多孔介质中盐指现象的数值模拟

Numerical simulation of salt finger convection in porous media

运用基于杂交网格的高精度数值方法研究了多孔介质中的盐指现象.该算法将基于边界拟合坐标下的高精度有限差分法和高精度的泊松方程快速求解器有效地结合在一起,从而达到提高整体的计算精度、计算效率和稳定性的目的.通过比较不同孔隙率的多孔介质对盐指对流的传热传质效应的影响,发现在标准孔隙率较低的多孔介质中,盐度扩散的速度明显比热扩散的速度快,盐指很快触及上下壁面,使得上下层的盐度梯度迅速减小,这是与非多孔介质具有明显差异之处.

The dual-mesh hybrid numerical method is used to investigate the salt finger convection, as well as the heat and mass transfer, in saturated porous media. It is found that at low normalized porosity of porous media, saline diffusion is much faster than thermal diffusion. The fingers grow straightly to the top and bottom walls, which would lessen the saline gradient of stratified system. Also, it is indicated that the hybrid method is perfect for dealing with small scale convection in porous media because of its great veracity, efficiency and stability.