Euler-Lagrange iterative solid-liquid phase transition prediction method and device

Abstract

The present invention discloses an Euler-Lagrangian iterative solid-liquid phase change prediction method and device. The method externally couples the Lagrangian iteration for calculating the relative motion of solid phase change materials to the Euler iteration for calculating phase change flow and heat transfer. The method comprises the following steps: determining the computational domain, boundaries, and initial conditions; solving the force balance equation for the solid phase change material to obtain the resultant force; explicitly calculating the initial relative motion velocity of the solid phase change material; substituting the relative motion velocity into the phase change flow and heat transfer governing equation within the Lagrangian iteration; solving the flow and heat transfer governing equation within the Euler iteration; updating the flow and heat transfer physical field and terminating the Euler iteration if the Euler iteration converges; implicitly calculating the relative motion velocity of the solid phase change material; and updating the relative motion velocity and terminating the Lagrangian iteration if the Lagrangian iteration converges. The method achieves strongly coupled prediction of solid-liquid phase change flow and heat transfer and the relative motion of solid phase change materials, with an average error of only 4.93% and a reduction of 51% in numerical oscillation, thus having engineering application value.

Description

Technical Field

[0001] The present invention relates to the field of phase change heat transfer prediction, and in particular to a method and device for predicting the solid-liquid phase change flow heat transfer process and the relative motion state of a solid phase change material by using Euler-Lagrangian internal and external iterative coupling. Technical Background

[0002] In distributed energy and thermal control systems, solid-liquid phase transitions are widely used in energy storage devices due to their advantages, including high latent heat of phase change, strong temperature control capabilities, and excellent thermal stability. During solid-liquid phase transitions, external forces can cause relative motion of the solid phase change material within the molten liquid phase change material, thereby affecting the flow and heat transfer process of the solid-liquid phase transition. Simultaneously, this flow and heat transfer process further influences the solid-liquid phase transition and alters the relative motion of the solid phase change material. Therefore, the flow and heat transfer process of the solid-liquid phase transition and the relative motion of the solid phase change material are strongly coupled. For example, when the phase change material melts from all sides under the influence of gravity, the solid phase change material undergoes a downward motion and undergoes contact melting. Compared to non-contact melting, the phase transition rate of contact melting can be increased by 1-5 times. Therefore, the stable and accurate coupled prediction of the flow and heat transfer process of the solid-liquid phase transition and the relative motion of the solid phase change material is of great significance for the design and optimization of energy storage devices.

[0003] Due to the large number of design parameters of solid-liquid phase change devices, it is costly and difficult to conduct research entirely using experimental methods. Numerical prediction methods have the advantages of low cost and large data volume, and have become an important method for studying solid-liquid phase change flow and heat transfer. Journal article 1 (Voller VR, Prakash CA fixed grid numerical modeling methodology for convection-diffusion mushy region phase-change problems [J]. International Journal of Heat and Mass Transfer, 1987, 30 (8): 1709-1719) proposed an enthalpy-porous solid-liquid phase change prediction method. This method uses the enthalpy value of the material to introduce the latent heat of solid-liquid phase change into the energy conservation equation, assumes the solid-liquid phase change region to be a porous medium region, and suppresses the flow in this region by reducing the porosity of the solid phase change material region, thereby achieving the tracking of the solid-liquid phase change interface on a fixed grid. In recent years, this method has been widely used in the prediction of solid-liquid phase change flow and heat transfer processes, and can accurately predict non-contact solid-liquid phase change processes. However, the enthalpy-porous solid-liquid phase change prediction method does not consider the relative motion of solid phase change materials during the modeling process and cannot accurately predict the relative motion state of solid phase change materials.

