Numerical study on flow and heat transfer behavior of vortex and film composite cooling

Abstract

The complete vortex and film composite cooling model is established to study the flow and heat transfer behavior. Influences of coolant Reynolds number, film hole diameter and inject angle on vortex and film composite cooling property are thoroughly discussed. Results show that the vortex nozzle coolant mass flux increases along the vortex chamber axial direction, while the film hole coolant mass flux and blowing ratio decrease along the vortex chamber axial direction. The internal heat transfer intensity will increase along the vortex chamber axial direction. The adiabatic film cooling efficiency decreases downstream due to counter rotating vortex pairs (CRVP) lift off wall effects. The coolant rotational velocity in vortex chamber increases with the increasing Reynolds number, thus leading to obvious heat transfer enhancement. An increase in Reynolds number results in an increase in CVRP intensity, hence the adiabatic film cooling efficiency will turn lower. The coolant rotational velocity and internal heat transfer intensity will decrease with the increase of film hole diameter. The CRVP intensity and film hole jet coolant mass flux increases with the increasing film hole diameter, leading to an increase in adiabatic film cooling efficiency. The rotational coolant flow and heat transfer intensity are not sensitive to inject angle. As the inject angle increases, the CRVP intensity changes little and the inject coolant owns larger inclined angle with gas mainstream flow, therefore the adiabatic film cooling efficiency will increase.