Design studies of turbine blade film cooling with unburned fuel in cross stream flow Conference

Thornburg, H, Sekar, B, Zelina, J et al. (2009). Design studies of turbine blade film cooling with unburned fuel in cross stream flow .

cited authors

  • Thornburg, H; Sekar, B; Zelina, J; Anderson, W; Polanka, MD; