CN113158324A - Method for determining main parameters of ship water jet propeller - Google Patents

Method for determining main parameters of ship water jet propeller Download PDF

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CN113158324A
CN113158324A CN202110031355.7A CN202110031355A CN113158324A CN 113158324 A CN113158324 A CN 113158324A CN 202110031355 A CN202110031355 A CN 202110031355A CN 113158324 A CN113158324 A CN 113158324A
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assumed
value
ship
speed ratios
speed
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CN113158324B (en
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周鹏程
毛季
程文池
胡彬彬
李森
张小波
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Wuhan Marine Machinery Plant Co Ltd
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Wuhan Marine Machinery Plant Co Ltd
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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/15—Vehicle, aircraft or watercraft design
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B71/00—Designing vessels; Predicting their performance
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/17—Mechanical parametric or variational design
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/20—Design optimisation, verification or simulation
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
    • G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation

Abstract

The disclosure provides a method for determining main parameters of a ship water-jet propeller, and belongs to the technical field of underwater propulsion. The determination method comprises the following steps: determining the influence factor, and determining the assumed value of the influence factor; obtaining an assumed value of a main parameter of the ship water-jet propeller according to a water-jet propulsion theory and the assumed value of the influence factor; based on the assumed value of the main parameter, correcting the assumed value of the influence factor to obtain a corrected value of the influence factor; based on the correction of the influence factors, correcting the assumed value of the main parameter to obtain a corrected value of the main parameter; continuously iteratively correcting the correction value of the main parameter and the correction value of the influence factor until the correction value of the main parameter is within a set value range; and taking the corrected value of the main parameter in the set numerical range as the design main parameter of the ship water jet propeller. The method can improve the precision of the main parameters.

Description

Method for determining main parameters of ship water jet propeller
Technical Field
The disclosure belongs to the technical field of underwater propulsion, and particularly relates to a method for determining main parameters of a ship water-jet propeller.
Background
The water jet propeller belongs to a reaction force propeller, and the incoming water flows through an inflow pipeline, and after passing through a propulsion pump (namely an energy conversion mechanism), the lift of water flow is increased, and after being accelerated by a nozzle, the water flow is jetted from the stern at a certain speed, and the reaction force generated by the water flow is used as the forward power of a ship.
In the related art, when designing a water jet propeller of a high-speed ship, main parameters of the water jet propeller are generally determined by using parameters of a mother ship or an existing empirical method, and the main parameters generally include flow, lift, specific rotation speed and cavitation specific rotation speed.
However, the main parameters of the water jet propeller obtained by the above method are obtained by correcting the main parameters of the existing ship type without considering other influencing factors of the actual water jet propeller, so that the difference between the obtained main parameters and the actual situation is large, and the product performance cannot meet the requirements of actual working conditions.
Disclosure of Invention
The embodiment of the disclosure provides a method for determining a main parameter of a ship water-jet propeller, which can improve the accuracy of the main parameter of the ship water-jet propeller.
The technical scheme is as follows:
the embodiment of the disclosure provides a method for determining main parameters of a ship water jet propeller, which comprises the following steps:
determining the influence factors, wherein the influence factors comprise an inflow pipeline loss coefficient, an influence coefficient of a boundary layer on the flow quantity of the inlet water and an influence coefficient of the boundary layer on the flow energy of the inlet water;
determining a hypothetical value for the impact factor;
obtaining an assumed value of main parameters of the ship water-jet propeller according to a water-jet propulsion theory and the assumed value of the influence factor, wherein the main parameters comprise flow, lift, specific rotating speed and cavitation specific rotating speed;
based on the assumed value of the main parameter, correcting the assumed value of the influence factor to obtain a corrected value of the influence factor;
based on the correction value of the influence factor, correcting the assumed value of the main parameter to obtain the correction value of the main parameter;
continuously iteratively correcting the correction value of the main parameter and the correction value of the influence factor until the correction value of the main parameter is within a set value range;
and taking the corrected value of the main parameter in the set numerical value range as the design main parameter of the ship water jet propeller.
In another implementation manner of the present disclosure, the obtaining the assumed value of the main parameter of the ship water jet propeller according to the water jet propulsion theory and the assumed value of the influence factor includes:
obtaining a relation curve of propulsion efficiency and a speed ratio according to a water jet propulsion theory and the assumed value of the influence factor, wherein the speed ratio is the ratio of the nozzle speed of the propeller to the ship speed;
determining a plurality of speed ratios based on the peak value of the relation curve, and obtaining a plurality of propulsion efficiencies corresponding to the plurality of speed ratios;
obtaining a plurality of assumed values of the main parameter based on a plurality of propulsion efficiencies corresponding to the plurality of speed ratios.
