猪活动区域多孔介质模型及其阻力系数的CFD模拟

旨在尝试将躺卧姿势下的猪体简化成不同几何形状以求取其阻力系数,并分析它们的差异性。本研究采用校核过的CFD模型,模拟探究了简化猪模型、半椭球模型、椭球模型和半圆柱模型4种不同躺卧猪模型对猪群区域在X、Y和Z3个垂直方向上阻力系数的影响,分析了4种模型对猪栏内气流以及压力分布的影响。结果表明,椭球模型的惯性阻力系数相比半椭球模型与半圆柱模型更加接近简化猪模型,其在X、Z和Y方向上的惯性阻力系数与简化猪模型之间的相对误差分别为-4.0%、-12.2%和14.7%,并且气流与压力分布基本一致。因此,采用椭球模型代替简化猪模型进行建模计算不仅能保证准确度还能有效提高计算效率。

CFD simulation on porous media model and resistant coefficients of pig occupied zone

The objective of this study was to calculate the resistant coefficients of different simplified lying pig geometric models and analyze the differences. In this study, the validated CFD model was applied to investigate the effect of four different simplified geometric models of lying pigs on the resistant coefficients in X, Y and Z directions in pig occupied zone for porous media modeling. The four geometric models were simplified pig model, ellipsoid model, half ellipsoid model, and half cylinder model. The influence of the four geometric models on the relationship between wind speed and pressure distribution in the pig occupied zone was also analyzed. The results showed that the inertial resistant coefficients of ellipsoid model were closer to the simplified pig model than the half ellipsoid model and the half cylinder model. The relative errors of inertial resistant coefficients between ellipsoid model and simplified pig model in X, Z, and Y directions were -4. 0%, -12. 2% and 14. 7%, respectively. In addition, the wind speed and pressure distribution of ellipsoid model and simplified pig model were basically consistent. Therefore, the ellipsoid model instead of the simplified pig model can not only ensure the accuracy, but also effectively improve the calculation efficiency.