Coarse grid friction and heat flow calculation method, device, equipment and medium for water-gas two-phase flow

Abstract

The present application discloses a method, device, equipment and medium for calculating the coarse grid friction and heat flow of water-gas two-phase flow, and relates to the field of numerical simulation of water-gas two-phase flow, including: determining water and gas transport parameters based on the flow field parameters of the surface unit; the surface unit refers to the first layer of coarse grid on the surface of the object; using the grid Reynolds number determined based on the water and gas transport parameters and the preset wall function to determine the dimensionless velocity initial value and dimensionless wall distance initial value of the boundary layer; iteratively solving the preset wall function based on the Newton tangent method, the dimensionless velocity initial value and the dimensionless wall distance initial value until the target dimensionless velocity value and the target dimensionless wall distance value are determined when the conditions are met; based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, the target friction and heat flow value of the surface unit are determined to complete the numerical simulation operation of water-gas two-phase flow. The problem of wall rigidity of the turbulence model is effectively solved, and the calculation accuracy under the coarse grid is improved.

Description

Technical Field

[0001] The invention relates to the field of numerical simulation of water-gas two-phase flow, and in particular to a method, device, equipment and medium for calculating coarse grid friction and heat flow of water-gas two-phase flow. Background Art

[0002] At present, CFD (Computational Fluid Dynamics) technology is used in engineering applications. When performing numerical simulations of water-gas two-phase flows, the turbulence models all need to directly solve the variable gradient near the solid wall of the object, so the quality of the computational grid is very high. If the grid does not meet the requirements, the calculation accuracy may be reduced or even non-physical phenomena may occur. In order to meet practical applications, people have to pay a huge price for continuously encrypting the grid.

[0003] Taking the configuration of Dayun and Dake as an example, the amount of grids is basically more than 20 million. This brings a series of problems to the calculation: the aspect ratio of the normal near-wall grid is too large, which may be greater than 1000, seriously affecting the calculation accuracy and stability of the physical properties such as friction and heat flow of the grid; the grid volume is too small, limited by stability, and the local time step is very small, which seriously affects the calculation convergence speed and reduces the calculation benefit; and in optimization design, aeroelastic coupling calculation and other applications involving grid deformation reconstruction, the wall grid is too dense, which often leads to increased difficulty in grid reconstruction, reduced grid generation quality, and manual intervention is required, which reduces work efficiency.

[0004] Therefore, how to solve the wall rigidity problem of turbulence models to improve calculation accuracy and efficiency is an urgent problem to be solved. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a method, device, equipment and storage medium for calculating the coarse grid friction and heat flow of water-gas two-phase flow, which can effectively solve the problem of wall rigidity of turbulence model and improve the accuracy, efficiency and stability of friction and heat flow calculation under coarse grid, thereby greatly saving the input computing resources and human resources. The specific scheme is as follows:

[0006] In a first aspect, the present application provides a coarse grid friction and heat flow calculation method for water-gas two-phase flow, comprising:

[0007] Acquire flow field parameters of the object surface unit, and determine corresponding water transport parameters and gas transport parameters based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition;

[0008] Determine a grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter, and determine a dimensionless velocity initial value and a dimensionless wall distance initial value of a corresponding boundary layer using the grid Reynolds number and a preset wall function;

[0009] Iteratively solving the preset wall function based on the Newton tangent method, the dimensionless initial velocity value and the dimensionless initial wall distance value, until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met;

[0010] The target friction value and the target heat flux value corresponding to the object surface unit are determined based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, so as to complete the corresponding water-gas two-phase flow numerical simulation operation using the target friction value and the target heat flux value.

[0011] Optionally, the acquiring flow field parameters of the object surface unit and determining corresponding water transport parameters and gas transport parameters based on the flow field parameters include:

[0012] Obtaining flow field parameters of the object surface unit; the flow field parameters include corresponding density parameters, velocity parameters, pressure parameters, temperature parameters, gas mass fraction, gas volume fraction and laminar viscosity coefficient;

[0013] Determining a corresponding gas molecule viscosity coefficient based on the laminar viscosity coefficient, the temperature parameter and the Sutherland formula;

[0014] Determining the corresponding gas thermal conductivity coefficient, gas laminar flow Prandtl number, and gas constant-pressure specific heat based on the gas molecular viscosity coefficient and the flow field parameters;

[0015] Based on the flow field parameters and preset indicators, the corresponding liquid molecular viscosity coefficient, liquid thermal conductivity coefficient, liquid laminar flow Prandtl number, and liquid constant-pressure specific heat are determined.

[0016] Optionally, after determining the corresponding water transport parameters and gas transport parameters based on the flow field parameters, the method further includes:

[0017] Determining a corresponding mixed molecular viscosity coefficient based on the gas molecular viscosity coefficient, the first preset gas coefficient, the liquid molecular viscosity coefficient, and the first preset liquid coefficient;

[0018] determining a corresponding mixed heat transfer coefficient based on the gas heat transfer coefficient, the first preset gas coefficient, the liquid heat transfer coefficient, and the first preset liquid coefficient;

[0019] Determining a corresponding mixed laminar Prandtl number based on the gas laminar Prandtl number, the first preset gas coefficient, the liquid laminar Prandtl number, and the first preset liquid coefficient;

[0020] Determine a corresponding mixed constant-pressure specific heat based on the gas constant-pressure specific heat, the second preset gas coefficient, the liquid constant-pressure specific heat, and the second preset liquid coefficient;

[0021] The mixed molecular viscosity coefficient, the mixed heat conductivity coefficient, the mixed laminar flow Prandtl number and the mixed constant-pressure specific heat are used as transport parameters of the water-gas two-phase mixture.

