翅片椭圆管偏斜角对风洞换热器性能的影响

Effect of deflection angles on performances of finned oval tube heat exch an ger applied to wind tunnel

基于某风洞换热器结构,建立了翅片椭圆管换热器的三维模型。研究了翅片椭圆管的偏斜角α对换热器传热、压降特性及出口空气温度场均匀性的影响。由于换热器的当量直径较小,雷诺数Re的变化范围为3 500~5 200。数值模拟结果表明:椭圆管偏斜角的改变影响了换热管尾涡的流向,从而改变了换热器的性能;随着椭圆管偏斜角的增大,换热性能增大的趋势减缓,而压力损失增大的趋势逐渐加剧;当椭圆管偏斜10°时,换热器不仅具有较优的整体性能,而且具有较优的出口空气温度均匀性。

Based on the structure of a wind tunnel heat exchanger,establishes a three-dimensional model of finned oval tube heat exchanger.Investigates the effects of deflection angles of finned oval tubes on heat t*ransfer pressure drop characteristics and uniformity of outlet air temperature field respectively.Because the equivalent diameter of the heat exchanger is smalL the range of Re value is 3500 to 5200.The numerical simulation results show that the change of deflection angle of the tube affects the flow direction of the wake vortex,thereby changes the performance of the heat exchanger.With the increase of deflection angle of oval tube,the increasing trend of heat transfer performance slows down,while the pressure loss increases gradually.When the oval tube is deflected by 10 degrees»the heat exchanger not only has better overall performance,but also has better outlet air temperature uniformity.