On heat transfer and flow characteristics of jets impinging onto concave surface with varying bleeding arrangements

Abstract

Purpose The purpose of this study is to investigate the effects of film holes’ arrangements and jet Reynolds number on flow structure and heat transfer characteristics of jet impingement conjugated with film cooling in a semicylinder double wall channel. Design/methodology/approach Numerical simulations are used in this research. Streamlines on different sections, skin-friction lines, velocity, wall shear stress and turbulent kinetic energy contours near the concave target wall and vortices in the double channel are presented. Local Nusselt number contours and surface averaged Nusselt numbers are also obtained. Topology analysis is applied to further understand the fluid flow and is used in analyzing the heat transfer characteristics. Findings It is found that the arrangement of side films positioned far from the center jets helps to enhance the flow disturbance and heat transfer behind the film holes. The heat transfer uniformity for the case of 55° films arrangement angle is most improved and the thermal performance is the highest in this study. Originality/value The film holes’ arrangements effects on fluid flow and heat transfer in an impingement cooled concave channel are conducted. The flow structures in the channel and flow characteristics near target by topology pictures are first obtained for the confined film cooled impingement cases. The heat transfer distributions are analyzed with the flow characteristics. The highest heat transfer uniformity and thermal performance situation is obtained in present work.

Mini-channel embedded film cooled flat plate: conjugate heat transfer analysis and enhancement study

“…External cooling, in which coolant ejected from a film hole develops a protecting cover of coolant near the outer wall and protects the blade material. Internal cooling, such as impingement and convection cooling (Won et al, 2004;Luo et al, 2016;Singh et al, 2021aSingh et al, , 2021bQiu et al, 2021;Yan et al, 2022), is the main blade cooling technique. Turbulators are also used in the cooling passage to improve cooling performance.…”