In another implementation manner of the present disclosure, the obtaining a plurality of assumed values of the main parameter according to a plurality of propulsion efficiencies corresponding to the plurality of speed ratios includes:
calculating to obtain a plurality of assumed values of ship thrust based on a plurality of propulsion efficiencies corresponding to the plurality of speed ratios;
based on a plurality of assumed values of the ship thrust, combining a ship resistance curve to obtain a plurality of assumed values of the ship speed;
obtaining assumed values of the flow rates of a plurality of ship nozzles based on the determined assumed values of the speed ratios and the ship speeds of the plurality of ships;
obtaining assumed values of a plurality of nozzle diameters based on the assumed values of the plurality of speed ratios and the plurality of influence factors;
and calculating to obtain the assumed values of the main parameters corresponding to the speed ratios based on the assumed values of the flow velocity of the plurality of ship nozzles and the assumed values of the diameters of the plurality of nozzles.
In another implementation manner of the present disclosure, the calculating a plurality of assumed values of ship thrust based on a plurality of propulsion efficiencies corresponding to the plurality of speed ratios includes:
calculating a plurality of assumed values of the ship thrust by the following formula;
Figure BDA0002892287030000031
wherein, TiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of ship thrusts; ne is rated input power, KW, of the ship water jet propeller; eta0The pump effect is achieved; etamMechanical loss of efficiency; etaciFor a plurality of speed ratios kiCorresponding propulsion system efficiency, V0iFor a plurality of speed ratios kiAnd correspondingly, assuming a plurality of ship speeds.
In another implementation manner of the present disclosure, the obtaining the assumed values of the plurality of ship jet flow velocities based on the determined plurality of speed ratios and the plurality of assumed values of the ship speed includes:
calculating to obtain a plurality of assumed values of the flow velocity of the ship nozzles through the following formula;
Vji＝Voi·ki；
wherein, V0iFor a plurality of speed ratios kiCorresponding multiple ship speed assumed values; vjiFor a plurality of speed ratios kiAnd (4) corresponding assumed value of the flow velocity of the ship nozzle.
In another implementation manner of the present disclosure, the obtaining assumed values of a plurality of nozzle diameters based on the assumed values of the plurality of speed ratios and the plurality of influence factors includes:
calculating an assumed value of the diameter of the nozzle by the following formula;
Figure BDA0002892287030000032
wherein D isjiMultiple speed ratios kiA corresponding plurality of assumed nozzle diameters; ne is rated input power, KW, of the ship water jet propeller; eta0The pump effect is achieved; vjiFor a plurality of speed ratios kiCorresponding assumed value of the flow velocity of the ship nozzle; k is an assumed value of the loss coefficient of the inflow pipeline; beta is the influence coefficient of the boundary layer on the flow energy of the inlet water; v0iFor a plurality of speed ratios kiAnd (4) corresponding ship speed assumed value.
In another implementation manner of the present disclosure, the calculating, based on a plurality of assumed values of the ship nozzle flow velocity and a plurality of assumed values of the nozzle diameter, assumed values of a plurality of main parameters corresponding to the plurality of speed ratios includes:
calculating the assumed value of the flow, wherein the assumed value of the flow is calculated by the following formula:
Figure BDA0002892287030000033
wherein Q isiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; vjiFor a plurality of speed ratios kiCorresponding assumed value of the flow velocity of the ship nozzle; djiFor a plurality of speed ratios kiA corresponding plurality of assumed nozzle diameters;
calculating the assumed value of the lift, wherein the assumed value of the lift is calculated by the following formula:
Hi＝Neη0/Qi；
wherein HiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of lifts; ne is the rated input power of the ship water jet propeller; eta0The pump effect is achieved; qiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows;
calculating the assumed value of the specific rotating speed, wherein the assumed value of the specific rotating speed is calculated by the following formula:
Figure BDA0002892287030000041
wherein n issiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of specific rotation speeds; hiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of lifts; qiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; n is the speed ratio kiThe corresponding number;
calculating an assumed value of the cavitation ratio rotating speed, wherein the assumed value of the cavitation ratio rotating speed is calculated by the following formula:
Figure BDA0002892287030000042
wherein, csiIs an assumed value of cavitation specific rotating speed; qiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; n is the speed ratio kiThe corresponding number; v0iFor a plurality of speed ratios kiA corresponding ship speed assumed value; beta is the influence coefficient of the boundary layer on the flow energy of the inlet water; h iscThe installation height of the ship water jet propeller.
