串列双颗粒绕流传热大涡模拟研究

Investigation of Flow and Heat Transfer Past Two End-to-end Particles With Smooth or Dimpled Surface by Large Eddy Simulation

本文采用大涡模拟的方法对串列双颗粒绕流的流动和换热特性进行了研究,分析了前后颗粒的阻力系数和努塞尔数随时间变化的关系,此外,对比分析了光滑双颗粒和凹坑双颗粒的流动和换热特性。研究发现不同表面结构的双颗粒绕流时的流动和换热特性存在明显差异,且相比与光滑双颗粒,凹坑双颗粒的前后颗粒分别减小18.27%和3.08%的流动阻力,同时换热性能分别提升14.26%和7.77%。凹坑结构呈现出更优异的流动和换热性能。

In the present study,the air flow and heat transfer past two end-to-end spheres with smooth and dimpled surface were investigated by large eddy simulation.The drag coefficient and Nusselt number of the before and after particle are analyzed as the time changes.Moreover,the flow and heat transfer characteristics of smooth and dimpled double particles were compared.It is found that there are significant differences in the flow and heat transfer performance with different surface structures.Compared with the two end-to-end particles with smooth surface,the drag coefficient of the front and rear particles with dimpled structure decreases by 18.27%and 3.08%,respectively.Meanwhile,the heat transfer performance is improved by 14.25%and 7.78%.The dimpled structure shows better flow and heat transfer performance.