一种考虑结构瞬态互辐射的有限元法

研究结构元件之间瞬态辐射过程及特点 ,对于元件温度未知时的瞬态辐射提出了一种有限元计算模型。通过广义边界条件简化了元件互辐射的数学描述 ,最后得到了广义互辐射元。所建模型具有简单、方便、实用和精度高等特点 ,使复杂的互辐射计算化为统一模式 ,并通过试验与实例计算证明其有效性。

NEW FINITE ELEMENT METHOD FOR TRANSIENT MUTUAL-RADIATION IN STRUCTURE

A new finite element method is proposed to simulate the transient process of mutual radiation among parts of structures. A radiation element is developed by using the general variational method. The radiation process between different parts of the structure is treated as general boundary conditions. In this way, the complicated process of mutual radiation can be greatly simplified. To validate the established method, experimental investigation is produced by use of a thin wall semi column shell made of 45# steel plate. An iodin tungsten light tube lying in the center of the column shell is used as the source of heat and the heat field is measured by distributed thermoelectric couples. Transient temperatures at different locations are recorded up to about 400℃. Numerical analyses show that the effect of mutual radiation increases as the temperature rising. Numerical results with consideration of the mutual radiation coincide very well with the test record. Therefore, the established method is not only simple but has high accuracy as well.