In another implementation manner of the present disclosure, the modifying the assumed value of the impact factor based on the assumed value of the main parameter to obtain a modified value of the impact factor includes:
determining impeller parameters of the ship water jet propeller according to the assumed value of the main parameter, wherein the impeller parameters comprise the type of an impeller, the number of blades, the diameter of an impeller hub and the diameter of an impeller excircle;
obtaining a correction value of the loss coefficient of the inflow pipeline according to the assumed value of the flow and the impeller parameter;
and obtaining the correction value of the influence coefficient of the boundary layer on the flow quantity of the inlet water and the correction value of the influence coefficient of the boundary layer on the flow energy of the inlet water according to a boundary layer theoretical formula and the flow velocity distribution of the fluid boundary layer.
In another implementation manner of the present disclosure, the obtaining a corrected value of an inflow pipe loss coefficient according to the assumed value of the flow rate and the impeller parameter includes:
calculating to obtain pipeline loss parameters according to the impeller parameters, the assumed values of the cavitation specific rotating speed and the assumed values of the specific rotating speed, wherein the pipeline loss parameters comprise inlet loss, grid loss, nozzle contraction loss and appendage loss;
and calculating to obtain the corrected values of the loss coefficients of the inflow pipelines according to the pipeline loss parameters and a plurality of ship navigational speed assumed values corresponding to the speed ratios.
In another implementation manner of the present disclosure, the calculating a plurality of corrected values of the inflow pipeline loss coefficients according to the pipeline loss parameter and a plurality of assumed ship speed values corresponding to the plurality of speed ratios includes:
calculating a corrected value of the loss coefficient of the inflow pipeline by the following formula;
Figure BDA0002892287030000051
wherein, KiFor a plurality of speed ratios kiA plurality of corresponding corrected pipeline loss coefficients; Δ hiiFor a plurality of speed ratios kiCorresponding inlet losses; Δ hgiFor a plurality of speed ratios kiCorresponding grid losses; Δ hsiFor a plurality of speed ratios kiThe corresponding nozzle shrinkage loss; Δ hfiAt a plurality of speedsRatio kiCorresponding appendage losses.
The technical scheme provided by the embodiment of the disclosure has the following beneficial effects:
when the propeller is designed by the method for determining the main parameters of the ship water jet propeller, influence factors are assumed according to empirical parameters, so that the assumed values of the influence factors of the propeller can be obtained according to experience or existing data.
Then, according to the assumed value of the influence factor and the water jet propulsion theory, different propulsion efficiencies corresponding to a plurality of different speed ratios can be correspondingly obtained. Then, with different propulsion efficiencies, the assumed values of the main parameters of the propeller can be calculated.
Then, the assumed value of the influence factor is corrected by using the assumed value of the main parameter to obtain a corrected value of the influence factor, and the assumed value of the main parameter is corrected by using the corrected value of the influence factor to obtain a corrected value of the main parameter. And finally, obtaining design main parameters through continuous iteration.
According to the method for determining the main parameters of the water jet propeller, the main parameters are obtained through the influence factors, and the main parameters are continuously corrected, so that the influence factors on the efficiency of a propulsion system are considered when the main parameters are determined, the acting part (pump), the through-flow pipeline system and the ship body are considered as a whole to be researched, the main parameters are optimized, and the main parameters can better meet the actual conditions.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present disclosure, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive labor.
Fig. 1 is a flowchart of a method for determining main parameters of a marine water jet propeller according to an embodiment of the present disclosure;
fig. 2 is a flowchart of another method for determining main parameters of a marine water jet propeller according to an embodiment of the present disclosure.
Detailed Description
To make the objects, technical solutions and advantages of the present disclosure more apparent, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.
The embodiment of the disclosure provides a method for determining a main parameter of a ship water jet propeller, as shown in fig. 1, the method for determining the main parameter includes:
s101: determining influence factors, wherein the influence factors comprise an inflow pipeline loss coefficient, an influence coefficient of a boundary layer on the flow quantity of the inlet water and an influence coefficient of the boundary layer on the flow energy of the inlet water.
S102: the assumed value of the impact factor is determined.
S103: obtaining an assumed value of main parameters of the ship water-jet propeller according to a water-jet propulsion theory and an assumed value of an influence factor, wherein the main parameters comprise flow, lift, specific rotating speed and cavitation specific rotating speed;
s104: based on the assumed value of the main parameter, correcting the assumed value of the influence factor to obtain a corrected value of the influence factor;
s105: correcting the assumed value of the main parameter based on the corrected value of the influence factor to obtain the corrected value of the main parameter;
s106: continuously and iteratively correcting the correction value of the main parameter and the correction value of the influence factor until the correction value of the main parameter is within a set value range;
s107: and taking the corrected value of the main parameter in the set numerical range as the design main parameter of the ship water jet propeller.
