Abstract:

A numerical simulation of natural convection was conducted in the middle of a rectangular cavity with a heater of variable dimension.Analyses on isotherms, streamlines and average Nusselt number in the rectangular cavity were carried out by varying the values of dimensionless height b and Rayleigh number.The simulation results show that b and Ra have a great effect on the natural convection in the rectangular cavity.Nu_ave grows with the increase of b and Ra, and the growth rate is proportional to Ra and inversely proportional to b.

Key words:

自然对流, 封闭方腔, 内热源, 数值模拟

摘要：

对底部中心位置具有不同大小内热源的二维封闭方腔自然对流换热问题进行了数值模拟。通过改变内热源量纲1高度b和Rayleigh数的大小，分析了不同工况对封闭方腔内温度场、流场结构和热源表面平均Nusselt数的影响。数值模拟结果表明：b和Ra的大小对封闭方腔内空气的流动换热有着重要影响;热源表面Nu_ave是Ra和b的增函数，且其增幅随Ra的增加而增加，随b的增加而减小。

关键词:

自然对流, 封闭方腔, 内热源, 数值模拟