【摘要】 通过实验与三维数值模拟相结合的方法,对内置螺旋线圈平行平板通道的流动及传热特性进行了研究,发现相对于无扰流填充物的平板通道,螺旋线圈的应用能够显著地强化传热,相同Re数下Nu数增幅为29%~141%,相应地阻力系数增幅为26%~175%。数值模拟的结果显示,流体受螺旋线圈的诱导可产生多纵向涡流动,增强了速度在垂直于壁面方向的分量,同时导致温度场发生明显改变,使得速度场与温度梯度场的协同性能得到提升,从而强化了传热。在700<Re<7 500的范围内,通过对流动换热综合性能参数的比较发现,在Re数较小时,强化传热后换热效果的提升要大于流动阻力的增加,而在Re数较高时则相反。更多还原

【Abstract】 The flow and heat transfer characteristics of parallel flat plate channel with spiral coil inserts were studied experimentally and numerically.It is found that the application of spiral coil inserts can effectively enhance heat transfer compared with the flat plate channel without spiral coil inserts.With the same Reynolds number,the heat transfer is enhanced 29%~141% while the flow restriction is increased 26%~175%.The numerical results indicate that multi-longitudinal vortices are induced by the spiral coil inserts,which enhanced the velocity component that vertical to the channel wall and caused a remarkable change in temperature field.Consequently,the coordination between flow and temperature fields is improved and the heat transfer is enhanced.With Reynolds number between 700 and 7 500,the comparison between different overall performance evaluation parameter shows that the heat transfer enhancement is larger than the flow resistance increase at lower Reynolds number,but on the contrary at higher Reynolds number.更多还原