[0004] Journal article 2 (Daniel Hummel, Stefan Beer, Andreas Hornung. A conjugate heat transfer model for unconstrained melting of macro-encapsulated phase change materials subjected to external convection [J]. International Journal of Heat and Mass Transfer, 2020, 149: 119-205) proposed a solid-liquid phase change prediction method. This method takes into account the stress state of the solid phase change material during the melting process and uses the Newmark integral method to calculate the relative motion velocity of the solid phase change material. This method can predict the flow heat transfer process of the solid-liquid phase change and the relative motion of the solid phase change material. However, in the inner loop of this method, the pressure and velocity fields used to calculate the relative motion of the solid phase change material do not necessarily strictly satisfy the momentum conservation equation, resulting in severe numerical oscillations in the relative motion velocity of the solid phase change material.

[0005] As can be seen from this, existing prediction methods for solid-liquid phase change simulations can accurately calculate the non-contact solid-liquid phase change process. However, it is still difficult to stably and accurately couple the prediction of the flow and heat transfer process of the solid-liquid phase change with the relative motion of the solid phase change material. This makes it impossible to adapt to the design and optimization requirements of existing solid-liquid phase change energy storage devices. Therefore, there is an urgent need for a prediction method and device to solve these problems and promote the development of optimized energy storage device design. Summary of the Invention

[0006] In response to the problems existing in existing methods, the present invention proposes a solid-liquid phase change prediction method and device based on Euler-Lagrangian iteration. The present invention innovatively nests the Lagrangian iteration for solving the force balance equation of solid phase change materials and the Euler iteration for calculating the solid-liquid phase change flow heat transfer control equation. Through the inner Euler iteration and the outer Lagrangian iteration, the present invention can stably and accurately strongly couple the calculation of the flow heat transfer process of the solid-liquid phase change and the relative motion state of the solid phase change material, thereby solving the problem that existing methods are difficult to couple the prediction of the solid-liquid phase change flow heat transfer process and the relative motion of the solid phase change material.

[0007] The present invention implements the proposed Euler-Lagrangian iterative solid-liquid phase transition prediction method through the following technical solution, which includes the following steps:

[0008] Step 1: Determine the calculation area and boundary conditions, and determine the physical field of the solid-liquid phase change flow and heat transfer process and the relative motion speed of the solid phase change material at the initial time step iteration;

[0009] Step 2: Based on the flow and heat transfer physical field in step 1, solve the force balance equations of the solid phase change material and calculate the resultant force on the solid phase change material at the beginning of the current time step iteration;

[0010] Step 3: Based on the relative motion velocity in step 1 and the resultant force in step 2, the explicit advance method is used to calculate the relative motion velocity of the solid phase change material in the initial Lagrangian iteration in the current time step;

[0011] Step 4: Based on the relative motion velocity of the solid phase change material and the resultant force, the additional source term method is used in the Lagrangian iteration to introduce the relative motion velocity of the solid phase change material into the governing equations of the solid-liquid phase change flow heat transfer process;

[0012] Step 5: Based on the control equations in step 4, the pressure-velocity coupling algorithm is used in the Euler iteration within the Lagrangian iteration to iteratively solve the control equations of the solid-liquid phase change flow heat transfer process;

[0013] Step 6: Determine whether the solid-liquid phase change flow heat transfer process in the current Euler iteration has converged; if not, continue the Euler iteration solution; if converged, update the physical field of the flow heat transfer process and stop the Euler iteration;

[0014] Step 7: Based on the updated physical field in step 6, solve the force balance equations of the solid phase change material in the Lagrangian iteration to calculate the updated resultant force on the solid phase change material;

[0015] Step 8: Based on the updated resultant force in step 7, the implicit iteration method is used in the Lagrangian iteration to calculate the updated relative motion velocity of the solid phase change material;

[0016] Step 9: Determine whether the relative motion state of the solid phase change material in the current Lagrangian iteration has converged; if not, substitute the current relative motion velocity of the solid phase change material into step 4 and continue the Lagrangian iteration; if converged, update the relative motion velocity of the solid phase change material and stop the Lagrangian iteration;

[0017] Step 10: Output the physical field of the solid-liquid phase change flow and heat transfer process and the relative motion velocity of the solid phase change material calculated in the current time step, and complete the calculation of the solid-liquid phase change process of the Euler-Lagrangian iteration in the current time step.