[0022] Optionally, determining the grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter includes:

[0023] Determine the unit Reynolds number based on the sound velocity using the incoming flow density, incoming flow sound velocity and incoming flow laminar viscosity coefficient;

[0024] The grid Reynolds number corresponding to the object surface unit is determined by using the unit Reynolds number and the mixture transport parameter.

[0025] Optionally, the iteratively solving the preset wall function based on the Newton tangent method, the dimensionless initial velocity value, and the dimensionless initial wall distance value until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met, includes:

[0026] The dimensionless initial velocity value is updated by using a preset increment, and the preset wall function is iteratively solved based on the updated dimensionless initial velocity value, the Newton tangent method, and the dimensionless initial wall distance value until the dimensionless velocity value determined in the current iteration round meets the preset condition;

[0027] The dimensionless velocity value determined in the current iteration round is used as a target dimensionless velocity value, and a corresponding target dimensionless wall distance value is determined based on the grid Reynolds number and the target dimensionless velocity value.

[0028] Optionally, the determining of the dimensionless velocity initial value and the dimensionless wall distance initial value of the corresponding boundary layer by using the grid Reynolds number and a preset wall function includes:

[0029] Determine the dimensionless initial velocity value of the current boundary layer based on the Spalding velocity distribution formula and the grid Reynolds number;

[0030] Determine the current preset intermediate variable value by using the Clausius-Clapeyron equation, the dimensionless velocity initial value, and a preset intermediate variable formula corresponding to the preset wall function;

[0031] The dimensionless wall distance initial value of the current boundary layer is determined based on the preset intermediate variable value, the dimensionless velocity initial value and the preset wall function.

[0032] Optionally, determining a target friction value and a target heat flux value corresponding to the object surface unit based on the target dimensionless velocity value, the target dimensionless wall distance value, and the preset wall function includes:

[0033] Based on the target dimensionless velocity value, the target dimensionless wall distance value, the recovery factor, the wall temperature and the preset intermediate variable formula corresponding to the preset wall function, the corresponding wall shear stress value and the wall heat flux value are determined, so as to use the wall shear stress value and the wall heat flux value to solve the Navier-Stokes equations of the flow field, and complete the corresponding water-gas two-phase flow numerical simulation operation according to the obtained solution results.

[0034] In a second aspect, the present application provides a coarse grid friction and heat flow calculation device for water-gas two-phase flow, comprising:

[0035] A transport parameter determination module, used to obtain the flow field parameters of the object surface unit, and determine the corresponding water transport parameters and gas transport parameters based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition;

[0036] An initial value determination module, used to determine the grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter, and determine the dimensionless velocity initial value and the dimensionless wall distance initial value of the corresponding boundary layer by using the grid Reynolds number and a preset wall function;

[0037] An iterative solution module, used for iteratively solving the preset wall function based on the Newton tangent method, the dimensionless velocity initial value and the dimensionless wall distance initial value, until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met;

[0038] A numerical determination module is used to determine the target friction value and the target heat flux value corresponding to the object surface unit based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, so as to use the target friction value and the target heat flux value to complete the corresponding water-gas two-phase flow numerical simulation operation.

[0039] In a third aspect, the present application provides an electronic device, including:

[0040] Memory, used to store computer programs;

[0041] The processor is used to execute the computer program to implement the steps of the aforementioned coarse grid friction and heat flow calculation method for water-gas two-phase flow.

[0042] In a fourth aspect, the present application provides a computer-readable storage medium for storing a computer program, which, when executed by a processor, implements the steps of the aforementioned coarse-grid friction and heat flow calculation method for water-gas two-phase flow.

[0043] It can be seen that in the present application, the flow field parameters of the object surface unit are obtained, and the corresponding water transport parameters and gas transport parameters are determined based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition; the grid Reynolds number corresponding to the object surface unit is determined based on the water transport parameter and the gas transport parameter, and the dimensionless velocity initial value and the dimensionless wall distance initial value of the corresponding boundary layer are determined using the grid Reynolds number and the preset wall function; the preset wall function is iteratively solved based on the Newton tangent method, the dimensionless velocity initial value and the dimensionless wall distance initial value until the target dimensionless velocity value and the target dimensionless wall distance value are determined when the preset conditions are met; the target friction value and the target heat flow value corresponding to the object surface unit are determined based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, so as to complete the corresponding water-gas two-phase flow numerical simulation operation using the target friction value and the target heat flow value. That is, in this application, the water and gas transport parameters are first determined based on the flow field parameters of the surface unit, and then the dimensionless velocity initial value and dimensionless wall distance initial value of the boundary layer are determined using the transport parameters and the preset wall function, and then the preset wall function is iteratively solved using the Newton tangent method and the dimensionless velocity initial value and the dimensionless wall distance initial value until the preset conditions are met, and the target friction and heat flow values ​​are obtained based on the determined target dimensionless velocity value and the target dimensionless wall distance value and the wall function. In this way, the wall rigidity problem of the turbulence model can be effectively solved, and the accuracy, efficiency and stability of the friction and heat flow calculation under the coarse grid are improved, thereby greatly saving the invested computing resources and human resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0045] Figure 1 A flow chart of a method for calculating coarse grid friction and heat flow of water-gas two-phase flow provided in this application;

[0046] Figure 2 A schematic diagram of a supersonic isothermal flat plate calculation grid provided in this application;

