扭曲椭圆管强化换热与流动减阻特性的场协同分析

Field Synergy Analysis on Heat Transfer Enhancement and Flow Drag Reduction Characteristics in Twisted Oval Tubes

为了研究扭曲椭圆管管内强化换热性能,建立了扭曲比均为11.9条件下不同短长轴比的扭曲管几何模型,采用CFD技术对以水为流体的扭曲管及相应的管内进口段强化传热和流动减阻性能进行了数值模拟,获得各种工况的速度场、压力场及温度场,基于场协同原理对其速度与压力梯度的协同效果及速度与温度梯度的协同效果进行深入分析和比较,获得各种工况的强化传热和流动减阻性能随短长轴比变化的规律,探讨了影响扭曲椭圆管强化传热和流动减阻性能的影响因素及其影响机理,为扭曲椭圆管换热器工程应用的优化设计和科学研究提供可靠依据。

In order to study heat transfer performance of twisted oval tubes, a geometric model of twisted tubes with different short and long axis ratios under twist ratio of 11.9 was proposed using CFD （computational fluid dynamics）, and heat transfer enhancement and flow drag reduction problems at the entrance of the tube was studied. Velocity, pressure and temperature fields under different conditions were obtained. The synergy effects of velocity-pressure gradient and velocity-temperature gradient of twisted tubes were analysed using field synergy principle. The profiles of heat transfer enhancement and flow drag reduction with short and long axis ratios were obtained. The factors affecting heat transfer enhancement and flow resistance reduction of twisted oval tubes and their mechanisms were discussed. This study provides reliable data for optimal design and scientific research of twisted oval tube heat exchangers.