TITLE:
Hybrid RANS-LES of Shaped Hole Film Cooling on an Adiabatic Flat Plate at Low Reynolds Number
AUTHORS:
Michael Boehler, Akshay Sudesh, Mark Turner
KEYWORDS:
Film Cooling, Large Eddy Simulation, Detached-Eddy Simulation, Stress-Blended Eddy Simulation, Laidback Fan-Shaped Cooling Hole, Film Cooling Effectiveness
JOURNAL NAME:
Open Journal of Fluid Dynamics,
Vol.10 No.4,
December
4,
2020
ABSTRACT: Hybrid RANS-LES methods offer a means of reducing computational cost and setup time to simulate transitional flows. Several methods are evaluated in ANSYS CFX, including Scale-Adaptive Simulation (SAS), Shielded Detached Eddy Simulation (SDES), Stress-Blended Eddy Simulation (SBES), and Zonal Large Eddy Simulation (ZLES), along with a no-model laminar simulation. Each is used to simulate an adiabatic flat plate film cooling experiment of a shaped hole at low Reynolds number. Adiabatic effectiveness is calculated for Blowing Ratio (BR) = 1.5 and Density Ratio (DR) = 1.5. The ZLES method and laminar simulation most accurately match experimental lateral-average adiabatic effectiveness along the streamwise direction from the trailing edge of the hole to 35 hole diameters downstream of the hole (X/D = 0 to X/D = 35), with RMS deviations of 5.1% and 4.2%, and maximum deviations of 8% and 11%, respectively. The accuracy of these models is attributed to the resolution of turbulent structures in not only the mixing region but in the upstream boundary layer as well, where the other methods utilize RANS and do not switch to LES.