Coupling the force flow field with the phase field model for the isothermal growth of dendrite, Sola algorithm is used to calculate the flow speed and pressure of liquid metal, Using double grid numerical method to reduce the calculation amount of computer simulation, The space factor and time factor are introduced to improve the accuracy of double grid numerical calculation, Taking Al-2%-Cu alloy as an example, the dendrite growth process of the binary alloy under forced convection environment is simulated; The simulation results can capture the real dendrite growth and interactions of the liquid metal flow in the process of dendrite growth under forced convection environment: In the incident flow regions, the dendrite morphology is complex, the secondary dendrite is lush and the growth speed is fast due to the influence of liquid metal flow. In the back flow regions, the growth of dendrite changes the flowing pressure among the liquid metals, it causes the regional complex flow patterns and there are two opposite eddy current; the grow speed of the main branch which grows perpendicular to the initial flow direction is the fastest and presents tilt growth phenomenon. When the space coefficient value is appropriate, the dual mesh method can save calculation time effectively.

Coupling the force flow field with the phase field model for the isothermal growth of dendrite multiple grains, Sola algorithm is used to calculate the flow speed and pressure of liquid metal, double grid numerical method was used to reduce the calculation amount of computer simulation, the space factor and time factor were introduced to improve the accuracy of double grid numerical calculation, Taking Al-2%-Cu alloy for example, the dendrite growth process of the binary alloy was simulated under forced convection environment; Simulation results can capture the real dendrite growth and interactions of the liquid metal flow in the process of dendrite growth under forced convection environment: The flow of metal liquid affects the growth morphology of dendrite multi-grain. The flow of liquid metal changes the growth speed of dendrite tip in different directions for each dendrite, the greater of the liquid metal initial flow speed, the worse of dendrite morphology symmetry; different initial flow speeds result in the different distance between each dendrite. The metal liquid forced flow causes the instability of dendrite growth interface, it changes the degree of undercooling, composition, dendrite tip growth rate and the curvature radius of dendrite tip in the dendrite growth forefront interface. For the forefront dendrite growth interface free energy system, the dendrite tip growth speed and curvature radius were adjusted by the competitive growth of dendrite tips, thus reached a new stable state for the interface, which resulted in the emergence of bifurcation in dendrite tips. The liquid metal flow speed between different grains was affected by the relative position and morphology between different grains, and also affected by the initial inflow speed of the liquid metal.