When the propeller is designed by the method for determining the main parameters of the ship water jet propeller, influence factors are assumed according to empirical parameters, so that the assumed values of the influence factors of the propeller can be obtained according to experience or existing data.
Then, according to the assumed value of the influence factor and the water jet propulsion theory, different propulsion efficiencies corresponding to a plurality of different speed ratios can be correspondingly obtained. Then, with different propulsion efficiencies, the assumed values of the main parameters of the propeller can be calculated.
Then, the assumed value of the influence factor is corrected by using the assumed value of the main parameter to obtain a corrected value of the influence factor, and the assumed value of the main parameter is corrected by using the corrected value of the influence factor to obtain a corrected value of the main parameter. And finally, obtaining design main parameters through continuous iteration.
According to the method for determining the main parameters of the water jet propeller, the main parameters are obtained through the influence factors, and the main parameters are continuously corrected, so that the influence factors on the efficiency of a propulsion system are considered when the main parameters are determined, the acting part (pump), the through-flow pipeline system and the ship body are considered as a whole to be researched, the main parameters are optimized, and the main parameters can better meet the actual conditions.
Fig. 2 is a flowchart of another method for determining a main parameter of a marine water jet propeller, provided in an embodiment of the present disclosure, and with reference to fig. 2, the determining method includes:
s201: determining influence factors, wherein the influence factors comprise an inflow pipeline loss coefficient, an influence coefficient of a boundary layer on the flow quantity of the inlet water and an influence coefficient of the boundary layer on the flow energy of the inlet water.
S202: the assumed value of the impact factor is determined.
According to the empirical parameters, the influence factors are assumed to obtain assumed values of the influence factors, wherein the influence factors comprise K, alpha and beta; k is the loss coefficient of the inflow pipeline, alpha is the influence coefficient of the boundary layer on the flow momentum of the inlet water, and beta is the influence coefficient of the boundary layer on the flow energy of the inlet water.
In this embodiment, according to empirical parameters of existing similar ship-type water jet propulsion units, a K inflow pipeline loss coefficient, an influence coefficient of an alpha boundary layer on the flow momentum of the inlet water, and an influence coefficient of a beta boundary layer on the flow energy of the inlet water are assumed.
S203: and obtaining the assumed value of the main parameters of the ship water-jet propeller according to the water-jet propulsion theory and the assumed value of the influence factor, wherein the main parameters comprise flow, lift, specific rotating speed and cavitation specific rotating speed.
Step S203 is implemented by:
(1) and obtaining a relation curve of the propulsion efficiency and the speed ratio according to a water jet propulsion theory and the assumed value of the influence factor, wherein the speed ratio is the ratio of the nozzle speed of the propeller to the ship speed.
Illustratively, in this embodiment, η is derived according to the K-value method in the water jet propulsion theorycF (K, K) curve, where ηcTo propulsion system efficiency; k is an assumed value of the loss coefficient of the inflow pipeline; k is the speed ratio.
(2) Based on the peak value of the relationship curve, a plurality of speed ratios are determined, and a plurality of propulsion efficiencies corresponding to the plurality of speed ratios are obtained.
In the above implementation, the water jet propulsion theory (K-value method) is referred to, and η derived from the theoretical valuecF (K, K) curve, when K (given by step 1) is constant, at ηcN speed ratios are selected one time near the highest point of the curve, and each speed ratio is respectively recorded as ki(i is more than or equal to 1 and less than or equal to n), and the n propulsion efficiencies on the corresponding curves are respectively recorded as etaci。
(3) The assumed values of the main parameters are obtained according to a plurality of propulsion efficiencies corresponding to a plurality of speed ratios.
The step (3) is realized by the following steps:
and (3.1) calculating to obtain a plurality of assumed values of ship thrust based on a plurality of propulsion efficiencies corresponding to a plurality of speed ratios.
Exemplarily, a plurality of assumed values of the ship thrust are calculated by the following formula;
Figure BDA0002892287030000081
wherein, TiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of ship thrusts; ne is rated input power, KW, of the ship water jet propeller; eta0The pump effect is achieved; etamMechanical loss of efficiency; etaciFor a plurality of speed ratios kiCorresponding propulsion system efficiency, V0iFor a plurality of speed ratios kiAnd correspondingly, assuming a plurality of ship speeds.