[0018] The preferred solution further includes any of the following technical features:

[0019] The physical fields in step one include physical fields such as pressure, velocity and temperature in the solid-liquid phase change flow heat transfer process; the physical fields and relative motion velocity at the initial moment or the previous time step can be used as the iterative initial conditions of the current time step.

[0020] The equilibrium equations in step 2 may be force equilibrium equations among pressure, viscous force, gravity, inertial force and other forces acting on the solid phase change material.

[0021] In step three, an explicit advancement method of differential equations, such as the forward Euler method and the prediction-correction method, can be used to calculate the relative motion speed of the solid phase change material at the initial iteration of the current time step.

[0022] In the step 4, an additional source term method such as an extended Darcy source term can be used to introduce the relative motion velocity of the solid phase change material into the control equations of the solid-liquid phase change flow heat transfer process.

[0023] In step five, a pressure-velocity coupling algorithm such as SIMPLE, PISO, or COUPLED may be used to iteratively solve the control equations of the solid-liquid phase change flow heat transfer process.

[0024] The convergence criterion of the Euler iteration in step six is ​​that the residuals of the control equations such as mass, momentum and energy conservation of the solid-liquid phase change flow heat transfer process are all less than the set convergence residual criterion.

[0025] In step eight, a nonlinear equation implicit iteration method such as the secant method, the improved secant method, or a differential equation implicit iteration method such as the backward Euler method and the Simpson method can be used to calculate the relative motion velocity of the updated solid phase change material.

[0026] The convergence criterion of the Lagrangian iteration in step nine is that the residuals of the relative motion velocity of the solid phase change material and the resultant force are both less than the set convergence residual criterion.

[0027] An Euler-Lagrange iterative solid-liquid phase change prediction device includes a processor, a memory, and a computer program stored in the memory and capable of running on the processor. The processor can execute the computer program and implement the steps of any method described in the above technical solutions.

[0028] A computer-readable storage medium can store a computer program, wherein the program, when executed by a processor, implements the steps of the method described in any one of the above technical solutions.

[0029] Compared with the prior art, the present invention has the following beneficial technical effects:

[0030] The present invention innovatively couples the Lagrangian iteration for calculating the relative motion of solid phase-change materials externally to the Euler iteration for calculating solid-liquid phase-change flow and heat transfer. The internal Euler iteration is used to update the physical field of the solid-liquid phase-change flow and heat transfer process based on the relative motion state of the solid phase-change material. The external Lagrangian iteration is used to update the relative motion state of the solid phase-change material based on the physical field of the solid-liquid phase-change flow and heat transfer process. Compared to the prediction method proposed in Journal Paper 1, which lacks modeling of the relative motion of solid phase-change materials, the present invention can couple the solution of the solid-liquid phase-change flow and heat transfer process with the relative motion state of the solid phase-change material. This reflects the advanced nature of the present invention in the physical modeling process.

[0031] In the present invention, the flow heat transfer physical field that has been calculated to converge within the Euler iteration is used to update the relative motion state of the solid phase change material within the Lagrangian iteration. Therefore, the pressure, velocity, and temperature fields used to update the relative motion state of the solid phase change material in the present invention all satisfy the mass, momentum, and energy conservation equations. However, in the prediction method proposed in Journal Paper 2, the physical field obtained after solving the pressure correction equation is used to update the relative motion state of the solid phase change material. Although this physical field satisfies the mass conservation equation, it does not necessarily strictly satisfy the momentum conservation equation, resulting in serious numerical oscillations in the relative motion velocity of the solid phase change material obtained by solution. The total variation in the relative motion velocity of the solid phase change material during the solid-liquid phase transition process is used as the standard for evaluating numerical oscillations. Compared with Journal Paper 2, the numerical oscillation of the calculation results of the present invention has decreased by 51%. This reflects the accuracy and stability of the present invention in phase change prediction.

