二维倾斜方腔水自然对流分离过程模拟分析  

Numerical Analysis of Separation Process of Water Natural Convection in Slant Two-dimensional Rectangular Cavity

作　　者：孟凡康[1] 

机构地区：[1]辽宁工程技术大学,辽宁阜新123000

出　　处：《流体机械》2013年第1期30-34,共5页Fluid Machinery

摘　　要：以水为传热介质,对温差驱动的二维方腔内自然对流换热过程进行了模拟分析。利用流体流动与热量传递的无因次控制方程,采用热线及流线可视化方法,取相同Ra=5×107值,倾斜角为控制参数,讨论分析了方腔中的温度、流动及对流换热传输结构。给出了倾斜角对于流型、分离点、对流换热传输结构及高低温壁面的传热性能的影响。分析结果表明:当Ra=5×107时,随着的θ增大,双涡结构越来越明显,倾斜角度对于方腔的流动的流型,具有较大的影响;分离点从低温壁面下部开始形成,随着倾斜角的增大分离点沿着低温壁面向上流动,接着到达绝热壁面,最终到达高温壁面;温度梯度受θ变化的影响较大,不同θ时,产生温度梯度最大值的地点不同;高低温壁面的平均Nu在60°最大,180°时最小。Taking water as heat transfer medium, the numerical analysis of natural convection driven by temperature difference in two - dimensional rectangular cavity is conducted. The temperature profile, fluidal profile and convection transmission structure is analyzed. In the analysis, the dimensionless governing equations of fluid flow and heat transfer is used, the visualization meth- od of heatline and streamline is used, taking the same Ra value as Ra = 5 × 10^7 and taking the inclination as control parameter. This paper gives the influence of the inclination on flow pattern, separation point, the heat convection transmission structure and the beat transfer performance of the high and the low temperature wall. The results of analysis show the following conclusion： when Ra = 5 × 10^7, with the increase of θ, the double eddy structure is more and more obvious and the inclination has larger in- fluence on the flow pattern in cavity ; the separation point begins form in the lower part of low temperature wall and flow up along with the low temperature wall with the increase of inclination, then it reached the adiabatic wall and finally get to the high temper- ature wall;θ has larger influence on the temperature gradient and when θis different, the location where the temperature gradient is largest is different; the average Nu of high and low temperature wall is largest when the inclination is 60° and least when the in- clination is 180°.

关 键 词：二维方腔 水 自然对流 热线 倾斜角 分离点 数值模拟 

分 类 号：TH12[机械工程—机械设计及理论] TQ028[化学工程]