平行风风速对腔体复合热损失特性影响的数值模拟

Numerical Simulation on Effect of Side-on Wind Speed on Combined Heat Loss Characteristics of a Cavity

在恒热流边界条件和不同平行风风速下,考虑通过保温层和腔体壁面的导热热损失,采用三维数值模拟方法对一侧全开的圆柱形腔体复合对流和辐射热损失特性进行研究。结果表明:平行风下,腔体内的温度分布和开口面速度分布都与无风时存在很大差异;随着风速的增大,对流热损失平均努塞尔数Nu_c单调递增,而辐射热损失平均努塞尔数Nu_r并不单调递减,且风速越大,变化越不明显;随着腔体倾角的增大,同一风速下Nu_c和Nu_r并不像无风时那样单调变化。

Considering conduction heat loss through the insulation and cavity wall,3D numerical simulation has been carried out to investigate the impact of the side-on wind speed on combined convection and surface radiation heat losses characteristics of a fully open cylindrical cavity with all surfaces heated by constant heat flux.Results reveal that the temperature contours inside the cavity and the velocity contours on the aperture plane under side-on wind environment are quite different from that of no wind case.With the increasing of side-on wind speed,average convection heat loss Nusselt number Nu_c goes up gradually with wind speed.However,as wind speed increases,average radiation heat loss Nusselt number Nu_r decreases monotonously,and then increases slightly.With the increasing of wind speed,the variation of Nu_r becomes more and more insensitive.With the increasing of inclined angle,Nu_c and Nu_r under certain wind speed do not always vary monotonically as that of no-wind cases.