传热薄壁物体存在条件探讨

本文详细分析了处于对流换热环境下实际物体(厚壁物体,物体内温度是时间、空间的函数)转化为薄壁物体(温度只是时间的函数)的条件。分析了目前各种作为薄壁物体判据的合理性与局限性,在此基础上,提出了以物体内最大的无量纲温度梯度小于某一常数作为薄壁物体的判据,并分析了Fo数与Bi数对这一判据的影响。

Discussion of the Existent Condition for Thermally Thin Wall Body

This paper discusses the conditions of translation from a thermally wall body into a thermally thin body, the former the temperature is both functions of time and space, the later the temperature is single function of time under connective heat tranfer circumstance. On the bases of analysing the reasonableness and limitation of all criteria of thin wall body at present, a new criterion of thin wall body has been developted, in which the largest dimensionless temperature gradient is considered less than a certain constant, and the effect of Fo and Bi numbers on the new criterion has also been demonstrated.