螺旋扭曲扁管管外传热性能数值模拟

为了研究螺旋扭曲扁管管外强化换热性能，采用周期性边界条件对螺旋扭曲扁管管外层流流动与换热性能进行了数值模拟和理论分析，并且与圆管进行比较。通过建立不同规格的螺旋扭曲扁管换热器几何模型，得出螺旋扭曲扁管的长短轴比a/b越大、螺距s越小，其管外传热性能就越好，强化传热综合性能评价因子就越大，与此同时，其流动阻力也会增大。随着Re数的增大，强化传热综合性能增强，但趋势变缓。该研究结果对螺旋扭曲扁管换热器的设计有一定的参考价值。

Numerical Simulation on Heat Transfer Performance of Laminar Flow Outside Twisted Oval Tube

ln order to research the heat transfer performance outside the twisted oval tube, the theoretical analysis andnumerical simulation were performed for the periodically fully developed fluid flow and heat transfer of the laminar flowoutside the twisted oval tube with periodic boundary condition. Different specifications geometric models of twisted ovaltubes including the aspect ratio a/b and the pitch s were established to analyze the performance outside the tube. Theresults show that the heat transfer performance of twisted oval tube increase with the increasing of a/b and decreasing ofs, and the flow resistance will also increase. The heat transfer performance of twisted oval tube increases with theincreasing of the reynolds number, and the trend slows down. The results have a certain reference value for the design oftwisted oval tube exchanger.