And (3.2) obtaining a plurality of assumed values of the ship navigational speed based on the assumed values of the plurality of ship thrusts and by combining a ship resistance curve.
In the above implementation, let Ti＝Ri，RiIs a speed ratio kiFinding R on ship resistance curve corresponding to ship resistanceiCorresponding ship speed V0iThen speed ratio kiThe corresponding assumed value of the ship speed can be known.
And (3.3) obtaining the assumed values of the flow velocities of the plurality of ship nozzles based on the plurality of determined speed ratios and the assumed values of the plurality of ship speeds.
Calculating to obtain assumed values of the flow velocities of a plurality of ship nozzles through the following formula;
Vji＝V0i·ki； (2)
wherein, V0iFor a plurality of speed ratios kiCorresponding multiple ship speed assumed values; vjiFor a plurality of speed ratios kiAnd (4) corresponding assumed value of the flow velocity of the ship nozzle.
And (3.4) obtaining a plurality of assumed values of the nozzle diameter based on the plurality of speed ratios and the assumed values of the plurality of influence factors.
Calculating an assumed value of the diameter of the nozzle by the following formula;
Figure BDA0002892287030000082
wherein D isjiThe assumed values of the diameters of the plurality of nozzles corresponding to the plurality of speed ratios; n is a radical ofeRated input power, KW, of the ship water jet propeller; eta0The pump effect is achieved; vjiFor a plurality of speed ratios kiCorresponding assumed value of the flow velocity of the ship nozzle; k is an assumed value of the loss coefficient of the inflow pipeline; beta is the influence coefficient of the boundary layer on the flow energy of the inlet water; v0iFor a plurality of speed ratios kiAnd (4) corresponding ship speed assumed value.
And (3.5) calculating to obtain the assumed values of the main parameters corresponding to the speed ratios on the basis of the assumed values of the flow velocity of the plurality of ship nozzles and the assumed values of the diameters of the plurality of nozzles.
Calculating an assumed value of the flow, wherein the assumed value of the flow is calculated by the following formula:
Figure BDA0002892287030000091
wherein Q isiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; vjiFor a plurality of speed ratios kiCorresponding assumed value of the flow velocity of the ship nozzle; djiMultiple speed ratios kiA corresponding plurality of assumed nozzle diameters;
calculating an assumed value of the lift, wherein the assumed value of the lift is calculated by the following formula:
Hi＝Neη0/Qi； (5)
wherein HiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of lifts; ne is the rated input power of the ship water jet propeller; eta0The pump effect is achieved; qiFor a plurality of speed ratioski is a plurality of assumed values of the flow rate;
calculating a hypothetical value of the specific rotating speed, wherein the hypothetical value of the specific rotating speed is calculated by the following formula:
Figure BDA0002892287030000092
wherein n issiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of specific rotation speeds; hiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of lifts; qiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; n is the speed ratio kiThe corresponding number;
calculating an assumed value of the cavitation ratio rotating speed, wherein the assumed value of the cavitation ratio rotating speed is calculated by the following formula:
Figure BDA0002892287030000093
wherein, csiIs an assumed value of cavitation specific rotating speed; qiFor a plurality of speed ratios kiHypothetical values for a corresponding plurality of flows; n is the speed ratio kiThe corresponding number; v0iFor a plurality of speed ratios kiA corresponding ship speed assumed value; beta is the influence coefficient of the boundary layer on the flow energy of the inlet water; h iscMounting height for water jet propeller of ship
S204: and correcting the assumed value of the influence factor based on the assumed value of the main parameter to obtain a corrected value of the influence factor.
And (4.1) determining impeller parameters of the ship water-jet propeller according to the assumed values of the main parameters, wherein the impeller parameters comprise the type of an impeller, the number of blades, the diameter of an impeller hub and the diameter of an impeller excircle.
In the above implementation, n issi、csiThe type of impeller and the number of blades Z can be preliminarily selectediImpeller hub diameter DfiAnd the diameter D of the outer circle of the impellerri。
And (4.2) obtaining a corrected value of the loss coefficient of the inflow pipeline according to the assumed value of the flow and the impeller parameter.
Firstly, calculating to obtain pipeline loss parameters according to the impeller parameters, the assumed values of the cavitation specific rotating speed and the assumed values of the specific rotating speed, wherein the pipeline loss parameters comprise inlet loss, grid loss, nozzle contraction loss and attached body loss.
And then, calculating to obtain the corrected values of the loss coefficients of the inflow pipelines according to the pipeline loss parameters and a plurality of ship navigational speed assumed values corresponding to a plurality of speed ratios.
