谷物层内部非稳态温度场的有限元解

利用求解微分方程的边值问题和泛函求极值问题的等价性,进行了谷物干燥过程中谷物层内部非稳态温度场的有限元解尝试。对热传导偏微分方程的泛函形式进行有限元离散、求极值、形成有限元方程的过程。为预测谷物干燥过程中谷层内部温度场随时间的变化情况提供了有效途径。同时进行了实验验证,结果基本吻合。在无人工送风的情况下,流入表层热量的测定和谷物导热系数的选择是影响预测精度的主要因素。该项研究为更复杂情况的模拟打下了基础。

Finite Element Methods Solution of Unstable Temperature-Field Inside Grain-Layer

By using the equivalence between the solution of boundary problem for differential equation and functional extreme value, cut-and-try methods are used for the finite element methods (FEM) , solution of unstable temperature-field inside grain-layer in the process of grain drying. A process is introduced to transform functional heat transfer partial differential equation into FEM discreteness, solution of extreme value and forming FEM equation . It provides an effective channel for predicting variation of temperature-field inside grain-layer in the process of grain drying with time. Meanwhile, it is experimentally verified with the satisfactory results. Without man-made airflow, the major factors affecting prediction accuracy are the measurement of flow-in surface heat and the selection of heat conductivity value of grain. This study lays down the foundation for simulation of more complex cases.