Effects of aspect ratio on the turbulent heat transfer of regenerative cooling passage in a liquid rocket engine

Turbulent flows and related heat transfer in a regenerative cooling passage of liquid rocket engine are investigated by turbulence models. At a constant mass flow rate, threedimensional characteristics of flow and heat transfer are studied by changing the aspect ratio under constant or variable heat flux conditions. The cooling passage shows different flow structures, which cannot be found in a straight duct, because the heated wall has a convex-concave-convex curvature. So, the streamwise velocity and secondary flows are varied by the geometrical feature of curvature inversion. From these characteristics the thermal field in the cooling passage is discussed depending on the variation of crosssectional area and the aspect ratio. Also, the influences of aspect ratio coupled to the thermal boundary condition are investigated. Finally, the geometric effects on the local heat transfer and the change of flow structure are scrutinized.