波浪管内流场与传热及阻力特性数值模拟

参照波浪管单管换热的实验数据，选用Fluent软件中的不同湍流模型和壁面处理方法，对波浪管换热器的换热系数和压降进行计算，通过比较计算结果，确定可用于波浪管内流动传热特性模拟的计算方法。在此基础上，进一步分析流体在波浪管内部的流场结构和传热特性。分析结果表明：RNG k-ε模型配合增强壁面处理方法得到的计算结果与实验值最为接近；与直管相比，波浪管的换热系数和阻力系数的增加幅度在低Re下较大，而在高Re下较小，其中换热系数和阻力系数增加幅度最大的位置均出现在各弧段交接处，即曲率反向的位置。计算结果可为强化传热管设计及其优化提供支撑。

Numerical Study on Flow Field With Heat Transfer and Flow Resistance in Wavy Tube

The heat transfer and pressure drop characteristics of wavy tube heat exchanger were investigated numerically with commercial computation software Fluent. Different turbulence models and near-wall treatments were studied, and the results were compared with experimental data to determine the most appropriate scheme for simulating the hydrodynamics and heat transfer in wavy tube heat exchanger. On the basis of this, further studies on the structure of flow field and the heat transfer characteristics of wavy tube were done. It can be concluded that RNG k-ε model combined with enhanced wall treatment gives the closest result to the experimental date compared to other schemes. Compared to the straight tube, it can be seen that the increase of the heat transfer coefficient and the frictional coefficient is substantial in low Re while small in high Re, and the positions with the highest heat transfer coefficient and the highest pressure drop are both located at the junction of arc segments, where curvature changes direction. The simulation results can support the future study on design and optimization of the enhanced heat transfer tubes.