高粘度流体在三维内肋管中层流强化传热性能研究

摘要

以润滑油为工质，采用正交原理试验设计方法，对高粘度流体在叉排列三维内肋管中的流动和传热性能进行了研究。结果表明：离散的三维内肋结构能够促进高粘度流体在较低的雷诺数下完成从层流向湍流的转变。说明在高粘度流体的换热问题中，采用三维内肋管可以有效促进流态转变，并因此获得明显的传热强化效果；对试验数据采用最小二乘法进行多元线性回归，获得了三维内肋管中高粘度流体在层流区的流阻和换热准则方程式；根据Webb定义的热力性能系数，作为强化传热性能的判断指标，得到了性能最优的三维肋结构组合，为结构优化指出了方向。%Characters of flow resistance and heat transfer of high viscosity fluid flowing within three-dimensional internally crossing-finned tubes were investigated with orthogonal experimental method.Experimental results showed that obvious low criti-cal Reynolds numbers were attained within all the experimental tubes,which indicated that structure of separated three dimen-sional internally crossing-finned tubes can accelerate flow transformation from laminar to turbulent.It can enhance heat transfer performance of high viscosity fluid in engineering practical use.Empirical equations on flow resistance and heat transfer of lami-nar flow within three dimensional internally crossing-finned tubes were obtained with linear minimal dual multiply method.The optimal configurations of three dimensional internally crossing-finned tube for the highest value of thermal performance factor were also obtained according to these experimental results.