基于拉格朗日跟踪法的波纹流道流体特性研究

采用正交实验方法考察了具有不同结构参数的三维周期波纹流道中的流体性能,并采用Webb评价方法对其进行性能评价。比较了不同波纹宽度的波纹流道的阻力因子e_f、传热因子e_Nu和能效因子η的值,结果表明三者都随Re的增大而增大,波纹宽度最小时能效因子η最大。流体在波纹流道中垂直于主流方向的横截面上产生二次流,随着Re增大,二次流增强,阻力增大,温度边界层减薄,温度等值线分布变得不均匀,传热增强。采用拉格朗日粒子跟踪技术分析了不同Re下,流体粒子在波纹流道内的运动轨迹,绘制了不同周期出口流体粒子的庞加莱截面图,结果表明流体粒子在波纹流道中被反复拉伸和折叠,增加了流体粒子的接触面积,提高混合效率,强化了传热。

Research on Characteristics of Fluid Flow in Wavy Channel Based on Lagrange Tracking Method

The characteristics of fluid flow in the three-dimensional periodic wavy channels with different structure parameters are analyzed using orthogonal experiment method,and the comprehensive properties of the models are evaluated using Webb method.The frication factor e_f,the heat transfer factor eN_u and the energy efficiency factorηof wavy channels with different wavy width are compared, the results show that three of them increase with the Reynolds number increases,the energy efficiency factorηof the narrowest channel is the largest.The secondary flow is produced in the sections which are vertical to flow direction,with the Reynolds number increases,the secondary flow and the friction resistance both increase,the temperature boundary layers become thinner,the temperature contours become uneven and the heat transfer performance is enhanced.The particle trajectories in the channel under different Reynolds number are tracked using Lagrange tracking technology,the Poincare sections of different period outlet are draw,the results show that the particles are stretched and folded repeatedly in the wavy channel,the contact area and the mixing efficiency increase,and the heat transfer performance is enhanced.