Illustratively, the corrected value of the loss coefficient of the inflow pipeline is calculated by the following formula;
Figure BDA0002892287030000101
wherein, KiIs a speed ratio kiThe corresponding corrected pipeline loss coefficient; Δ hiiIs lost as import; Δ hgiIs a grid loss; Δ hsiLoss of nozzle constriction; Δ hfiIs an appendage loss.
And (4.3) according to a boundary layer theoretical formula and the flow velocity distribution of the fluid boundary layer, obtaining the corrected value of the influence coefficient of the boundary layer on the flow momentum of the inlet water and the corrected value of the influence coefficient of the boundary layer on the flow energy of the inlet water.
Exemplarily, step (4.3) is implemented by:
(1) and determining the distance between the water inlet position of the water-jet propeller and the bow position and the ship speed of the water-jet propeller, and calculating the thickness of the boundary layer along the ship length direction according to the distance and the ship speed.
The distance between the water inlet of the propeller and the bow is l, the ship speed is V0iThe thickness of the boundary layer in the ship length direction is determined.
Obtaining the thickness of the boundary layer by the following formula;
δi＝f(l，Voi)； (9)
wherein, deltaiIs the boundary layer thickness; l is the distance between the water inlet of the propeller and the position of the bow, V0iIs the boat speed.
(2) And calculating the velocity distribution of the fluid in the boundary layer according to the theoretical formula of the boundary layer and the thickness of the boundary layer.
According to boundary layer thickness deltaiThe velocity profile of the fluid in the boundary layer is obtained.
The velocity profile of the fluid is formulated as follows:
Vyi＝f(δi，y)； (10)
wherein y is a coordinate perpendicular to the direction of the flow velocity measured from the hull, and the velocity V of the fluid outside the boundary layeryi＝V0i。
(3) And according to the flow velocity distribution of the fluid boundary layer, obtaining the corrected value of the influence coefficient of the boundary layer on the flow momentum of the inlet water and the corrected value of the influence coefficient of the boundary layer on the flow energy of the inlet water.
The actual input momentum and kinetic energy at the inlet can be obtained through the flow velocity distribution of the fluid boundary layer, and the influence factor can be obtained through the actual input energy.
The calculation formula is as follows:
Figure BDA0002892287030000103
Figure BDA0002892287030000104
wherein alpha isi、βiIs a speed ratio kiThe influence coefficient correction value of the corresponding inlet water flow momentum and the influence coefficient correction value of the boundary layer on the inlet water flow energy; a is the cross section of the inlet water flow.
S205: and obtaining a corrected value of the propulsion efficiency according to the water jet propulsion theory and the corrected value of the influence factor.
Step S205 is identical to the assumption of propulsion efficiency in step S203 in the value determination method, except that the assumed value of the influence factor is replaced with the previous correction value of the influence factor, and details are not repeated here.
S206: and obtaining the corrected value of the main parameter of the ship water-jet propeller according to the corrected value of the propulsion efficiency.
Step S206 is the same as step S204 except that the assumed value of the propulsion efficiency is replaced with the corrected value of the previous propulsion efficiency, which will not be described again here.
S207: and continuously and iteratively correcting the correction value of the main parameter and the correction value of the influence factor until the correction value of the main parameter is in a set value range.
S208: and taking the corrected value of the main parameter in the set numerical range as the design main parameter of the ship water jet propeller.
In the above implementation, K is continuously corrected by continuing to execute steps S205 and S206 on the corrected main parameteri、αi、βiThen the corrected K is again usedi、αi、βiUntil the design owner, the iterative calculation is repeatedWhen the change of the parameter is within a predetermined range, the selection of the main parameter is ended, and the final main parameter can be obtained.
The above description is meant to be illustrative of the principles of the present disclosure and not to be taken in a limiting sense, and any modifications, equivalents, improvements and the like that are within the spirit and scope of the present disclosure are intended to be included therein.

Claims (10)

1. A method for determining a principal parameter of a marine water jet, the method comprising:
determining the influence factors, wherein the influence factors comprise an inflow pipeline loss coefficient, an influence coefficient of a boundary layer on the flow quantity of the inlet water and an influence coefficient of the boundary layer on the flow energy of the inlet water;
determining a hypothetical value for the impact factor;
obtaining an assumed value of main parameters of the ship water-jet propeller according to a water-jet propulsion theory and the assumed value of the influence factor, wherein the main parameters comprise flow, lift, specific rotating speed and cavitation specific rotating speed;
based on the assumed value of the main parameter, correcting the assumed value of the influence factor to obtain a corrected value of the influence factor;
based on the correction value of the influence factor, correcting the assumed value of the main parameter to obtain the correction value of the main parameter;
continuously iteratively correcting the correction value of the main parameter and the correction value of the influence factor until the correction value of the main parameter is within a set value range;
and taking the corrected value of the main parameter in the set numerical value range as the design main parameter of the ship water jet propeller.
