具有质热源的方腔内对流传热传质及其非线性特性

Study on heat and mass transfer and nonlinear characteristics with heat and mass source in cavity

以火灾为背景,对一个带有质热源的方腔进行了研究.针对不同Ra,浮升力比Nc,Sr和Df,探讨了腔内流体的传热传质规律及其非线性特性.结果表明,存在临界Rac使流体流动由导热驱动流动转变为对流驱动流动,随着Ra增大质热源表面传热传质强度增加,流体由稳态流动转为振荡流动.当Nc>?1时,对流传热系数和对流传质系数增大,流体由稳态转化为倍周期振荡,最后转化为混沌.增大Sr和Df可增强传热传质能力.

In this paper, a square cavity with mass and heat source was studied with the background of fire. According to the different Rayleigh number(Ra) and buoyance ratio Nc, Sr and Df, the heat and mass transfer law and nonlinear characteristics of the fluid in the cavity are discussed. The results show that the critical Rac causes the fluid flow to change from the heat-induced driving flow to the convection-driven flow. As Ra increases the heat and mass transfer of the surface of the heat and mass source, the fluid changes from steady-state flow to oscillating state. When Nc>-1, the convective heat transfer coefficient and the convective mass transfer coefficient increase, and the fluid transforms from steady state to double-period oscillation, and finally to chaos. Increasing Sr and Df can increase flow and heat and mass transfer.