方腔内双扩散混合对流振荡特性研究  

The Study of Oscillating Characteristic of Double Diffusive Mixed Convection in an Enclosure

作　　者：李贝贝[1] 孙文科 吕浩[1] 肖瑞雪[1] 徐洪涛[1] 杨茉[1] 

机构地区：[1]上海理工大学能源与动力工程学院,上海200093 [2]国核工程有限公司,上海200233

出　　处：《工程热物理学报》2015年第4期874-878,共5页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.51276117)

摘　　要：本文利用计算流体力学CFD技术,对内置发热圆的方腔内双扩散混合对流的振荡特性进行了数值模拟研究。发热圆为高温高浓度且位于方腔中心,低温低浓度的流体从方腔左侧底部流进,右侧顶部流出。在不同的理查德数Ri(0.001≤Ri≤1.0)和发热圆直径和方腔边长的比值S(0.2≤S≤0.6)下,利用时间历程和相空间轨迹法来量化分析方腔内部的振荡特性。研究结果表明:当Ri=0.001时,在S=0.6的情况下,方腔内双扩散混合对流呈现出周期性振荡状态;在S=0.2和0.4的情况下,方腔内双扩散混合对流呈现出非周期性振荡状态。而当Ri≥0.005时,无论S为多大,方腔内双扩散混合对流均呈现出稳定流动状态。This article adopts CFD(Computational Fluid Dynamics)technology to numerically analyze the oscillating characteristic of double diffusive mixed convection around a heated cylinder in an enclosure.The heated cylinder is located at the center of the enclosure with high temperature and concentration.The inlet flow with low temperature and concentration is located at the lower-left wall of the enclosure while the exit is located at the upper-right wall.The combined effects of Richardson number Ri(0.001≤ Ri ≤1.0) and the ratio of diameter to enclosure length S(0.2≤ S ≤0.6) are studied to inspect the oscillatory behaviors in the enclosure.The time history analysis and phase space trajectory are adopted to quantify the oscillatory characteristics.The results show that,at Ri=0.001,the periodic oscillation occurs at S=0.6 and the non-periodic oscillation appears at S=0.2 and 0.4.At Ri ≥0.005,the flow is always constant over time and independent of S.

关 键 词：方腔 双扩散混合对流 振荡 数值模拟 

分 类 号：TK124[动力工程及工程热物理—工程热物理]