[0032] The present invention can solve the flow heat transfer process of solid-liquid phase change and the relative motion state of solid phase change material by nesting the Euler-Lagrangian inner and outer double-layer iteration. -Haagen, Stephan Dieter Brüggemann (2018, 117:757-767) proposed an implicit solid-liquid phase change prediction method that can weakly couple the flow heat transfer of solid-liquid phase change and the relative motion of solid phase change materials. Compared with the weak-coupling solution format in journal article 3, the strong-coupling prediction method proposed in this paper can enhance the robustness of phase change prediction. This further reflects the stability of the present invention in the prediction process.

[0033] In this invention, the Lagrangian iteration is coupled externally to the overall Euler iteration. This allows the prediction method to use existing computational fluid dynamics programs, such as Fluent or OpenFoam, as an implementation tool for the Euler iteration, thereby externalizing the Lagrangian iteration to the existing computational fluid dynamics program. This demonstrates the excellent feasibility and portability of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a flow chart of the Euler-Lagrangian iterative solid-liquid phase transition prediction method of the present invention;

[0035] Figure 2 A schematic diagram of the geometric model and boundary conditions of the calculation area according to an embodiment of the present invention;

[0036] Figure 3 A phase distribution comparison diagram of the experimental results of Journal Article 3, the calculation results of the enthalpy-porous solid-liquid phase transition prediction method, and the Euler-Lagrange iterative solid-liquid phase transition prediction method in an embodiment of the present invention;

[0037] Figure 4 Comparison curve of liquid volume fraction calculated by the numerical results of Journal Article 2, experimental results of Journal Article 3, enthalpy-porous solid-liquid phase transition prediction method and Euler-Lagrange iterative solid-liquid phase transition prediction method in the embodiment of the present invention;

[0038] Figure 5 This is a comparison curve of the relative motion speed of solid phase change materials in the embodiment of the present invention, including the numerical results of journal article 2, the experimental results of journal article 3, and the calculation results of the Euler-Lagrange iterative solid-liquid phase change prediction method. DETAILED DESCRIPTION

[0039] Provide specific implementation cases of the present invention below:

[0040] like Figure 2As shown, the geometric model of the calculation area of ​​the solid-liquid phase change energy storage device in this embodiment is a rectangular square cavity with a side length of 40 mm. The solid-liquid phase change material used in this embodiment is RT35 paraffin, and its phase change temperature range is 307.65K to 309.15K. The four walls of the square cavity are isothermal and have no-slip boundary conditions, and their wall temperature is 313.15K. The influence of gravity is taken into account in this embodiment, and the direction of gravity is always along the negative direction of the Y axis. The initial pressure field of the solid-liquid phase change flow heat transfer process is 0 Pa, the initial velocity field is 0 m / s, and the initial temperature field is 303.15K. The melting of RT35 paraffin can cause a thermal volume expansion of approximately 7%. Therefore, the solid phase change material will melt and produce a sinking movement relative to the liquid phase change material under the action of gravity. The initial relative motion velocity of the solid phase change material is 0 m / s, and the initial net force is 0 N. Since the problem to be solved is symmetric about the Y axis, this embodiment assumes that the relative motion and the resultant force of the solid phase change material in the X axis direction are both 0, and only considers the relative motion and the resultant force in the Y axis direction.

[0041] Step 1: Based on the above working condition description, determine the calculation area and boundary conditions of this embodiment, and convert the pressure, velocity, and temperature fields (p t ,u t , T t ) and the relative motion speed of the solid phase change material (V t ) as the iterative initial condition for the current time step The subscript t+1 represents the current time step t+1, and the superscript 0 represents the 0th Lagrangian iteration at the beginning of the iteration.

[0042] Step 2: Based on the solid-liquid phase change flow heat transfer physics field at the initial iteration in step 1 According to the D'Alembert principle, solve the force balance equations of solid phase change materials

[0043]

[0044]

[0045] G y =e y ·∫ m g·e y dm;

[0046] I y =-∫ m dV / dt dm;

[0047] F=P y +D y +G y +I y ;

[0048] Where P is pressure, p is pressure, n is the unit vector in the normal direction of the solid phase change material interface, e is the unit vector of the Cartesian coordinate system, D is the viscous force, τ is the shear stress tensor, s is the area of ​​the solid phase change material interface, G is gravity, g is the acceleration of gravity, I is the inertial force, V is the relative motion speed of the solid phase change material, t is the solution time, m is the mass of the solid phase change material, and the subscripts x and y represent the components of the variables along the X-axis and Y-axis respectively; the resultant force on the solid phase change material at the beginning of the current time step iteration is then calculated.