[0047] Figure 3 A schematic diagram of the surface friction coefficient in the calculation results of a supersonic isothermal flat plate without using a wall function provided in this application;

[0048] Figure 4 A schematic diagram of heat transfer in a supersonic isothermal flat plate calculation result without using a wall function provided in this application;

[0049] Figure 5 A schematic diagram of dimensionless velocity in a supersonic isothermal plate calculation result without using a wall function provided in this application;

[0050] Figure 6 A schematic diagram of the ratio of the boundary layer temperature to the incoming flow temperature in a supersonic isothermal flat plate calculation result without using a wall function provided in the present application;

[0051] Figure 7 A schematic diagram of the surface friction coefficient in the calculation results of a supersonic isothermal flat plate using a wall function provided in this application;

[0052] Figure 8 A schematic diagram of heat transfer in a supersonic isothermal flat plate calculation result using a wall function provided in this application;

[0053] Fig. 9 A schematic diagram of dimensionless velocity in a supersonic isothermal flat plate calculation result using a wall function provided in this application;

[0054] Fig.10 A schematic diagram of the ratio of the boundary layer temperature to the incoming flow temperature in a supersonic isothermal flat plate calculation result using a wall function provided in the present application;

[0055] Fig.11 A schematic diagram of the structure of a coarse grid friction and heat flow calculation device for water-gas two-phase flow provided in this application;

[0056] Fig.12 A structural diagram of an electronic device provided for this application. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Taking the configuration of Dayun and Dake as an example, the amount of grids is basically more than 20 million. This brings a series of problems to the calculation: the aspect ratio of the normal near-wall grid is too large, which may be greater than 1000, seriously affecting the calculation accuracy and stability of the physical properties such as friction and heat flow of the grid; the grid volume is too small, limited by stability, and the local time step is very small, which seriously affects the calculation convergence speed and reduces the calculation benefit; and in optimization design, aeroelastic coupling calculation and other applications involving grid deformation reconstruction, the wall grid is too dense, which often leads to increased difficulty in grid reconstruction, reduced grid generation quality, and manual intervention is required, which reduces work efficiency.

[0059] To this end, the present application provides a coarse-grid friction and heat flow calculation solution for water-gas two-phase flow, which can effectively solve the wall rigidity problem of turbulence model, and improve the accuracy, efficiency and stability of friction and heat flow calculation under coarse grid, thereby greatly saving the invested computing resources and human resources.

[0060] See also Figure 1 As shown, the embodiment of the present invention discloses a coarse grid friction and heat flow calculation method for water-gas two-phase flow, comprising:

[0061] Step S11, obtaining flow field parameters of the object surface unit, and determining corresponding water transport parameters and gas transport parameters based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition.

[0062] In this embodiment, the flow field parameters of the object surface unit are obtained, and the corresponding water transport parameters and gas transport parameters are determined based on the flow field parameters, including: obtaining the flow field parameters of the object surface unit; the flow field parameters include corresponding density parameters, velocity parameters, pressure parameters, temperature parameters, gas mass fraction, gas volume fraction and laminar viscosity coefficient; determining the corresponding gas molecular viscosity coefficient based on the laminar viscosity coefficient, the temperature parameter and the Sutherland formula; determining the corresponding gas thermal conductivity coefficient, gas laminar Prandtl number and gas constant pressure specific heat based on the gas molecular viscosity coefficient and the flow field parameters; determining the corresponding liquid molecular viscosity coefficient, liquid thermal conductivity coefficient, liquid laminar Prandtl number and liquid constant pressure specific heat based on the flow field parameters and preset indicators. That is, in this embodiment, the relevant parameters of the object surface unit are first obtained, mainly including density, velocity, pressure, temperature, gas mass fraction, gas volume fraction, laminar viscosity coefficient, etc. And the water and gas transport parameters are calculated respectively according to the transport formula shown below:

[0063] The molecular viscosity of a gas is determined by the Sutherland formula:

[0064] ;

[0065] In the formula, for water vapor, is the viscosity coefficient of the gas under standard conditions (1 atmosphere, 0°C); T is the absolute temperature of the gas; T0 is the standard temperature; is the molecular viscosity coefficient of the gas at temperature T (subscript g means gas); S is the Sutherland constant. And there exists:

[0066] ;

[0067] ;

[0068] .

[0069] For the gas thermal conductivity , determined by the following formula:

[0070] ;

[0071] Where Pr is the laminar Prandtl number, which is generally 0.72 for gases; is the specific heat of gas at constant pressure; is the viscosity coefficient of the gas molecules.

[0072] Regarding water, the viscosity coefficient of the liquid phase (The subscript l indicates liquid) and the thermal conductivity The calculation is as follows:

[0073] ;

[0074] ;

[0075] Wherein, e is the base of natural logarithm; c1, c2, c3 are the fitting coefficients of liquid viscosity coefficient; d1, d2, d3 are the fitting coefficients of liquid thermal conductivity coefficient, which have no specific physical meaning. The preset indicators are c1, c2, c3, d1, d2, d3. The specific values ​​are shown in Table 1.

