicated. Thus, the numerical solution becomes unstable . Especially, Korea has high flood coefficient, so it has a large variation of flood level and high water level during flood year, so it is essential to apply a dry area treatment technique to ensure stability of numerical analysis in long - term simulation. In addition, when modeling in estuaries and coastal areas, the boundary treatment according to time series or the presence of water in the area in order to simulate the continuous change of the water level due to the influence of the tide increases the complexity of area classification or simulation of numerical analysis do. Because the flow of water body has a great influence on the surrounding structures and the environment, it is necessary to accurately reproduce the phenomenon of wicking / wetting of nodes occurring in the simulation region according to the increase or decrease of the water depth, It is very important in the flow analysis.

In previous studies, to reflect this phenomenon, we used a method of predicting the water level in advance and then performing the simulation by removing the topological grid corresponding to the boundary or island corresponding to the slope, , And the method of simulating the terrain by interpreting the terrain as a permeable layer like a swamp has been carried out.

In the present invention, in order to compensate the physical incompatibility and numerical instability of these techniques, it is necessary to maintain the lattice generated at the initial stage of the simulation without deforming the boundary line and to change the floor friction coefficient We propose a critical depth water depth method that gives the flow velocity to zero. The present invention has an advantage in that when the flux at the nodal point is blocked due to blotting at the critical point, intrinsic velocity is generated in the blotted region to prevent abnormal flow velocity and depth simulated results from being derived, thereby facilitating smooth flow of water flow.

Meanwhile, Korean Unexamined Patent Publication No. 10-2011-0130821 (Dec. 2011) discloses a finite element numerical analysis method of a fluid flow using a roughening / wetting process. In order to simulate the flow / The finite element numerical analysis method of fluid flow that can realize precise and sophisticated finite element model is presented. The finite element numerical analysis method of fluid flow is composed of steps of constituting grid network in fluid flow region, And reconstructing the lattice network based on the reconstructed lattice network. According to the finite element numerical analysis method of the fluid flow, when a dry element appears Due to the reduction of the applied grid, the number of equations is reduced, so it can be simulated more quickly and the wrinkling / wetting phenomenon There is an effect that can be practically expressed.

However, the conventional method includes a step of analyzing fluid flow information through a lattice network reconstruction by a factor elimination technique among the wiping / wetting techniques that have been used in the prior art. However, By using the critical depth water depth technique, which is a form of technique, the discontinuity of the boundary surface is prevented.

Korean Patent Publication No. 10-2011-0130821 (Published on Dec. 2011), entitled "Finite Element Numerical Analysis Method of Fluid Flow Using Rake / Wet Treatment"

Previous studies have predicted the water level in advance and then performed a simulation by removing the topographic grid corresponding to the boundary or island corresponding to the highland site. Therefore, it is necessary to newly reconstruct the grid constructed at the time of changing the boundary conditions such as flow rate and water level There were disadvantages. In addition, there was also a problem of preserving the mass according to the movement of the water quantity. On the other hand, in the method of simulating the terrain as a permeable layer like a swamp, the bottom friction term is likely to diverge due to the characteristics of the shallow water equation, and a negative value is generated in the water depth treatment, Was raised. Especially, in the case of the steep slope area and the area where the tide change was large, this situation frequently occurred and further effort was required in the model construction.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an apparatus and method for constructing a model of a shallow water equation, in which it is not necessary to generate a new grid according to a boundary condition and a specific simulation idea, The present invention is to provide a method for analyzing a two-dimensional water flow through the application of a water / wet condition by using a critical water depth technique, which can solve the problem of divergence in a dry area and obtain high stability.

It is another object of the present invention to provide a method and apparatus for controlling a problem of a discontinuous interface and capable of preventing the occurrence of an intrinsic velocity in a dry area or an abnormal depth simulation result, The present invention provides a method of analyzing a two-dimensional water flow through the application of a condition of dry / wet using a critical water depth method.