2. The method for determining the main parameter according to claim 1, wherein the obtaining the assumed value of the main parameter of the ship water jet propulsion unit according to the water jet propulsion theory and the assumed value of the influence factor comprises:
obtaining a relation curve of propulsion efficiency and a speed ratio according to a water jet propulsion theory and the assumed value of the influence factor, wherein the speed ratio is the ratio of the nozzle speed of the propeller to the ship speed;
determining a plurality of speed ratios based on the peak value of the relation curve, and obtaining a plurality of propulsion efficiencies corresponding to the plurality of speed ratios;
and obtaining a plurality of assumed values of the main parameter according to a plurality of propulsion efficiencies corresponding to the plurality of speed ratios.
3. The method of determining a primary parameter of claim 2, wherein said deriving a plurality of assumed values of the primary parameter based on a plurality of propulsion efficiencies corresponding to the plurality of speed ratios comprises:
calculating to obtain a plurality of assumed values of ship thrust based on a plurality of propulsion efficiencies corresponding to the plurality of speed ratios;
based on a plurality of assumed values of the ship thrust, combining a ship resistance curve to obtain a plurality of assumed values of the ship speed;
obtaining assumed values of a plurality of ship nozzle flow velocities based on the plurality of determined speed ratios and the plurality of assumed values of the ship speeds;
obtaining assumed values of a plurality of nozzle diameters based on the assumed values of the plurality of speed ratios and the plurality of influence factors;
and calculating to obtain the assumed values of the main parameters corresponding to the speed ratios based on the assumed values of the flow velocity of the plurality of ship nozzles and the assumed values of the diameters of the plurality of nozzles.
4. The method of determining a principal parameter of claim 3, wherein the calculating a plurality of hypothetical values of marine thrust based on a plurality of propulsion efficiencies corresponding to the plurality of speed ratios comprises:
calculating a plurality of assumed values of the ship thrust by the following formula;
Figure FDA0002892287020000021
wherein, TiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of ship thrusts; ne is rated input power, KW, of the ship water jet propeller; eta0The pump effect is achieved; etamMechanical loss of efficiency; etaciFor a plurality of speed ratios kiCorresponding propulsion system efficiency, V0iFor a plurality of speed ratios kiAnd correspondingly, assuming a plurality of ship speeds.
5. The method for determining the main parameter according to claim 3, wherein the obtaining a plurality of assumed values of the jet flow rate of the ship based on the plurality of speed ratios and the plurality of assumed values of the ship speed comprises:
calculating to obtain a plurality of assumed values of the flow velocity of the ship nozzles through the following formula;
Vji＝Voi·ki；
wherein, V0iFor a plurality of speed ratios kiCorresponding multiple ship speed assumed values; vjiFor a plurality of speed ratios kiAnd (4) corresponding assumed value of the flow velocity of the ship nozzle.
6. The method of determining a principal parameter of claim 3, wherein the deriving a plurality of assumed values of jet diameter based on the plurality of speed ratios and a plurality of assumed values of the impact factor comprises:
calculating an assumed value of the diameter of the nozzle by the following formula;
Figure FDA0002892287020000031
wherein D isjiMultiple speed ratios kiA corresponding plurality of assumed nozzle diameters; ne is rated input power, KW, of the ship water jet propeller; eta0The pump effect is achieved; vjiFor a plurality of speed ratios kiCorresponding assumed value of the flow velocity of the ship nozzle; k is an assumed value of the loss coefficient of the inflow pipeline; beta is boundary layer to inlet water flow energyThe influence coefficient of (a); v0iFor a plurality of speed ratios kiAnd (4) corresponding ship speed assumed value.
