基于多孔介质理论的粮层阻力数值模拟.pdf

摘要粮食安全是影响国民经济和社会发展的重大战略问题,粮食供给和价格问题影响着CPI和城乡社会和谐发展。由于缺少通风出现粮食损耗的现象,所以研究粮层通风特性具有十分重要的意义。粮食颗粒群具有多孔介质特性,基于多孔介质理论研究粮食通风成为一项重要的内容。本文基于多孔介质理论,利用计算流体力学方法对粮层阻力模拟并与试验测试的粮层压降数据进行对比,证明模拟方法可行的能较准确的反应压降规律,估算出压降数值,模拟与实测的吻合度较好。利用数值模拟的办法可以估算出最经济的风速和风压,为选择合适的风机容量提供参考。利用计算流体力学方法做微观多孔介质的内部流场分析,计算不同多孔介质骨架中的颗粒形状和颗粒大小对内部的影响和分布,对比分析了随着入口速度增大后的最大速度、最大压强、最大强湍动能和耗散率等参数的变化趋势。计算分析了随着速度增大三种压力梯度关系,从微观上解释粮食层压降变化的原因。关键词:多孔介质;粮食通风;湍流;计算流体力学Simulation of Grain Layer Resistance Based on the Theory of Porous MediaAbstractFood safet y affects the nat ional economic and social food supply and price influence the CPI and urban and rural harmonious development of societ of the lack of vent ilat ion result ed in the grain loss. So we are especially meaningful to study the grain layer vent ilat ion properties. Food particles group has porous medium characterist on the theory of porous media to study the grain vent ilat ion and e an important on porous medium theory,this paper using the computat ional fluid dynamics method simulatesthe grain layer same t ime teststhe grain layer pressure drop data. Comparing simulat ion data and test data proves that the simulat ionmethod is feasible, simulat ion method can accurately response law of the pressure simulat ion method can be used to estimate the optimal wind speed and wind pressure. Can be used to guide choosing appropriate fan capacit the computational fluid dynamics method to study the int ernal flow field in the micro porous particle shape and particle size of different skeleton of porous media's influence on the int ernal and distribut the different inlet velocit y, maximum speed, maximum pressure and maximum turbulent ic energy and dissipat ion rate of ion and analysis th