(A) a bottom friction coefficient (f), a turbulent tie point coefficient (v), a roughness coefficient (n), a topographic data , The simulated end time (t _f ), the critical dry depth (h _dry ), and the boundary condition (flow rate, water level) are input to the main memory as input data. Comparing with the critical dry depth (h _dry );

)의 값도 0으로 부여하는 단계와;(b) the central processing unit judges that a blurring phenomenon has occurred at a node where the water depth value is smaller than the critical dry water depth (h _dry ) in the step (a), and the vertical water depth average velocity (u) The value of the depth-averaged velocity (v) is given as 0, the depth value of the node is assigned as critical dry depth (h _dry )

) To a value of 0;

(c) The central processing unit calculates the longitudinal water depth average velocity (u) value, transverse water depth average velocity (v) value, and water depth value in the step (a) (U, v) at the arbitrary time (t) by using a program in the main memory, which is a numerical model applied to the value of the water depth (DGT) (U, v, h) by calculating the water depth (h) and the water depth

(d) The central processing unit compares the value of the depth h at each node of the lattice network calculated in the step (c) with the critical depth of water (h _dry ) to determine the depth h (h) value is the critical diamond depth smaller joints than (h _dry) are assigned the value of the longitudinal depth of the average flow velocity (u) and the lateral depth of the average flow velocity (v) of zero and a depth (h) the value of that node is the critical diamond depth (h _dry ), and correcting the flow field length (u, v, h) at an arbitrary time (t).

Further, the present invention is characterized in that in the step (c), the mathematical expression for calculating the vertical and horizontal depth-averaged flow velocities (u, v) and the depth h

와

Wow

(Here, u _i and u _j are each i direction and the j direction of depth of the average flow rate, x _i and x _j are each i direction and the j direction of the length, t is the time, g is the acceleration of gravity, H is the distance to the charge image from the reference line , h is the depth of water, v is the turbulent kinematic constant, and n is the roughness factor representing the roughness of the bed and the wall surface).

Further, the present invention is characterized in that the central processing unit repeats the steps (b) to (d) at arbitrary time intervals before the simulation end time (t _f ).

In the present invention, when a change of a boundary condition (flow rate, water level) according to a time flow in a corresponding area for analyzing a two-dimensional water flow is input to the main memory as input data, And the water level in the step (a) are changed according to the modification of the boundary conditions (flow rate, water level).

The method of analyzing the two-dimensional flow of water through the application of the spraying / wetting condition using the critical declining water depth method of the present invention as described above requires that a new lattice is generated according to the boundary condition and the specific simulation thought , It is possible to solve the divergence problem mainly occurring in the existing model and to obtain the high stability result and to control the problem of the discontinuous boundary surface and to prevent the occurrence of the intrinsic velocity in the dry area or the abnormal depth simulation result Therefore, it is possible to perform the analysis of the shallow water flow more stably and efficiently.

1 is a view showing a kind of a drying / wetting technique.
Fig. 2 is a conceptual diagram of a critical declining water depth technique; Fig.
Fig. 3 is a view for solving a problem in accordance with the application of a critical declination depth. Fig.
4 is a flowchart showing a method of applying a dry / wet condition using the concept of critical dry depth.
5 is a diagram showing boundary conditions for numerical simulation of a linear bottom slope area.
Fig. 6 is a diagram showing numerical simulation results of a linear bottom slope region based on the concept of critical declining water depth. Fig.
7 shows a cone-shaped island region simulated region and a boundary condition.
FIG. 8 is a diagram showing a numerical simulation result of a cone-shaped island region by the critical declination depth method. FIG.
9 is a view showing a natural river simulation region and a bottom level.
10 is a view showing a boundary condition for simulating a natural river;
11 is a view showing a depth distribution of a natural river over time.
12 is a view showing a variation of the depth distribution in the islands by applying the critical declination depth method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The normal smoothing / wetting algorithm can be classified into four types as shown in FIG. The first is to apply all the nodes and elements to the numerical calculations by applying the critical edge depth method or the thin film method as the simulated region in the side or upstream and downstream interface regions. Generally, the minimum reference depth (threshold depth) is set in the simulation, and the area where the joint point falls below the reference depth is simulated as if the thin membrane is unfolded. In this case, it is possible to solve the discontinuity problem of the interface due to sudden change of the water depth occurring in the element removal technique to zero. The present invention is an improvement of the critical declination depth method. In the present invention, since the critical declination depth method fixes the lattice by the Eulerian method, it can reduce the inconvenience of the lattice reconstruction and completely exclude the element from the computation area. Discontinuity can be prevented. Further, in the present invention, when the water depth of a specific node falls below a reference value at the time of numerical calculation by setting the critical water depth before the numerical simulation, the water depth at the node is given as a critical water depth and the flow rate is set to zero. In order to block the instability caused by the unsteady wave generated at the dry / wet interface, flow flux blocking technique is used which gives the water depth of the nodal momentum equation of the nod to zero. And floor friction coefficient is used to solve the problem of divergence of bottom friction.

