Investigation of the flow-heat-vortex mechanism in hot, coolant and delivery channels in film cooling under strongly-coupled boundary conditions using direct numerical simulation

Abstract

The research investigated the flow dynamics, heat transfer, and vortices in film cooling using direct numerical simulation (DNS) with various blowing ratios (Br = 0.63, 0.86, 1.18) and Reynolds numbers (Re = 1000, 1000, 500) at an injection angle of α = 20°. The strongly-coupled (SCP) boundary conditions were applied to solve the transient governing equations including to mass and momentum conservations, thermal convection and heat conduction. Jetting effects in the delivery channel were studied by the DNS method in the environment of both hot and coolant channels. Distinctive vortex structures, including the horseshoe and hairpin vortices inside the delivery channel, were successfully identified with the recirculation and high-velocity stripes inside the channel. The heat-transfer mechanisms resulting from the vortices in hot channel highlighted the presence of kidney-shaped and reverse-kidney-shaped vortices impacting the Nusselt number (Nu) and comprehensive cooling effectiveness, which was enabled by the state-of-the-art VI method of Liutex.

Keywords:

• Direct Numerical Simulation
• Film Cooling
• Heat Transfer
• Kidney-shaped Vortex
• Liutex

Additional information

Funding

The research was financially supported by the Shanghai Municipal Education Commission (Grant No. AR960) and the Shanghai Municipal Science and Technology Commission (Grant No. 20JC1413700).