倾斜射流对移动平板表面紊动和传热特性的影响

采用雷诺应力湍流模型和Simplic算法对半封闭槽道内倾斜射流冲击移动平板的流动和传热特性进行了数值模拟,研究了不同射流角度和不同平板移动速度下平板近壁湍动能和板面努塞尔数的变化.结果表明：射流角度和平板运动速度对平板近壁湍动能和表面努塞尔数值分布影响显著;当入射角与平板运动方向相同时,板速的升高提高了近壁面的湍动能,但是降低了冲击区域的局部努塞尔数值;平板表面的平均努塞尔数值随板速的提高先降低后大幅升高,高速下角度对平板表面的平均传热效果影响较小;当入射角为80°,平板运动方向与入射方向相反且板速和射流速度相同时,在移动平板表面能够获得较佳的紊动和传热效果.

Influence of Oblique Impinging Jet on Flow and Heat Transfer Characteristics on Surface of a Moving Flat Plate

Flow and heat transfer characteristics on surface of a moving flat plate impinged by an oblique confined slot-jet were numerically studied using Reynolds stress turbulence model and SIMPLIC algo- rithm, so as to investigate how the jet angle and plate velocity influence the turbulent kinetic energy near the wall and the Nusselt number distribution on plate surface. Results show that the jet angle and plate ve- locity play an important role in influencing the turbulent kinetic energy and the Nusselt number distribu- tion. When the jetting angle is in the same direction as the moving plate, turbulent kinetic energy near the wall increases while local Nusselt number at the impinging point decreases with rising plate speed. The av- erage Nusselt number decreases initially and then increases substantially with the increase of plate velocity. At high plate velocity, jet angle affects little on average heat transfer efficiency of the plate surface. Under the condition that the jet angle is 80~, the moving direction of plate is opposite to the incidence angle of jet flow, and the jet flow rate is same as that of the moving plate, better effects of turbulence and heat trans- fer will be obtained on the wall surface.