模拟界面换热系数和密度对热溶质对流影响

Numerical simulation of the influence of heat extract boundary conditions and desities on the thermo-solutal convection

为了能够更好地控制凝固过程热和溶质的传输,以二元合金为例,研究了在单边散热条件下,不同界面换热系数和密度对热溶质对流的影响.研究表明:当材料密度一定时,随着界面换热系数的提高,沿散热方向上的温度梯度增大,热溶质对流的效果增强;当界面换热系数为1000W/(m2·K)时,在凝固初期铸件底部出现涡流现象;在界面换热系数不变的情况下,随着材料密度的增加,铸件内液体金属的热溶质对流效应减弱.

Influences of different heat extracted boundary conditions and densities on thermo-solutal convection are investigated during solidification process of single heat extracted boundary. Results show that the temperature gradient along with the heat-extracted direction enlarges and the convection is strengthened. When the interface heat transfer coefficient is 1 000 W/(m2·K) , there is a vortex in the bottom side of ingot in the early solidification. The convection decreases with the increasing of the desity.