The direct numerical simulation (DNS) method, in which there is not any experimental model used for the porous media, is proposed to simulate fluid flow in porous media. A two dimensional DNS mode is implemented based on a computational fluid dynamics (CFD) software Fluent to investigate the flow resistance and pressure drop in the porous media. Two geometrical configurations, I.e.,Inline and staggered geometrical configurations packed with cylindrical particles, are used in the simulations. The pressure drop for inline geometrical configurations simulated from DNS is 53. 5Pa, which approaches the valve 55. 6 Pa obtained from the Ergun equation model with the original coefficients of A = 150, B = l. 75. The pressure drop for staggered geometrical configurations simulated from DNS is 65.1 Pa, which approaches the valve 62. lPa obtained from the Ergun equation model with the modified coefficients of A=180, B = l. 80. The staggered geometrical configuration with cylindrical parti-cles is more exact than the inline configuration for modeling the real porous media materials. Therefore, the DNS results confirm that the modified coefficient pair (A=180, B=1.80) is more suitable for Ergun equation model than the original coefficient pair (A = 150, B = 1. 75). The DNS method proposed in this paper can be further applied to predicate the coefficients for Ergun equation or to develop other porous model, by using different geometrical configurations packed with different shape of particles.%基于计算流体动力学软件Fluent建立了一个二维DNS模型,研究了多孔介质中的流动阻力和压降.模拟时对填充的圆柱粒子采用了2种几何排列方式,即直排和叉排.DNS直排模型的压差为53.5 Pa,接近于采用原始系数A=150,B=1.75的尔格方程计算结果55.6 Pa.叉排模型的压差为65.1 Pa,接近于采用修正系数A=180,B=1.80的尔格方程计算结果62.1 Pa.对于真实多孔介质材料的模拟来说,圆柱形粒子叉排比直排更为准确.因此DNS结果确认了修正系数组(A=180,B=1.80)比原始系数组(A=150,B=1.75)更适合尔格方程模型.应用文中推荐的DNS方法,通过采用不同的粒子几何排列方式、填充不同形状的粒子可以进一步地预测尔格方程系数或改善其他的多孔介质模型.
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