[0076] Table 1

[0077]

[0078] Furthermore, after determining the water transport parameters and the gas transport parameters, the mixture transport parameters can also be obtained according to the phase mixing law. Specifically, the corresponding mixed molecular viscosity coefficient can be determined based on the gas molecular viscosity coefficient, the first preset gas coefficient, the liquid molecular viscosity coefficient and the first preset liquid coefficient, and then the corresponding mixed thermal conductivity coefficient can be determined based on the gas thermal conductivity coefficient, the first preset gas coefficient, the liquid thermal conductivity coefficient and the first preset liquid coefficient, and then the corresponding mixed laminar Prandtl number can be determined based on the gas laminar Prandtl number, the first preset gas coefficient, the liquid laminar Prandtl number and the first preset liquid coefficient, and then the corresponding mixed constant pressure specific heat can be determined based on the gas constant pressure specific heat, the second preset gas coefficient, the liquid constant pressure specific heat and the second preset liquid coefficient, and then the mixed molecular viscosity coefficient, the mixed thermal conductivity coefficient, the mixed laminar Prandtl number and the mixed constant pressure specific heat can be used as the water-gas two-phase mixture transport parameters. The calculation formula is as follows:

[0079] ;

[0080] ;

[0081] ;

[0082] ;

[0083] In the formula, is the viscosity coefficient of the mixed molecule, and the subscript m represents mix; is the mixed heat conductivity coefficient; is the mixed laminar flow Prandtl number; is the mixed specific heat at constant pressure; is the first preset gas coefficient; is the first preset liquid coefficient; is the thermal conductivity of the gas; is the heat transfer coefficient of the liquid phase; is the second preset gas coefficient; The second preset liquid coefficient; is the liquid laminar flow Prandtl number; is the specific heat of the liquid at constant pressure. In order to improve the accuracy, the wall unit often needs to calculate the real boundary value and the numerical boundary value.

[0084] Step S12: determining a grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter, and determining a dimensionless velocity initial value and a dimensionless wall distance initial value of a corresponding boundary layer using the grid Reynolds number and a preset wall function.

[0085] Furthermore, in this embodiment, the determination of the grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter includes: determining the unit Reynolds number based on the sound velocity using the incoming flow density, the incoming flow sound velocity and the incoming flow laminar viscosity coefficient; determining the grid Reynolds number corresponding to the object surface unit using the unit Reynolds number and the mixture transport parameter. Since the Newton tangent method is very efficient and accurate in solving nonlinear equations, but it only converges within the neighborhood of the solution, the initial value and the degree of myopia of the solution directly affect the computational solution. Note that:

[0086] ;

[0087] Wherein, Rec represents the grid Reynolds number; u + represents the dimensionless velocity of the boundary layer, which is obtained by non-dimensionalizing the velocity by the parameters in the boundary layer; y + The dimensionless wall distance of the boundary layer is obtained by non-dimensionalizing the distance by the parameters in the boundary layer; represents the incoming flow density; represents the incoming flow sound velocity; Re represents the laminar viscosity coefficient of the incoming flow; a represents the unit Reynolds number based on the speed of sound, there is ; ρ is the wall unit fluid density; u is the wall unit fluid velocity; y is the distance between the center point of the wall unit and the wall; μ is the wall unit fluid viscosity coefficient. From the above formula, it can be seen that Rec is a constant when the wall parameters are constant, so u + and + The product is a constant, and u can be given by the Spalding velocity distribution approximation + Initial value:

[0088] .

[0089] At the same time, about y + After determining the initial value of the dimensionless velocity of the current boundary layer based on the Spalding velocity distribution formula and the grid Reynolds number, the Clausius-Clapeyron equation, the initial value of the dimensionless velocity, and the preset intermediate variable formula corresponding to the preset wall function can be used to determine the current preset intermediate variable value, and then the dimensionless wall distance initial value of the current boundary layer is determined based on the preset intermediate variable value, the initial value of the dimensionless velocity, and the preset wall function. That is, firstly, the Crocc-Busemann relationship based on the inner layer variable (i.e., the Clausius-Clapeyron equation) is applied inside the boundary layer to calculate the intermediate variable β (simulating the heat transfer effect) corresponding to the preset wall function, (dimensionless parameter, simulating compression effect), (temporary variable, composed of β, Determined), Q (temporary variable, determined by β, The value of the preset intermediate variable is:

[0090] ;

[0091] ;

[0092] In the formula, is the wall shear stress; is the wall temperature; is the wall heat conductivity coefficient; is the wall heat flux; r is the recovery factor, , where Pr is the laminar Prandtl number; is the wall friction velocity, ; is the wall density; is the wall laminar viscosity coefficient; is the constant pressure specific heat; B is the wall function parameter, which is 5.0. Combined with the mixture transport parameters, the value of β and other intermediate variables can be obtained, and then y can be obtained by substituting into the preset wall function. + The preset wall function is a wall function constructed by applying the White-Christoph outer layer velocity distribution (obtained from White, FM and Christoph, GH "Simple Analysis of Compressibility" Turbulent Two-Dimensional Surface Friction under Arbitrary Conditions AFFDL-TR-70-133), as shown below:

[0093] ;

[0094] In the formula, is the dimensionless wall distance in the white-Christoph outer velocity distribution; The Karman constant is 0.41.

[0095] ;

[0096] .

[0097] Step S13, iteratively solving the preset wall function based on the Newton tangent method, the dimensionless initial velocity value and the dimensionless initial wall distance value, until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met.

[0098] In this embodiment, after obtaining u + With y +After the initial value is obtained, the Newton tangent method is used for iterative solution. That is, the dimensionless initial value of the velocity is updated by the preset increment, and the preset wall function is iteratively solved based on the updated dimensionless initial value of the velocity, the Newton tangent method and the dimensionless initial value of the wall distance, until the dimensionless velocity value determined by the current iteration round meets the preset conditions; the dimensionless velocity value determined by the current iteration round is used as the target dimensionless velocity value, and the corresponding target dimensionless wall distance value is determined based on the grid Reynolds number and the target dimensionless velocity value. In other words, by + Add a small amount and apply Newton tangent method to iterate the preset wall function to get the final u + Value, that is, the target dimensionless velocity value. Since the initial value is good, generally 3 iterations are required to obtain a satisfactory result.

