Large eddy simulations (LES) were performed to investigate film cooling of a flat plate, where the cooling jets issued from a plenum through one row of circular holes of diameter D and length 4.7D that are inclined at 35 deg relative to the plate. The focus is on understanding the turbulent structure of the film-cooling jet and the film-cooling effectiveness. Parameters studied include blowing ratio (BR = 0.5 and 1.0) and density ratio (DR = 1.1 and 1.6). Also, two different boundary layers (BL) upstream of the film-cooling hole were investigated—one in which a laminar BL was tripped to become turbulent from near the leading edge of the flat plate, and another in which a mean turbulent BL is prescribed directly. The wall-resolved LES solutions generated were validated by comparing its time-averaged values with data from PIV and thermal measurements. Results obtained show that having an upstream BL that does not have turbulent fluctuations enhances the cooling effectiveness significantly at low velocity ratios (VR) when compared to an upstream BL that resolved the turbulent fluctuations. However, these differences diminish at higher VRs. Instantaneous flow reveals a bifurcation in the jet vorticity as it exits the hole at low VRs, one branch forming the shear-layer vortex, while the other forms the counter-rotating vortex pair (CRVP). At higher VRs, the shear layer vorticity is found to reverse direction, changing the nature of the turbulence and the heat transfer. Results obtained also show the strength and structure of the turbulence in the film-cooling jet to be strongly correlated to VR.
Skip Nav Destination
Article navigation
October 2018
Research-Article
Effects of Density and Blowing Ratios on the Turbulent Structure and Effectiveness of Film Cooling
Zachary T. Stratton,
Zachary T. Stratton
School of Aeronautics and Astronautics,
Purdue University,
West Lafayette, IN 47907
e-mail: zstratto@purdue.edu
Purdue University,
West Lafayette, IN 47907
e-mail: zstratto@purdue.edu
Search for other works by this author on:
Tom I-P. Shih
Tom I-P. Shih
School of Aeronautics and Astronautics,
Purdue University,
West Lafayette, IN 47907
Purdue University,
West Lafayette, IN 47907
Search for other works by this author on:
Zachary T. Stratton
School of Aeronautics and Astronautics,
Purdue University,
West Lafayette, IN 47907
e-mail: zstratto@purdue.edu
Purdue University,
West Lafayette, IN 47907
e-mail: zstratto@purdue.edu
Tom I-P. Shih
School of Aeronautics and Astronautics,
Purdue University,
West Lafayette, IN 47907
Purdue University,
West Lafayette, IN 47907
Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the JOURNAL OF TURBOMACHINERY. Manuscript received August 9, 2018; final manuscript received August 16, 2018; published online September 28, 2018. Editor: Kenneth Hall.
J. Turbomach. Oct 2018, 140(10): 101007 (12 pages)
Published Online: September 28, 2018
Article history
Received:
August 9, 2018
Revised:
August 16, 2018
Citation
Stratton, Z. T., and Shih, T. I. (September 28, 2018). "Effects of Density and Blowing Ratios on the Turbulent Structure and Effectiveness of Film Cooling." ASME. J. Turbomach. October 2018; 140(10): 101007. https://doi.org/10.1115/1.4041218
Download citation file:
Get Email Alerts
Evaluating Thin-Film Thermocouple Performance on Additively Manufactured Turbine Airfoils
J. Turbomach (July 2025)
Thermohydraulic Performance and Flow Structures of Diamond Pyramid Arrays
J. Turbomach (July 2025)
Related Articles
A Detailed Analysis of Film Cooling Physics: Part III— Streamwise Injection With Shaped Holes
J. Turbomach (January,2000)
The Dynamics of the Horseshoe Vortex and Associated Endwall Heat Transfer—Part I: Temporal Behavior
J. Turbomach (October,2006)
Coupling of Volumetric Flowfield and Surface Effectiveness Measurements for Flat-Plate Film Cooling With Cylindrical Holes Using Tomographic Particle Image Velocimetry and Pressure-Sensitive Paint
J. Thermal Sci. Eng. Appl (June,2023)
Large Eddy Simulations on Fan Shaped Film Cooling Hole With Upstream Boundary Layer Turbulence Effect Generated by Trip Strip
J. Thermal Sci. Eng. Appl (March,2022)
Related Proceedings Papers
Related Chapters
Cavitating Structures at Inception in Turbulent Shear Flow
Proceedings of the 10th International Symposium on Cavitation (CAV2018)
Control and Operational Performance
Closed-Cycle Gas Turbines: Operating Experience and Future Potential
Introduction
Design and Analysis of Centrifugal Compressors