The second method, the element removal method, is to determine whether the element is dry by model and then exclude the element from the computation area at the time of simulation. Unlike the above method, which intercepts the fluidity of the flow, the boundary is newly defined every time and the simulation is executed. TELEMAC, EFDC, MIKE21, etc., have used this technique and have a merit that the blinking interval is definitely defined, but there is a disadvantage in that the probability of divergence increases in the calculation due to the discontinuity problem at the interface.

In the third depth extrapolation technique, water depth is extrapolated from the element corresponding to the wetting at the water interface where the wetting / wetting occurs. It is important to distinguish the position of the first interface at the simulation, and the element is activated by conditional activation to include a part of the dry area in the round border.

The fourth negative depth technique assumes that there is a permeable layer at the bottom of the simulated section and considers that the water flow is applied to this permeable layer. Using this technique, the presence of a permeable layer can cause the surface of the water body to go down below the topographic data, resulting in negative water depths. This technique was used in RMA2 and RIVER-2D. In past research, water flow was classified as one kind of thin film technique because it existed all the way. It has the advantage of conservation of mass and momentum after calculation and shows good results when simulation of tide near swamp area. However, the assumption that the bottom of the simulated section always has iso-permeability, such as having a constant permeability coefficient, is physically unsuitable and poses a problem in applicability.

Critical water depth  Analysis of Wrinkle / Wetting by Technique

The concept of the critical declination depth method used in the present invention is to set a specific boundary value h _dry for the depth of water as shown in FIG. 2, and to set the critical declination depth h _{dry at a} node or region having a shallower depth than the boundary value And by assigning the flow velocity value of the nodal point or region to 0, it is a technique to effectively simulate the drying / wetting phenomenon. Therefore, it is also referred to as a point treatment, a thin film technique, or a flux blocking method. The range of the critical declination water depth varies depending on the river or the coast, but generally values of several centimeters to several millimeters are input.

The momentum equation in the two-dimensional shear water equation for analyzing the flow behavior of the surface water where the wrinkling / wetting phenomenon occurs is represented by the following Equation 1, and the continuity equation is expressed by Equation 2 below.

Here, u _i and u _j are the i-direction and j-direction depth averaged flow velocities, x _i and x _j are respectively the i and j direction lengths, t is time, g is gravitational acceleration, H is distance from baseline to bed, h is the depth of water, v is the turbulent kinematic constant, and n is the roughness factor representing the roughness of the bed and wall.

For reference, the equations (1) and (2) are expressed by a tensor notation method and are expressed by expressions excluding dimensions in order to explain the relation with vectors.

를 도입한 다음의 수학식 3과 같은 운동량 방정식을 적용한다.The last term of the right side of Equation (1) is a term relating to the bottom friction. Since the depth variable (h) is included in the denominator and the shallow critical depth water depth value of several millimeters is input, It becomes too large compared to the other term, and the solution can be diverted. Therefore, in the present invention,

And the momentum equations of Equation (3) below are applied.

