外涵空气燃油双工质换热器燃油管结构流动换热特性研究

Research on Flow and Heat Transfer Characteristics of Fuel Pipe Structure in a Bypass Air and Fuel Dual-fuild Heat Exchanger

针对涡扇航空发动机外涵和引气的实际气动参数,以及燃油流量等参数,通过数值模拟研究了双工质换热器内燃油管数目、直径和截面形状对燃油和引气流动换热性能的影响。研究结果表明,在设定的参数范围内,增加燃油管数目能够在有效地提高整体换热效果的同时,降低燃油流动阻力;燃油管总流通截面积是影响燃油流动阻力的主要因素,当燃油管流通截面积相同,燃油管数目的变化不会影响燃油流动压降;燃油管流通截面积相同,管型对燃油流动压降影响很小,但就换热性能而言,跑道形管道换热效果最好,椭圆形管次之,圆形管最差。

A series of numerical simulations were performed to investigate the effects of main geometric parameters(including the number,diameter and cross-sectional shape of the fuel pipe)on flow and heat transfer performance of fuel and bleeding air for a specific bypass air and fuel dual-fluid heat exchanger,under representative bypass and bleeding flow conditions and fuel mass flow of an turbofan aeroengine.Among the current ranges of geometric parameters,it is found that increasing the number of fuel pipes can effectively improve the overall heat transfer effect and reduce the fuel flow resistance;the total cross-sectional area of the fuel pipe is the main factor affecting the fuel flow resistance.The flow crosssection area is the same,and the change in the number of fuel pipes will not affect the pressure drop of the fuel flow;when the flow crosssection area of the fuel pipe is the same,the tube shape has little effect on the fuel flow pressure drop.However,in terms of heat transfer performance,runway-type pipes have the best heat transfer effect,elliptical pipes take second place,and round pipes have the worst.