三维半封闭空间自然对流的流动与换热研究

AN INVESTIGATION OF THREE-DIMENSIONAL NATURAL CONVECTION IN A LARGE ASPECT RATIO OPEN CAVITIES

本文用SIMPLER法,对三维半封闭空腔内的自然对流问题进行了数值求解,从而揭示了这种空腔内自然对流的流型和传热机理。在此基础上进一步给出了太阳能集热管内的换热准则关系式,计算参数范围:Gr=4.14×10~3—4.14×10~7,Pr=0.7—7.0,L/D=4—30。为验证数学模型的准确性,相应地实测了集热管内的温度分布,实测结果与数值计算结果非常吻合。

Using the SIMPLER method, a numerical study of three dimensional natural convection in a large aspect ratio open cavities has been performed. The flow patterns and heat transfer mechanism in this cavity was clearly revealed. Based on numerical results a correlation for natural convection heat transfer in solar collector tube was recommended iri the range of Gr = 4.14×103-4.14×107, Pr = 0.7-7.0 and L/D = 4-30. The temperature distribution of the fluid was measured in a test collector tube, and the results obtained by numerical method was in good agreement with those of the experimental measurements.