[0099] It is important to understand that the solution to obtain the final u + After the value, the final y + The value is obtained based on the ratio of the grid Reynolds number to the target dimensionless velocity value.

[0100] Step S14, determining a target friction value and a target heat flux value corresponding to the object surface unit based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, so as to complete the corresponding water-gas two-phase flow numerical simulation operation using the target friction value and the target heat flux value.

[0101] In this embodiment, the target friction value and target heat flux value corresponding to the object surface unit are determined based on the target dimensionless velocity value, the target dimensionless wall distance value, and the preset wall function, including: determining the corresponding wall shear stress value and wall heat flux value based on the target dimensionless velocity value, the target dimensionless wall distance value, the recovery factor, the wall temperature, and the preset intermediate variable formula corresponding to the preset wall function, so as to solve the Navier-Stokes equations of the flow field using the wall shear stress value and the wall heat flux value, and completing the corresponding water-gas two-phase flow numerical simulation operation according to the obtained solution results. That is, the object surface friction (i.e., the wall shear stress ) and heat flow (i.e., the wall heat flow ) is obtained by the relevant formula of the intermediate variable corresponding to the aforementioned preset wall function.

[0102] In addition, considering that the actual solution domain of the turbulent transport equation shrinks by one layer after the application of the wall function, it is necessary to redefine the boundary value of the turbulent variable at the first layer point away from the object surface. The SST model variable values ​​are given here:

[0103] ;

[0104] ;

[0105] ;

[0106] Where ω represents the k-ω SST turbulence model variable; ω log represents the expression of ω variable in the logarithmic rate layer; ω vis represents the expression of the ω variable in the viscous sublayer; represents the kinematic viscosity coefficient; Indicates the wall distance.

[0107] When converting to the flow field Navier-Stokes equations (NS equations, also known as Navier-Stokes equations) for solution, in order to ensure the consistency of differential discretization in the program, a proportional factor is selected to convert the heat flux and friction obtained by the preset wall function, so as to ensure that the flow field solution is completely consistent with the inapplicable wall function. For the turbulent field, due to the boundary quantity specification, the surface unit flux needs to be limited to 0.

[0108] In addition, it should be pointed out that the present application proposes an adaptive wall function that takes into account compressibility and heat conduction effects and is suitable for water-gas mixed flows. The wall function has a wide range of applications, not only for the SA model (Spalart-Allmaras single equation model, used to solve the transport equation of turbulent viscosity) and the SST model (Shear Stress Transport two-equation model, a mathematical model for turbulent simulation), but also for most other transport equation models; it is suitable for single-phase and mixed-phase flows such as water, air, and water / gas; the grid has a wide range of applicability, y + As a grid feature scale, it can range from 1 to 500, with little effect on the calculation results. By applying this wall function, the calculation accuracy of lift, drag, and heat flow under coarse grids is greatly improved. Under the condition of ensuring the same accuracy, the normal grid for water-gas two-phase flow calculation can be greatly relaxed, which improves the convergence speed and greatly saves computing resources.

[0109] It can be seen that in the present application, the flow field parameters of the object surface unit are obtained, and the corresponding water transport parameters and gas transport parameters are determined based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition; the grid Reynolds number corresponding to the object surface unit is determined based on the water transport parameter and the gas transport parameter, and the dimensionless velocity initial value and the dimensionless wall distance initial value of the corresponding boundary layer are determined using the grid Reynolds number and the preset wall function; the preset wall function is iteratively solved based on the Newton tangent method, the dimensionless velocity initial value and the dimensionless wall distance initial value until the target dimensionless velocity value and the target dimensionless wall distance value are determined when the preset conditions are met; the target friction value and the target heat flow value corresponding to the object surface unit are determined based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, so as to complete the corresponding water-gas two-phase flow numerical simulation operation using the target friction value and the target heat flow value. That is, in this application, the water and gas transport parameters are first determined based on the flow field parameters of the surface unit, and then the dimensionless velocity initial value and dimensionless wall distance initial value of the boundary layer are determined using the transport parameters and the preset wall function, and then the preset wall function is iteratively solved using the Newton tangent method and the dimensionless velocity initial value and the dimensionless wall distance initial value until the preset conditions are met, and the target friction and heat flow values ​​are obtained based on the determined target dimensionless velocity value and the target dimensionless wall distance value and the wall function. In this way, the wall rigidity problem of the turbulence model can be effectively solved, and the accuracy, efficiency and stability of the friction and heat flow calculation under the coarse grid are improved, thereby greatly saving the invested computing resources and human resources.

[0110] Combine the following Figure 2-10 The schematic diagram disclosed in the figure specifically illustrates the technical solution of the embodiment of the present application.

[0111] Taking the calculation of supersonic isothermal wall as an example, in a specific implementation method, let the incoming flow Mach number M = 2, and the Reynolds number Re with the length of the flat plate as the characteristic scale = 1×10 7 , wall temperature T w =1.5Tinf, where Tinf is the incoming flow temperature. The supersonic condition is quite different from the subsonic condition. Due to the high Mach number, even when the incoming flow temperature is much lower than the wall, the wall is still a cold wall, that is, the wall temperature is lower than the recovery temperature, and the heat flow should be directed from the flow field to the object surface. By two-dimensionalization, we can get Figure 2 The calculation grid of the plate shown in the figure is encrypted in the normal direction. It should be pointed out that dimensionless is generally performed in numerical calculations. In essence, a bunch of characteristic quantities are taken, such as the characteristic length of the plate, the flow density, the speed of sound, etc., and the actual physical quantity is divided by these quantities, which are called dimensionless quantities for easy analysis and calculation. Figure 2The grid in is dimensionless with a characteristic length of 1 meter, that is, Figure 2 The units of the horizontal and vertical coordinates are both meters.