[0049] Step 3: Based on the relative movement speed of the solid phase change material in step 1 The resultant force in step 2 Explicit Euler method

[0050]

[0051] Where ω is the sub-relaxation factor and Δt is the time step of the numerical calculation; thus the relative motion velocity of the solid phase change material in the initial Lagrangian iteration in the current time step is calculated:

[0052] Step 4: Relative motion speed based on solid phase change materials In the Lagrangian iteration, the extended Darcy source term is used

[0053]

[0054]

[0055] Where S is the extended Darcy source term, A m is the mushy zone coefficient, α is the liquid phase volume fraction, ε is a decimal to avoid the denominator being zero, u is the speed of the liquid phase change material, and V is the relative motion speed of the solid phase change material; thus, the relative motion speed of the solid phase change material is Introducing the governing equations of solid-liquid phase change flow heat transfer process

[0056]

[0057]

[0058]

[0059] Where x is the Cartesian coordinate, t is the solution time, ρ is the density, μ is the dynamic viscosity, λ is the thermal conductivity, u is the velocity, p is the pressure, H is the total enthalpy, which includes the sensible heat and latent heat of the solid-liquid phase change process, T is the temperature, γ is the thermal volume expansion coefficient, δ is the Kronecker function, S is the extended Darcy source term, the subscript r is the reference value of the variable, and the subscripts i and j are the free and dummy scales of the tensor, respectively, which can be x and y, representing the components of the variable along the x-axis and y-axis.

[0060] Step 5: Based on the control equations in step 4, in the Euler iteration within the Lagrangian iteration, the transient terms, convection terms, and diffusion terms of the control equations are numerically discretized using the first-order implicit, second-order upwind, and central difference schemes, respectively. The interpolation of the pressure field and the reconstruction of the gradient field are calculated using the body force weighted scheme and the least squares method, respectively. The SIMPLE algorithm is then used to iteratively solve the control equations of the solid-liquid phase change flow heat transfer process.

[0061] Step 6: Determine whether the residuals of the mass conservation equation, momentum conservation equation, and energy conservation equation in the current Euler iteration are less than 10 -5 , 10 -8 with 10 -10 , to determine whether the flow heat transfer process of solid-liquid phase change has converged; if the residual of the control equation group is greater than the set convergence standard, the Euler iteration has not converged, and the Euler iteration is continued; if the residual of the control equation group is less than the set convergence standard, the Euler iteration has converged, and the physical field of the solid-liquid phase change flow heat transfer process is updated. And stop the Euler iteration.

[0062] Step 7: Based on the updated physics in step 6 In the Lagrangian iteration, solve the force balance equations of the solid phase change material in step 2 and calculate the updated resultant force on the solid phase change material.

[0063] Step 8: Based on the updated resultant force in step 7 In the Lagrange iteration, the secant root method of the nonlinear equation is used

[0064]

[0065] In the formula, the superscripts k-1, k and k+1 represent the k-1th, kth and k+1th Lagrangian iterations respectively, where k is a natural number greater than zero; thus, the relative motion speed of the solid phase change material after the update is calculated as

[0066] Step 9: Determine whether the residuals of the relative motion velocity of the solid phase change material and the resultant force in the current Lagrangian iteration are less than 10 -6with 10 -12 , to determine whether the relative motion state of the solid phase change material has reached convergence; if the residual of the relative motion speed or the resultant force is greater than the set convergence standard, the Lagrangian iteration has not converged, and the current relative motion speed of the solid phase change material is Substitute into step 4 and continue the Lagrangian iteration; if the residuals of the relative motion velocity and the resultant force are less than the set convergence standard, the Lagrangian iteration has converged, and the relative motion velocity of the solid phase change material is updated. and stops the Lagrangian iteration.

