The influences of the header geometry on hydrocarbon fuel flow distribution in compact parallel channels

Parallel cooling channels have been a commonly seen configuration in advanced aero-engines, for example, the scramjet. However, the mal-distribution of hydrocarbon fuel in cooling channels may cause waste of fuel cooling capacity and even over-temperature of the engine structure. In order to ensure the cooling effect and the structure safety, the header geometry should be designed carefully. In this work, the parametric analysis of the header geometries was carried out under the limitations of compact geometry and high temperature environment in scramjet cooling channels. A 3D numerical model of the hydrocarbon fuel flow and heat transfer under supercritical pressure in parallel channels was developed. The flow area ratio of the inlet and outlet headers, feeding tube and header aspect ratio were selected as the main parameters of the parametric analysis. The results indicate that proper design of the headers could improve the uniformity of flow distribution and cooling effects obviously. Local optimums of flow area of the inlet/outlet headers and header aspect ratio exist. The outlet header should be larger which contains the heated fuel. Proper feeding tube improves the flow distribution by the injection effect in the header. The header aspect ratio performs better when the wet perimeter is smaller. The results offer possible advice for the header design limited by compact size and high temperature environment.