[0112] When performing calculations, 1) obtain all flow field parameters of the surface unit and calculate the transport coefficient; 2) calculate the grid Reynolds number of the surface unit, and calculate u based on the grid Reynolds number + Initial value; 3) Solve the formula to obtain heat flow, friction resistance and other quantities, and calculate the relevant parameters according to the formula. 4) After calculating the β parameter, obtain other parameters according to the relevant formula of the intermediate variable corresponding to the preset wall function, and calculate y from the preset wall function + Initial value; 5) Apply Newton tangent method to solve the preset wall function to obtain the final u + value, iterate 5 times; 6) solve u + After that, + The grid Reynolds number is used to obtain the object surface friction and heat flux, and the object surface friction and heat flux are obtained from the relevant formulas of the intermediate variables corresponding to the preset wall function.

[0113] In this embodiment, the calculation is very stable under different sequence grids. The preset wall function has basically no destructive effect on the flow field solution. On the contrary, due to the thinning of the grid, the flow field converges faster, and the calculation efficiency is taken into consideration while ensuring the calculation accuracy.

[0114] Combination Figure 3-6 As shown, when the preset wall function in this application is not used, the calculation results show a large dispersion as the grid is thinned. + When it reaches 20, the heat flux error is very large. The White & Christoph in the figure is the outer velocity distribution of White-Christoph. Figure 7-10 As shown, after using the preset wall function in the present application, the calculation results are almost the same under different grid sequences, which reflects the effectiveness of the preset wall function.

[0115] See also Fig.11 As shown, the embodiment of the present application also discloses a coarse grid friction and heat flow calculation device for water-gas two-phase flow, including:

[0116] The transport parameter determination module 11 is used to obtain the flow field parameters of the object surface unit, and determine the corresponding water transport parameters and gas transport parameters based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition;

[0117] An initial value determination module 12 is used to determine the grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter, and determine the dimensionless velocity initial value and the dimensionless wall distance initial value of the corresponding boundary layer by using the grid Reynolds number and a preset wall function;

[0118] An iterative solution module 13 is used to iteratively solve the preset wall function based on the Newton tangent method, the dimensionless velocity initial value and the dimensionless wall distance initial value, until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met;

[0119] The numerical determination module 14 is used to determine the target friction value and the target heat flux value corresponding to the object surface unit based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, so as to use the target friction value and the target heat flux value to complete the corresponding water-gas two-phase flow numerical simulation operation.

[0120] Among them, for more specific working processes of the above-mentioned modules, please refer to the corresponding contents disclosed in the aforementioned embodiments, which will not be repeated here.

[0121] It can be seen that in this application, the water and gas transport parameters are first determined based on the flow field parameters of the surface unit, and then the dimensionless velocity initial value and dimensionless wall distance initial value of the boundary layer are determined using the transport parameters and the preset wall function. Then, the preset wall function is iteratively solved using the Newton tangent method and the dimensionless velocity initial value and the dimensionless wall distance initial value until the preset conditions are met. The target friction value and target heat flow value are obtained based on the determined target dimensionless velocity value, target dimensionless wall distance value and wall function. In this way, the wall rigidity problem of the turbulence model can be effectively solved, and the accuracy, efficiency and stability of the friction and heat flow calculation under the coarse grid are improved, thereby greatly saving the invested computing resources and human resources.

[0122] In some specific embodiments, the transport parameter determination module 11 may specifically include:

[0123] A flow field parameter acquisition unit, used to acquire the flow field parameters of the object surface unit; the flow field parameters include corresponding density parameters, velocity parameters, pressure parameters, temperature parameters, gas mass fraction, gas volume fraction and laminar viscosity coefficient;

[0124] A first gas transport parameter determination unit, configured to determine a corresponding gas molecule viscosity coefficient based on the laminar viscosity coefficient, the temperature parameter and the Sutherland formula;

[0125] A second gas transport parameter determination unit, configured to determine a corresponding gas thermal conductivity coefficient, a gas laminar flow Prandtl number, and a gas constant-pressure specific heat based on the gas molecular viscosity coefficient and the flow field parameter;

[0126] The water transport parameter determination unit is used to determine the corresponding liquid molecular viscosity coefficient, liquid thermal conductivity coefficient, liquid laminar flow Prandtl number, and liquid constant pressure specific heat based on the flow field parameters and preset indicators.

[0127] In some specific embodiments, the coarse grid friction and heat flow calculation device for water-gas two-phase flow may further include:

[0128] A mixed molecular viscosity coefficient determining unit, configured to determine a corresponding mixed molecular viscosity coefficient based on the gas molecular viscosity coefficient, the first preset gas coefficient, the liquid molecular viscosity coefficient and the first preset liquid coefficient;

[0129] a mixed heat transfer coefficient determination unit, configured to determine a corresponding mixed heat transfer coefficient based on the gas heat transfer coefficient, the first preset gas coefficient, the liquid heat transfer coefficient, and the first preset liquid coefficient;

[0130] a mixed laminar flow Prandtl number determining unit, configured to determine a corresponding mixed laminar flow Prandtl number based on the gas laminar flow Prandtl number, the first preset gas coefficient, the liquid laminar flow Prandtl number, and the first preset liquid coefficient;

[0131] a mixed constant-pressure specific heat determination unit, configured to determine a corresponding mixed constant-pressure specific heat based on the gas constant-pressure specific heat, a second preset gas coefficient, the liquid constant-pressure specific heat, and a second preset liquid coefficient;

[0132] The mixture transport parameter determination unit is used to use the mixture molecular viscosity coefficient, the mixture heat conductivity coefficient, the mixture laminar flow Prandtl number and the mixture constant pressure specific heat as the mixture transport parameters of the water-gas two-phase mixture.

