Session: 15-01 Jet Impingement

Paper Number: 79362

79362 - Heat Transfer and Pressure Loss Correlations for Leading Edge, Jet Impingement Using Racetrack-Shaped Jets With Filleted Edges 

This paper presents an experimental investigation of heat transfer and pressure loss for leading edge jet impingement using racetrack shaped jets.  The majority of literature considers jet impingement using square edged orifices to create the jets.  However, for gas turbine cooling applications, the edge of jet orifices generally have some degree of filleting (or rounding) along the edges.  The rounding may be a result of casting the airfoils or material wear due to long-term operation.  In addition, within the engine, it is likely the jet orifice is not perfectly round.  Engineers need data under realistic engine configurations to improve the utilization of coolant while adequately protecting the airfoil.  The current experimental study is a parametric investigation of heat transfer and pressure loss for leading edge jet impingement.  In this investigation, the effects of jet Reynolds number (Re = 10,000 – 100,000), jet – to – jet spacing (s/d = 2 – 8), jet – to – target surface spacing (z/d = 2 – 4), surface curvature (D/d = 2.67 – 5.33), and jet fillet – to – jet plate thickness (r/l = 0.18 – 0.5) are each considered.  The inclusion of the fillet at both the inlet and outlet of the jet plate yields reduced heat transfer compared to the square edged jets.  However, the fillets significantly improve the discharge coefficients associated with the racetrack shaped orifices.  With the extensive testing completed in this study, design correlations have been developed to predict the surface Nusselt number and discharge coefficients including the geometrical parameters investigated in this study.  The newly developed correlations accurately capture the geometrical effects with a deviation of the current experimental data being approximately 10% and 19% for the Nusselt numbers and discharge coefficients, respectively.  Engine designers can predict the level of heat transfer and pressure loss for leading edge jet impingement using these correlations.

Presenting Author: Ritwik Vijaykumar Kulkarni Texas A&M University

Presenting Author Biography: Ritwik Vijaykumar Kulkarni is a graduate alumnus of Texas A&M University and have worked with Professor Lesley Wright at Texas A&M University in College Station, Texas. His research focusses on the jet impingement cooling technique in the gas turbine leading edge and development of experimental correlations for racetrack shaped jets. Prior pursuing graduate degree, his internship experience at Indian Institute of Technology Bombay includes experimental study of film cooling in the mid-chord section and numerical modelling of internal channels.

Authors:

Ritwik Vijaykumar Kulkarni Texas A&M University
Lesley Wright Texas A&M University - College Station