[0067] Step 10: Output the physical field of the solid-liquid phase change flow heat transfer process in the current time step (p t+1 ,u t+1 , T t+1 ) and the relative motion speed of the solid phase change material (V t+1 ) to complete the Euler-Lagrangian iterative solid-liquid phase change calculation for the current time step.

[0068] Based on the above working conditions and methods, Figure 3 The experimental results of Journal Article 3 in this embodiment, the phase distribution comparison diagram of the calculation results of the enthalpy-porous solid-liquid phase change prediction method and the Euler-Lagrange iterative solid-liquid phase change prediction method are shown. Figure 3 The black part is solid phase change material, while the white part is liquid phase change material. Figure 3 As shown in the experimental results of the journal article 3 in (ac), solid phase change materials will sink relative to liquid phase change materials under the action of gravity during the melting process. Figure 3 As shown in (df), the enthalpy-porous solid-liquid phase transition prediction method does not correctly predict the sinking motion of the solid phase change material, and the solid is non-physical suspended in the liquid. Figure 3 (gi) As can be seen, this prediction method accurately predicts the melting process and sinking motion of solid phase change materials. Because the enthalpy-porous solid-liquid phase transition prediction method uses a Darcy source term to constrain the fluid velocity within the solid phase change material grid in the momentum conservation equation, it does not consider the modeling of the relative motion of the solid phase change material. This reflects the advanced nature of this invention in the physical modeling process.

[0069] Figure 4The numerical results of Journal Paper 2, the experimental results of Journal Paper 3, and the liquid phase volume fraction comparison curves calculated by the enthalpy-porous solid-liquid phase change prediction method and the Euler-Lagrange iterative solid-liquid phase change prediction method in the embodiment of the present invention are shown. It can be seen that the change trend of the liquid phase volume fraction calculated by this prediction method is similar to the experimental results of Journal Paper 3, with an average relative error of 4.93% and a maximum relative error of 7.84%. At the same time, the liquid phase volume fraction curve calculated by this prediction method basically coincides with the results of Journal Paper 2, reflecting the consistency of the two methods in calculating the phase change flow heat transfer process. However, the enthalpy-porous solid-liquid phase change prediction method has a huge error in the calculation of the working conditions of this embodiment. Under actual working conditions, the complete melting time of the solid phase change material is about 1500s, while the complete melting time calculated by the enthalpy-porous solid-liquid phase change prediction method is about 6400s, which seriously underestimates the melting rate of the solid phase change material. Because the solid is non-physically suspended in the liquid during the simulation of the enthalpy-porous solid-liquid phase transition prediction method, its heat transfer distance is large and the melting rate is low, which reflects the accuracy of the present invention in phase change flow heat transfer prediction.

[0070] Figure 5 The comparative curve of the relative motion velocity of solid phase change materials of the numerical results of Journal Paper 2, the experimental results of Journal Paper 3 and the calculation results of the Euler-Lagrange iterative solid-liquid phase change prediction method in the embodiment of the present invention is shown. It can be seen that the trend of the relative motion velocity of the solid phase change material calculated by this prediction method is similar to the numerical results of Journal Paper 2, and the relative motion velocity of this prediction method is included in the experimental results of Journal Paper 3. This reflects the accuracy of the solid-liquid phase change prediction method proposed in the patent of this invention for calculating the relative motion velocity of solid phase change materials. Comparing the calculation results of this prediction method with the numerical results of Journal Paper 2, it can be found that the numerical oscillation of the relative motion velocity in the calculation results of this prediction method is smaller than that of Journal Paper 2. If the total variation of the relative motion velocity of the solid phase change material during the solid-liquid phase change process is used as the standard for evaluating the numerical oscillation, the larger the total variation, the more serious the numerical oscillation. The total variation of Journal Paper 2 is 1.27×10 -4 The total variation of this prediction method is 6.17×10 -5 , which is a 51% decrease compared to the result of Journal Paper 2. This reflects the stability of the solid-liquid phase change prediction method proposed in this patent for calculating the relative motion velocity of solid phase change materials.

