Transonic Film-Cooling Investigations: Effects of Hole Shapes and Orientations

Abstract

The emphasis of the present study is to understand the effects of various flowfield and geometrical parameters in the nearfield region of a scaled-up film-cooling hole on a flat test plate. The effect of these different parameters on adiabatic wall effectivenesses, heat transfer coefficients, discharge coefficients and the near-hole velocity field will be addressed. The geometrical parameters of concern include several angles of inclination and rotation of a cylindrical film-cooling hole and two different hole shapes — a fanshaped hole and a laidback fanshaped hole. The fluid dynamic parameters include both the internal and external Mach number as well as the mainstream-to-coolant ratios of total temperature, velocity, mass flux, and momentum flux. In particular, the interaction of a film-cooling jet being injected into a transonic mainstream will be studied. This paper includes a detailed description of the test rig design as well as the measuring techniques. Firstly, tests revealing the operability of the test rig will be discussed. Finally, an outlook of the comprehensive experimental and numerical program will be given.

Film cooling effectiveness: Comparison of adiabatic and conjugate heat transfer CFD models

“…A complete description of their experimental facility, located at the University of Karlsruhe, including the test section, and instrumentation used in acquiring the reported data, is given in [8,10]. They conducted a detailed measurements of adiabatic film cooling effectiveness for injection from single scaled-up filmcooling hole geometries.…”

“…Wittig et al [8], Thole et al. [9] and Gritsch et al [10] studied the effect of film hole geometry on the film cooling flowfield.…”

Film Cooling Effectiveness From a Single Scaled-Up Fan-Shaped Hole: A CFD Simulation of Adiabatic and Conjugate Heat Transfer Models

“…We used the data reported in the open literature by Gritsch et al [10]. A complete description of their experimental facility, located at the University of Karlsruhe, including the test section, and instrumentation used in acquiring the reported data, is given in [8,10]. They conducted a detailed measurements of adiabatic film cooling effectiveness for injection from single scaled-up film-cooling hole geometries.…”

“…Wittig et al [8], Thole et al [9] and Gritsch et al [10] studied the effect of film hole geometry on the film cooling flowfield. They provided measurements for the flowfield and the film cooling effectiveness downstream of a cylindrical, a laterally expanded, and a laterally forward expanded filmcooling hole.…”

Numerical study on discharge coefficients of a jet in crossflow

“…When the flow turns to supersonic due to the effect of the shock wave, the flow characteristics in the vicinity of film hole change remarkably. According to the experimental results by Witting [30], under free-stream Mach number of 1.2, shock waves can be formed in the interacting region between the coolant and mainstream above the hole. Ligrani et al [31] studied the effects of shock waves on film cooling; the authors show that the shocks give negative influence on discharge coefficient as well as the film cooling effectiveness along the streamwise direction.…”