【摘要】 通过计算流体力学方法对圆形、椭圆形和矩形截面的螺旋管在湍流工况下的流动及传热性能进行模拟,分析了不同截面螺旋管内流体的速度场、温度场分布特征和场协同性能。结果表明,不同截面形状的螺旋管内均产生了二次流,二次流速度平均达到主流速度的2.7%~4.7%,二次流影响了场协同性能,进而影响了传热性能。圆形截面螺旋管综合传热性能最佳,椭圆形和矩形的螺旋管中,沿螺旋管螺旋线径向方向和轴向方向尺寸比值大的综合传热性能更好。随着Re的增大,场协同对于强化传热的影响逐渐减小,主流的湍流进一步成为强化传热主导因素。更多还原

【Abstract】 Numerical simulations were conducted to investigate the flow and heat transfer performance in helically coiled tubes with circular,ellipse and rectangle cross-section using CFD.The velocity field,the temperature field and the fields synergy in helically coiled tubes with different cross-sections were analyzed.The results showed that secondary flow in different-cross-section tube affects the temperature field and the fields synergy and then improves heat transfer performance.The heat transfer of helically tube with circular cross-section was the best.For the tube with ellipse and rectangle cross-sections,the one with bigger size ratio of radial direction of helix to axial direction had better performance.With the increase of Reynolds number,the influence of the fields synergy on heat transfer declined while the influence of turbulent flow raised.更多还原