[0133] In some specific embodiments, the initial value determination module 12 may specifically include:

[0134] A unit Reynolds number determination unit, used for determining a unit Reynolds number based on the sound velocity by using the incoming flow density, the incoming flow sound velocity and the incoming flow laminar viscosity coefficient;

[0135] A grid Reynolds number determination unit is used to determine the grid Reynolds number corresponding to the object surface unit by using the unit Reynolds number and the mixture transport parameter.

[0136] In some specific embodiments, the iterative solution module 13 may specifically include:

[0137] An iterative solution unit, used to update the dimensionless initial velocity value using a preset increment, and iteratively solve the preset wall function based on the updated dimensionless initial velocity value, Newton's tangent method and the dimensionless initial wall distance value until the dimensionless velocity value determined in the current iteration round meets the preset condition;

[0138] The target value determination unit is used to use the dimensionless velocity value determined in the current iteration round as a target dimensionless velocity value, and determine a corresponding target dimensionless wall distance value based on the grid Reynolds number and the target dimensionless velocity value.

[0139] In some specific embodiments, the initial value determination module 12 may specifically include:

[0140] A velocity initial value determination unit, used for determining the dimensionless velocity initial value of the current boundary layer based on the Spalding velocity distribution formula and the grid Reynolds number;

[0141] A variable value determination unit, used to determine a current preset intermediate variable value by using the Clausius-Clapeyron equation, the dimensionless velocity initial value, and a preset intermediate variable formula corresponding to a preset wall function;

[0142] The distance initial value determining unit is used to determine the dimensionless wall distance initial value of the current boundary layer based on the preset intermediate variable value, the dimensionless velocity initial value and the preset wall function.

[0143] In some specific embodiments, the value determination module 14 may specifically include:

[0144] A numerical determination unit is used to determine the corresponding wall shear stress value and the wall heat flux value based on the target dimensionless velocity value, the target dimensionless wall distance value, the recovery factor, the wall temperature and the preset intermediate variable formula corresponding to the preset wall function, so as to use the wall shear stress value and the wall heat flux value to solve the Navier-Stokes equations of the flow field, and complete the corresponding water-gas two-phase flow numerical simulation operation according to the obtained solution results.

[0145] Furthermore, the present application also discloses an electronic device. Fig.12 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content in the diagram cannot be considered as any limitation on the scope of use of the present application.

[0146] Fig.12A schematic diagram of the structure of an electronic device 20 provided in an embodiment of the present application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the coarse grid friction and heat flow calculation method for water-gas two-phase flow disclosed in any of the aforementioned embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0147] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0148] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon can include an operating system 221, a computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0149] The operating system 221 is used to manage and control the hardware devices and computer program 222 on the electronic device 20, and can be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program that can be used to complete the coarse grid friction and heat flow calculation method of the water-gas two-phase flow performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include computer programs that can be used to complete other specific tasks.

[0150] Furthermore, the present application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned coarse grid friction and heat flow calculation method for water-gas two-phase flow is implemented. The specific steps of the method can be referred to the corresponding contents disclosed in the aforementioned embodiments, and will not be repeated here.

[0151] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0152] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0153] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0154] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0155] The technical solution provided by the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technicians in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A coarse grid friction and heat flow calculation method for water-gas two-phase flow, characterized in that: include: Acquire flow field parameters of the object surface unit, and determine corresponding water transport parameters and gas transport parameters based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition; Determine a grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter, and determine a dimensionless velocity initial value and a dimensionless wall distance initial value of a corresponding boundary layer using the grid Reynolds number and a preset wall function; Iteratively solving the preset wall function based on the Newton tangent method, the dimensionless initial velocity value and the dimensionless initial wall distance value, until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met; Determine a target friction value and a target heat flux value corresponding to the object surface unit based on the target dimensionless velocity value, the target dimensionless wall distance value, and the preset wall function, so as to complete a corresponding water-gas two-phase flow numerical simulation operation using the target friction value and the target heat flux value; Wherein, the method of determining the dimensionless velocity initial value and the dimensionless wall distance initial value of the corresponding boundary layer by using the grid Reynolds number and the preset wall function includes: Determine the dimensionless initial velocity value of the current boundary layer based on the Spalding velocity distribution formula and the grid Reynolds number; Determine the current preset intermediate variable value by using the Clausius-Clapeyron equation, the dimensionless velocity initial value, and a preset intermediate variable formula corresponding to the preset wall function; The dimensionless wall distance initial value of the current boundary layer is determined based on the preset intermediate variable value, the dimensionless velocity initial value and the preset wall function.