)의 급격한 변화에 의해 가상의 파가 형성되어 비정상적인 유속 및 수심 결과가 나타나게 된다. 따라서 본 발명에서는 마름이 발생한 절점 및 영역의 수심 경사항을 0의 값으로 구속하는 조건을 추가적으로 부여한다.When simulating the phenomenon of dryness / wetting by using the above-mentioned threshold water depth concept and the momentum equation incorporating the bottom friction coefficient, as shown in FIG. 3, the water is physically blotted and forced to the critical water depth region (DGT, DGT, and DGT) at the boundary of the wet /

), A virtual wave is formed, resulting in an abnormal flow velocity and a water depth result. Therefore, in the present invention, a condition for restricting the depth of the nodal point and the area where the nodule is formed to a value of 0 is additionally given.

On the other hand, the Chuncheon equation is a partial differential equation expressing the horizontal flow of a natural river. It has analytical solution under specific boundary condition and flow condition, but analysis of flow behavior using analytical solution is very limited. Therefore, there are various numerical methods to obtain approximate solutions. Among them, the finite element method is relatively advantageous in a complex stream boundary because the adoption of an unstructured grid combining a triangle or a square is free. In addition, using the adaptive mesh, it is possible to optimize the grid size, segment score, and solution accuracy. In addition, it is very straightforward and easy to apply to various Neumann boundary conditions, and it is a numerical technique based on a solid mathematical foundation. Therefore, it is also possible to perform mathematical analysis on error, convergence, and solution accuracy. Accordingly, in the present invention, a method of interpreting a finite element model by applying it to a shallow water equation will be adopted in order to accurately and effectively analyze the water flow generated in a natural water body such as a river or a coast.

FIG. 4 is a flow chart showing a method for effectively simulating the drying / wetting phenomenon in the above two-dimensional hydrodynamic flow analysis model. Enter the simulated conditions, such parameters including the ground friction coefficient (f) for using a shallow water equations to interpret the diamond / wetting phenomenon variables, simulation end time (t _f) and the critical diamond depth (h _dry), and the shallow water flow Assign initial and boundary conditions to interpret the problem. If the water depth at each node is smaller than the critical dry depth (h _dry ), it is assumed that dryness has occurred and the vertical flow velocity (u) and transverse flow velocity (v) h _dry and the value of the water depth (DGT) is also assigned as 0. (U, v) and depth (h) at each node at time t, calculate the flow field at all nodes (NODES), and then calculate the flow field The water depth at each node is compared with the critical depth of water and the flow field at time t is corrected and output, and the flow rate field at a specific time is obtained by repeating the same method until the simulation end time (t _f ).

First, the bottom friction coefficient (f), the turbulent tie point coefficient (υ), the roughness coefficient (n), the topographic data, the simulation end time (t _f ) (h _dry ) and boundary conditions (flow rate, water level) are inputted into the main memory as input data, and the central processing unit of the numerical simulation compares the water depth value at the grid node to the critical water depth (h _dry ) (step a).

)의 값도 0으로 부여하게 된다(b 단계).Next, in the step (a), it is determined that a central phenomenon occurs in the node where the water depth value is less than the critical dry depth (h _dry ), and the vertical direction water depth average velocity (u) The value of the depth-averaged velocity (v) is given as 0, the depth value of the node is assigned as critical dry depth (h _dry )

) Is also given as 0 (step b).

Next, the central processing unit determines the input data in step (a) and the value of the longitudinal direction average velocity (u), transverse direction average velocity (v) in the step (b) (DGT) and the finite element method are applied to the above equations (1) and (2), and at the arbitrary time (t) using a program in the main memory, which is numerically modeled, the vertical and horizontal depth- u, v) and the water depth (h) are calculated to obtain the flow field length (u, v, h) (step c).

