The flow rate distribution of hydrocarbon fuel in parallel channels with different cross section shapes

Abstract

When pursuing higher flight Mach number, engine cooling arises to become more and more important in advanced aero-engines. Taking the regenerative cooling of SCRamjet for example, the fuel flow mal-distribution in parallel cooling channels may cause severe fuel cooling capacity waste and even over-temperature of the engine wall. In order to ensure the fuel cooling capacity and structure safety, the geometry of channels should be properly designed to make best use of the fuel cooling capacity, in which the cross section shape influences the flow and heat transfer greatly. Thus, in this work, a 3D numerical model of flow and heat transfer in parallel cooling channels was developed and validated with experimental data. The effects of channel cross section shape on the distribution of flow rate and fuel cooling capacity were studied. Besides the typical rectangle, other three different cross section shapes: circle, trapezoid and triangle, were also studied and compared. The results indicate that the triangular shape is best in heat transfer performance and flow distribution. The trapezoidal shape channels show good performance, too. The influence of the heat flux direction on flow distribution was also analyzed to present the effects of different layouts of the atypical-shape-channels. The cross section shape is proved to be an effective design factor in improving the flow distribution and the fuel cooling capacity utilization.