局部内热源和外部加热同时作用时部分开口空腔内自然对流的数值研究

NUMERICAL STUDY OF NATURAL CONVECTION IN AN EXTERNALLY HEATED PARTIAL CAVITY WITH ALOCAL SOURCE

具有内热源的空腔内的自然对流广泛地存在于核反应堆设计,建筑物火灾及电子器件冷却等领域,近年来已受到研究者的重视。文献[1,2]对均匀分布内热源和外部加热引起的封闭空腔内的自然对流进行了数值分析与试验。作者曾对局部内热源和外部加热同时作用引起的封闭空腔内的层流自然对流进行了系统的研究,并对单独由外部加热时部分开口空腔内的自然对流进行了数值计算。

Unsteady and steady, two-dimensional, laminar natural convection is numerically investigated in an externally heated partial cavity with a local source. Velocity and temperature profiles, average and local Nusselt numbers on the hot and cold surfaces, and the characteristics of the opening are given. The numerical results show that, with an increase in the Ra** or Rae, there occur five flow patterns in the partial cavity when the opening is made from the lower cold surface, and there occur two types of flow regimes, each of which includes five flow patterns, when the opening is made from the upper cold surface. The performances of flow and heat transfer in the cavity are significantly infuenced by such factors as external Rayleigh number, relative intensity of local heat source, opening size and location.