Numerical investigation of flow and heat transfer behavior on vortex cooling with an optimal convergent coolant chamber for different nozzle aspect ratio arrangement mode

Abstract

A computational model including convergent coolant chamber, nozzles and vortex chamber is established. The vortex cooling flow and thermal exchange features are investigated under different nozzle aspect ratio arrangement mode based on an optimal convergent coolant chamber. The nozzle aspect ratio arrangement mode consists of two parts, namely eight nozzle aspect ratio sizes and three kinds of nozzle aspect ratio axial variations. Results indicate that the erosion velocity increases due to the smaller windward area with the increasing nozzle size. The convergent coolant chamber makes the mass flow and pressure increases, the reflux phenomenon appears. And the increasing nozzle size leads to the first increase and then decrease with high pressure and Nusselt number area. For the nozzle aspect ratio arranged from high to low, the airflow stiffness and turbulent kinetic energy at the sixth nozzle are the largest, the thermal transfer feature enhances. For the nozzle aspect ratio arranged from low to high, the airflow impact strength and heat exchange characteristic decreases. But the drag coefficient is minimal that has a positive effect on flow features. The thermal exchange capacity is the highest with the nozzle aspect ratio 2.0. Consequently, this study can provide reference for gas turbine design.