矩形管内纵向涡强化传热研究

将纵向涡强化换热技术应用于矩形管槽,研究以水为换热介质在过渡流状态下的换热效果。实验结果表明有纵向涡发生器的换热效果明显优于无纵向涡发生器的情况。利用PHEON ICS计算软件对实验进行数值模拟,模拟值与实验值符合较好。在此基础上,改变纵向涡的翼高和形状来模拟,发现两者均为换热影响的因素,相比之下,高宽比为0.4纵向涡发生器的换热效果比高宽比为0.5和0.6的要好。而采用相同高宽的矩形翼时,N u高于三角翼,但其换热性能指标却低于直角三角翼。

Heat transfer enhancement in rectangular pipe with longitudinal vortex

Heat transfer in rectangular pipe with longitudinal vortex generators were investigated under transitional flow using water as working fluid.The experimental results show that heat transfer of water is greatly enhanced in rectangular pipe with longitudinal vortex generators.Numerical simulation by CFD software of PHEONICS were also presented.The experimental results show good agreement with the corresponding numerical predictions.Based on numerical results,several conclusions can be drawn.Both the winglet height and the shape of vertex may influence heat transfer.Longitudinal vortex generators with the aspect ratio of 0.4 bring larger heat transfer enhancement than those with the aspect ration of 0.5 and 0.6.The rectangular winglet generators lead to higher Nusselt numbers than the delta winglet generators.But the comprehensive performance of rectangular pipe with rectangular winglet generators is lower than that with delta winglet generators.