Adiabatic Effectiveness Measurements of Film Cooling in Supersonic Flow
Document Type
Conference Proceeding
Publication Date
6-16-2025
Abstract
High temperature, high supersonic Mach number flows can be encountered in different innovative propulsion systems configurations such as Rotating Detonation Combustors (RDCs) and scramjets, requiring the use of film cooling for the thermal management. For this reason, a clear understanding of the performance of film cooling in supersonic flow is paramount. This experimental study investigated the performance of film cooling in a supersonic flow at Mach 1.65 comparing it with subsonic flow operations at Mach 0.3. Adiabatic effectiveness measurements were performed using Pressure Sensitive Paint. This technique also provided pressure field maps, useful to enhance the understanding of the physical phenomena under investigation. Additionally, time-averaged schlieren images enabled the visualization of the flow field morphology and understanding of the underlying physics. Cylindrical holes both aligned with the flow and with a 30 degrees compound angle and 7-7-7 fan-shaped holes aligned with the flow were considered. The results indicated performance improvements in both centerline and laterally averaged adiabatic effectiveness induced by the action of the oblique shock forming upstream of the hole. The same shock is responsible for modifying the shape of the adiabatic effectiveness contour, determining a higher peak along the centerline which linearly decreases outward instead of showing the more typical bell shape. The fan-shaped holes outperform the other holes at any blowing ratio (BR) over 0.8 for supersonic main flow operations. Performance of cylindrical holes in supersonic flow follow the trend typically encountered in subsonic flows while also bringing the peak in adiabatic effectiveness upstream and closer to the hole exit.
Source Publication
ASME Turbo Expo 2025: Turbomachinery Technical Conference and Exposition
Recommended Citation
Sandri, U, Polanka, MD, Picchi, A, Andreini, A, & Facchini, B. "Adiabatic Effectiveness Measurements of Film Cooling in Supersonic Flow." Proceedings of the ASME Turbo Expo 2025: Turbomachinery Technical Conference and Exposition. Volume 5: Energy Storage; Fans and Blowers; Heat Transfer: Combustors; Heat Transfer: Film Cooling. Memphis, Tennessee, USA. June 16–20, 2025. V005T12A013. ASME. https://doi.org/10.1115/GT2025-152900
Comments
This conference paper is published by ASME and is accessible by subscription or purchase using the DOI link below.
ASME Paper No: GT2025-152900