Finally, the central processing unit compares the value of the depth h at each node of the lattice network calculated in the step (c) with the critical depth of water depth (h _dry ) to calculate the depth h (h) value is the critical diamond depth smaller joints than (h _dry) are assigned the value of the longitudinal depth of the average flow velocity (u) and the lateral depth of the average flow velocity (v) of zero and a depth (h) the value of that node is the critical diamond depth (h _dry ) to correct the flow field length (u, v, h) at an arbitrary time (t) (step d).

Here, the execution of the steps of the process and the numerical model are programs in which algorithms are directly coded through a programming language to be finally executed by a computer, and these programs are stored in the main memory of the computer including the equations (1) and The central processing unit of the computer calculates the flow field (u, v, h) at an arbitrary time and position by using the input data input to the main memory by the input device and the program.

Also, it the CPU is before simulation end time (t _f) a step of repeating by a random time interval between the steps (b) to the step (d) can be added, and here too, the performance of this process it to a computer This is done by a program that directly codes the algorithm through the programming language to perform.

In addition, when the boundary conditions (flow rate, water level) are input to the main memory as the input data, the boundary condition (flow rate, water level) And the water depth value in the step (a) is also changed according to the modification of the boundary condition (flow rate, water level).

Applying the Wrinkle / Wetting Analysis Model

The simulation / wetting analysis model developed by the present invention was applied to the following three areas to analyze simulation performance in natural rivers including artificial underground, virtual two dimensional area and islands.

(1) Linear bed slope area

As shown in Fig. 6, the initial condition was given to the area where the elevation of the bed elevation changes linearly from 0 to 10. After that, the water level at x = 25,000 m is raised for 6 hours as shown in Fig. 5, and then symmetrically lowered, and the simulation conditions are set so that the drying and wetting phenomenon appears sequentially for 12 hours in the simulation region . Considering the length of the simulated area and the variation range of the depth of water, the critical depth of water was set to h _dry = 5 cm, and simulated conditions and parameters were entered as t _f = 12 hr, f = 0.01. As a result of the numerical simulation using the algorithm of FIG. 4, as shown in FIG. 6, the wetting area was up to 5 km according to the rising free surface condition after 1.2 hr. At 3 hr, the wetting area was up to 15 km due to the rising water level up to 7 m. After that, the wetting phenomenon occurred again with the falling boundary condition. In the simulation end time t _f = 12 hr, most of the area was changed to the dry state by the low water condition. It is confirmed that the phenomenon is reproduced well.

(2) Conical island region

As shown in Fig. 0 m to El. Conical island areas varying up to 0.5 m are constructed and the water level is changed to El. From 0.6 m to El. Numerical simulation conditions were set up so that the blinking occurs in some sections of the conical islands from 200 seconds after the start of simulation. Considering the size of the imaginary channel and the variation of the depth of water, the critical depth of water was set to h _dry = 1 cm, and the simulated conditions and parameters were entered as t _f = 1,000 sec., F = 0.01. FIG. 8 shows the distribution of the depth of water according to the time, and the region where the blotting occurs is shown as a margin. As shown in Fig. 8 (a), at t = 440 sec. And the radial area including the highest point of the cone-shaped island is given by 0.4 m or less. In FIG. 8 (b), the water level condition is El. And it was found that the blistering occurred in a wider area. Therefore, it is understood that the blurring / wetting analysis technique utilizing the floor friction coefficient introduced in the present invention and the momentum equation based on the critical declining water depth concept and the water depth constraint well simulate the blotting phenomenon in the two-dimensional simulation region .

(3) Natural rivers

In order to examine whether the spraying / wetting analysis technique based on the critical declining water depth concept proposed in the present invention is well applied to natural rivers including islands, numerical simulations are carried out by selecting the section of the Han River Jungnangcheon confluence part and the Anyangcheon confluence part as shown in FIG. Respectively. The river floor height including the three load diagrams (Nodle Island, Bam Island, -9 m to El. The topographic file was varied up to +4 m. As shown in FIG. 10, the flow rate of about 3,800 to 6,600 tons per second flows into the confluence of Jungnangcheon in the boundary conditions. From 4.5 m to El. 5.4 m. Therefore, the water level at the boundaries of the Anyang Stream merged by the boundary conditions and bed bottom condition is El. From 12 hours lower than 4.9 m, blotting phenomenon appeared in three islands. Considering the variation of the depth of the natural river, the critical dry depth was set to h _dry = 5 cm, and simulated conditions and parameters were entered at t _f = 16 hr, f = 0.05.

