摘要
水平环中的自然对流在工程中有着广泛的应用.本文使用光滑粒子法(SPH)对水平环中的自然对流进行数值研究.用文献中同心和偏心水平环的实验和数值结果来验证SPH方法.通过改变两个无量纲参数,即半径比和瑞利数来研究不同的情况.根据不同的半径比和瑞利数,确定了三种对流状态,即无羽流、单羽流和双羽流.数值结果表明,当瑞利数在10^(4)或更大的数量级时产生羽流.高半径比限制了羽流的发展,导致自然对流强度降低.羽流的方向和数量随着内圆环在不同方向偏移和偏心率的变化而改变.
Natural convection in horizontal annuli is widely used in engineering applications.This paper numerically investigates natural convection in horizontal annuli using smoothed particle hydrodynamics(SPH).Experimental and numerical findings of concentric and eccentric horizontal annuli from the literature were used to validate the SPH method.Different cases were studied by changing two dimensionless parameters,namely,the radius ratio and Rayleigh number.Three convection states were identified from numerical simulations with different radius ratios and Rayleigh numbers,namely,no plume,one plume and two plumes.The numerical results indicated that the plume is generated when the Rayleigh number is in the order of 10^(4) or larger and that a high radius ratio limits the development of the plume and the strength of natural convection was reduced.The direction and number of the plumes fluctuated as the inner cylinder travels in different directions and the eccentricity changes.
作者
张为
杨秀峰
Wei Zhang;Xiufeng Yang(Beijing Institute of Technology,School of Aerospace Engineering,Beijing,100081,China)
基金
supported by the National Natural Science Foundation of China(Grant Nos.12172049 and 12032005)
The authors would like to thank the reviewers for their helpful comments.