2. The method for calculating coarse grid friction and heat flow of water-gas two-phase flow according to claim 1, characterized in that: The acquiring flow field parameters of the object surface unit and determining corresponding water transport parameters and gas transport parameters based on the flow field parameters include: Obtaining flow field parameters of the object surface unit; the flow field parameters include corresponding density parameters, velocity parameters, pressure parameters, temperature parameters, gas mass fraction, gas volume fraction and laminar viscosity coefficient; Determining a corresponding gas molecule viscosity coefficient based on the laminar viscosity coefficient, the temperature parameter and the Sutherland formula; Determining the corresponding gas thermal conductivity coefficient, gas laminar flow Prandtl number, and gas constant-pressure specific heat based on the gas molecular viscosity coefficient and the flow field parameters; Based on the flow field parameters and preset indicators, the corresponding liquid molecular viscosity coefficient, liquid thermal conductivity coefficient, liquid laminar flow Prandtl number, and liquid constant-pressure specific heat are determined.

3. The method for calculating coarse grid friction and heat flow of water-gas two-phase flow according to claim 2, characterized in that: After determining the corresponding water transport parameters and gas transport parameters based on the flow field parameters, the method further includes: Determining a corresponding mixed molecular viscosity coefficient based on the gas molecular viscosity coefficient, the first preset gas coefficient, the liquid molecular viscosity coefficient, and the first preset liquid coefficient; determining a corresponding mixed heat transfer coefficient based on the gas heat transfer coefficient, the first preset gas coefficient, the liquid heat transfer coefficient, and the first preset liquid coefficient; Determining a corresponding mixed laminar Prandtl number based on the gas laminar Prandtl number, the first preset gas coefficient, the liquid laminar Prandtl number, and the first preset liquid coefficient; Determine a corresponding mixed constant-pressure specific heat based on the gas constant-pressure specific heat, the second preset gas coefficient, the liquid constant-pressure specific heat, and the second preset liquid coefficient; The mixed molecular viscosity coefficient, the mixed heat conductivity coefficient, the mixed laminar flow Prandtl number and the mixed constant-pressure specific heat are used as transport parameters of the water-gas two-phase mixture.

4. The method for calculating coarse grid friction and heat flow of water-gas two-phase flow according to claim 3, characterized in that: The determining of the grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter comprises: Determine the unit Reynolds number based on the sound velocity using the incoming flow density, incoming flow sound velocity and incoming flow laminar viscosity coefficient; The grid Reynolds number corresponding to the object surface unit is determined by using the unit Reynolds number and the mixture transport parameter.

5. The method for calculating coarse grid friction and heat flow of water-gas two-phase flow according to claim 1, characterized in that: The iterative solution of the preset wall function based on the Newton tangent method, the dimensionless initial velocity value and the dimensionless initial wall distance value until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met includes: The dimensionless initial velocity value is updated by using a preset increment, and the preset wall function is iteratively solved based on the updated dimensionless initial velocity value, the Newton tangent method, and the dimensionless initial wall distance value until the dimensionless velocity value determined in the current iteration round meets the preset condition; The dimensionless velocity value determined in the current iteration round is used as a target dimensionless velocity value, and a corresponding target dimensionless wall distance value is determined based on the grid Reynolds number and the target dimensionless velocity value.

6. The method for calculating coarse grid friction and heat flow of water-gas two-phase flow according to claim 1, characterized in that: The determining of a target friction value and a target heat flux value corresponding to the object surface unit based on the target dimensionless velocity value, the target dimensionless wall distance value, and the preset wall function includes: Based on the target dimensionless velocity value, the target dimensionless wall distance value, the recovery factor, the wall temperature and the preset intermediate variable formula corresponding to the preset wall function, the corresponding wall shear stress value and the wall heat flux value are determined, so as to use the wall shear stress value and the wall heat flux value to solve the Navier-Stokes equations of the flow field, and complete the corresponding water-gas two-phase flow numerical simulation operation according to the obtained solution results.

7. A coarse grid friction and heat flow calculation device for water-gas two-phase flow, characterized in that: include: A transport parameter determination module, used to obtain the flow field parameters of the object surface unit, and determine the corresponding water transport parameters and gas transport parameters based on the flow field parameters; wherein the object surface unit refers to the first layer of coarse grid on the surface of the object, and the coarse grid is a grid whose grid size meets the preset coarse size condition; An initial value determination module, used to determine the grid Reynolds number corresponding to the object surface unit based on the water transport parameter and the gas transport parameter, and determine the dimensionless velocity initial value and the dimensionless wall distance initial value of the corresponding boundary layer by using the grid Reynolds number and a preset wall function; An iterative solution module, used for iteratively solving the preset wall function based on the Newton tangent method, the dimensionless velocity initial value and the dimensionless wall distance initial value, until a target dimensionless velocity value and a target dimensionless wall distance value are determined when preset conditions are met; a numerical determination module, for determining a target friction value and a target heat flux value corresponding to the object surface unit based on the target dimensionless velocity value, the target dimensionless wall distance value and the preset wall function, so as to complete a corresponding water-gas two-phase flow numerical simulation operation using the target friction value and the target heat flux value; Wherein, the initial value determination module includes: A velocity initial value determination unit, used for determining the dimensionless velocity initial value of the current boundary layer based on the Spalding velocity distribution formula and the grid Reynolds number; A variable value determination unit, used to determine a current preset intermediate variable value by using the Clausius-Clapeyron equation, the dimensionless velocity initial value, and a preset intermediate variable formula corresponding to a preset wall function; The distance initial value determining unit is used to determine the dimensionless wall distance initial value of the current boundary layer based on the preset intermediate variable value, the dimensionless velocity initial value and the preset wall function.

8. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the coarse grid friction and heat flow calculation method for water-gas two-phase flow according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: Used to store a computer program, which, when executed by a processor, implements the coarse grid friction and heat flow calculation method for water-gas two-phase flow as described in any one of claims 1 to 6.

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