11 shows the distribution of water depths after 5 hr and 16 hr with the largest and smallest water level boundary conditions input at the confluence part of Anyang Stream. After 5 hr of simulation, as shown in FIG. 11 (a), the water depths in the three islands are about 50 cm and the entire simulation region has a higher water depth than the critical water depth. However, the water level has been steadily decreasing. At 16 hr lowered to 4.5 m, three islands were blotted as shown in Fig. 11 (b), resulting in a depth of 5 cm corresponding to the critical depth of water. The simulation results above can be more clearly seen in FIG. 12, which shows the distribution of water depths over time in three islands.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. You will be able to make various changes without departing.

Claims (4)

(a) the floor friction coefficient (f), the turbulent tie point coefficient (v), the roughness coefficient (n), the terrain data, the simulated end time (t _f ) (h _dry ) and boundary condition (flow rate, water level) are input to the main memory as input data, and the whole central processing unit of the numerical simulation compares the water depth value at each grid node with the critical water depth (h _dry ) Wow;
(b) the central processing unit judges that a blurring phenomenon has occurred at a node where the water depth value is smaller than the critical dry water depth (h _dry ) in the step (a), and the vertical water depth average velocity (u) The value of the depth-averaged velocity (v) is given as 0, the depth value of the node is assigned as critical dry depth (h _dry )

) To a value of 0;
(c) The central processing unit calculates the longitudinal water depth average velocity (u) value, transverse depth water velocity (v) value, and water depth value in the step (a) (U, v) at the arbitrary time (t) by using a program in the main memory, which is a numerical model applied to the value of the water depth (DGT) (U, v, h) by calculating the water depth (h) and the water depth
(d) The central processing unit compares the value of the depth h at each node of the lattice network calculated in the step (c) with the critical depth of water (h _dry ) to determine the depth h (h) value is the critical diamond depth smaller joints than (h _dry) are assigned the value of the longitudinal depth of the average flow velocity (u) and the lateral depth of the average flow velocity (v) of zero and a depth (h) the value of that node is the critical diamond depth (h _dry) assigned to chapter flow rate at any time (t) (u, v, h) a through grant of using the critical diamond depth techniques, characterized in that comprising the step of modifying diamond / wet conditions, the two-dimensional How to interpret the flow of water.
The method according to claim 1,
In the step (c), the mathematical expression for calculating the vertical and horizontal depth-averaged flow velocities (u, v) and the depth of water (h)

Wow

(Here, u _i and u _j are each i direction and the j direction of depth of the average flow rate, x _i and x _j are each i direction and the j direction of the length, t is the time, g is the acceleration of gravity, H is the distance to the charge image from the reference line , h is the depth of water, v is the turbulent kinematic constant, and n is the roughness coefficient representing the degree of roughness of the bed and the wall surface.) By using the critical depth water depth technique, Lt; / RTI >
The method according to claim 1,
(b) repeating the steps (b) to (d) at arbitrary time intervals before the central processing unit completes the simulation end time (t _f ). A method of interpreting a two-dimensional flow of water through the application of spin / wet conditions.
The method of claim 3,
When the change of the boundary condition (flow rate, water level) according to the time flow in the region interpreting the two-dimensional water flow is input to the main memory as the input data, the boundary condition (flow rate, And the water depth value in the step (a) is also changed according to the modification of the boundary conditions (flow rate, water level), and the two-dimensional water flow is analyzed through the application of the water / wet condition by using the critical water depth method How to.

Images