7. The method for determining the main parameters according to claim 3, wherein the calculating the assumed values of the main parameters corresponding to the speed ratios based on the assumed values of the flow velocity of the ship nozzle and the assumed values of the diameters of the nozzle comprises:
calculating the assumed value of the flow, wherein the assumed value of the flow is calculated by the following formula:
Figure FDA0002892287020000032
wherein Q isiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; vjiFor a plurality of speed ratios kiCorresponding assumed value of the flow velocity of the ship nozzle; djiFor a plurality of speed ratios kiA corresponding plurality of assumed nozzle diameters;
calculating the assumed value of the lift, wherein the assumed value of the lift is calculated by the following formula:
Hi＝Neη0/Qi；
wherein HiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of lifts; ne is the rated input power of the ship water jet propeller; eta0The pump effect is achieved; qiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows;
calculating the assumed value of the specific rotating speed, wherein the assumed value of the specific rotating speed is calculated by the following formula:
Figure FDA0002892287020000033
wherein n issiFor a plurality of speed ratios kiCorresponding assumed values of a plurality of specific rotation speeds; hiFor a plurality of speed ratios kiCorresponding toA hypothetical value for a plurality of lifts; qiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; n is the speed ratio kiThe corresponding number;
calculating an assumed value of the cavitation ratio rotating speed, wherein the assumed value of the cavitation ratio rotating speed is calculated by the following formula:
Figure FDA0002892287020000034
wherein, csiIs an assumed value of cavitation specific rotating speed; qiFor a plurality of speed ratios kiAssumed values of the corresponding plurality of flows; n is the speed ratio kiThe corresponding number; v0iFor a plurality of speed ratios kiA corresponding ship speed assumed value; beta is the influence coefficient of the boundary layer on the flow energy of the inlet water; h iscThe installation height of the ship water jet propeller.
8. The method for determining a main parameter according to claim 1, wherein the modifying the assumed value of the impact factor based on the assumed value of the main parameter to obtain a modified value of the impact factor comprises:
determining impeller parameters of the ship water-jet propeller according to the assumed value of the main parameter, wherein the impeller parameters comprise the type of an impeller, the number of blades, the diameter of a hub of the impeller and the diameter of an excircle of the impeller;
obtaining a corrected value of the loss coefficient of the inflow pipeline according to the assumed value of the flow and the impeller parameter;
and obtaining the corrected value of the influence coefficient of the boundary layer on the inlet water flow and the corrected value of the influence coefficient of the boundary layer on the inlet water flow according to the boundary layer theoretical formula and the flow velocity distribution of the fluid boundary layer.
9. The method for determining a principal parameter of claim 8, wherein the deriving a correction value for an inflow duct loss factor based on the assumed value of the flow rate and the impeller parameter comprises:
calculating to obtain pipeline loss parameters according to the impeller parameters, the assumed values of the cavitation specific rotating speed and the assumed values of the specific rotating speed, wherein the pipeline loss parameters comprise inlet loss, grid loss, nozzle contraction loss and appendage loss;
and calculating to obtain the corrected values of the loss coefficients of the inflow pipelines according to the pipeline loss parameters and a plurality of ship navigational speed assumed values corresponding to the speed ratios.
10. The method for determining the main parameter according to claim 9, wherein the calculating the correction values of the plurality of inflow duct loss coefficients according to the duct loss parameter and the plurality of assumed ship speed values corresponding to the plurality of speed ratios comprises:
calculating a corrected value of the loss coefficient of the inflow pipeline by the following formula;
Figure FDA0002892287020000041
wherein, KiFor a plurality of speed ratios kiA plurality of corresponding corrected pipeline loss coefficients; Δ hiiFor a plurality of speed ratios kiCorresponding inlet losses; Δ hgiFor a plurality of speed ratios kiCorresponding grid losses; Δ hsiFor a plurality of speed ratios kiCorresponding spout shrinkage loss; Δ hfiFor a plurality of speed ratios kiCorresponding appendage losses.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104112040A (en) * 2014-06-26 2014-10-22 中国人民解放军海军工程大学 Method for designing water-spraying boost pump hydraulic model for efficient and large-power-density ship
CN109063363A (en) * 2018-08-20 2018-12-21 北京理工大学 A kind of optimum design method of the hydraulic propeller based on database
CN109625226A (en) * 2018-11-27 2019-04-16 北京理工大学 A kind of axial-flow type high power density water jet propulsion pump design method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104112040A (en) * 2014-06-26 2014-10-22 中国人民解放军海军工程大学 Method for designing water-spraying boost pump hydraulic model for efficient and large-power-density ship
CN109063363A (en) * 2018-08-20 2018-12-21 北京理工大学 A kind of optimum design method of the hydraulic propeller based on database
CN109625226A (en) * 2018-11-27 2019-04-16 北京理工大学 A kind of axial-flow type high power density water jet propulsion pump design method

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
中国船舶工业集团公司，中国船舶重工集团公司，中国造船工程学会: "《船舶设计实用手册 总体分册》", 31 August 2013 *
王立祥: "船舶喷水推进", 《船舶》 *
金平仲: "喷水推进主要参数的确定", 《中国造船》 *

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