Claims

1. An Euler-Lagrangian iterative solid-liquid phase transition prediction method, characterized in that: The Lagrangian iteration used to calculate the relative motion state of the solid phase change material is externally coupled to the Euler iteration used to calculate the solid-liquid phase change flow and heat transfer process. Through the double-layer nesting of the inner Euler iteration and the outer Lagrangian iteration, a strong coupling prediction of the solid-liquid phase change flow and heat transfer process and the relative motion state of the solid phase change material is achieved. The specific steps include: Step 1: Determine the calculation area and boundary conditions, and determine the physical field of the solid-liquid phase change flow and heat transfer process and the relative motion speed of the solid phase change material at the initial time step iteration; Step 2: Solve the force balance equations of the solid phase change material and calculate the resultant force on the solid phase change material at the beginning of the current time step iteration; Step 3: Use the explicit advancement method to calculate the relative motion velocity of the solid phase change material in the initial Lagrangian iteration in the current time step; Step 4: In the Lagrangian iteration, the additional source term method is used to introduce the relative motion velocity of the solid phase change material into the governing equations of the solid-liquid phase change flow and heat transfer process; Step 5: In the Euler iteration within the Lagrangian iteration, the pressure-velocity coupling algorithm is used to iteratively solve the governing equations of the solid-liquid phase change flow heat transfer process; Step 6: Determine whether the flow and heat transfer process of the solid-liquid phase change in the current Euler iteration has converged; if not, continue the Euler iteration solution; if converged, update the physical field of the solid-liquid phase change flow and heat transfer process and stop the Euler iteration; Step 7: In the Lagrangian iteration, solve the force balance equations of the updated solid phase change material and calculate the resultant force acting on the updated solid phase change material; Step 8: In the Lagrangian iteration, the implicit iteration method is used to calculate the relative motion velocity of the updated solid phase change material; Step 9: Determine whether the relative motion state of the solid phase change material in the current Lagrangian iteration has converged; if not, substitute the current relative motion velocity of the solid phase change material into step 4 and continue the Lagrangian iteration; if converged, update the relative motion velocity of the solid phase change material and stop the Lagrangian iteration; Step 10: Output the physical field of the solid-liquid phase change flow and heat transfer process and the relative motion velocity of the solid phase change material calculated in the current time step, and complete the calculation of the solid-liquid phase change process of the Euler-Lagrangian iteration in the current time step.

2. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The physical fields of the solid-liquid phase change flow heat transfer process in step 1 include pressure field, velocity field and temperature field.

3. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The equilibrium equations in step 2 are equilibrium equations for the pressure, viscous force, gravity and inertial force acting on the solid phase change material.

4. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The explicit propulsion method in step three includes the forward Euler method and the prediction-correction method.

5. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The additional source term method in step 4 includes an extended Darcy source term.

6. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The pressure-velocity coupling algorithm in step five includes SIMPLE, PISO, and COUPLED algorithms.

7. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The convergence criterion of the Euler iteration in step six is ​​that the residuals of the mass, momentum and energy conservation control equations of the solid-liquid phase change flow heat transfer process are all less than the set convergence residual criterion.

8. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The implicit iterative method in step eight includes the secant method, the improved secant method, the backward Euler method, and the Simpson integral method.

9. The Euler-Lagrange iterative solid-liquid phase transition prediction method according to claim 1, characterized in that: The convergence criterion of the Lagrangian iteration in step nine is that the residuals of the relative motion velocity of the solid phase change material and the resultant force are both less than the set convergence residual criterion.

10. An Euler-Lagrange iterative solid-liquid phase transition prediction device, characterized by: The method comprises a processor, a memory, and a computer program stored in the memory and capable of running on the processor. The processor can execute the computer program and implement the steps of the method according to any one of claims 1 to 9.

11. A computer-readable storage medium capable of storing a computer program, wherein: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

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