Numerical simulation of flow and heat transfer in round-to-rectangular nozzles

Fluid flow and heat transfer in three-dimensional round-to-rectangular (RR) nozzles with regenerative cooling are analyzed numerically. In this analysis, the hot gas flow in the nozzle and the coolant flow in the cooling channels are taken into account, and the heat transfer processes of convection, radiation, and conduction are included. The characteristics of the RR nozzle are obtained. Effects of structure parameters on the flow and heat transfer of the RR nozzle are investigated. The parameters are round-to-rectangular transforming position, height-to-width ratio at the outlet, and arc radius of the outlet. The results indicate that the RR nozzle has different flow features than an axisymmetric nozzle; the heightto-width ratio of the exit plane has a significant influence on the flow and heat transfer in RR nozzles.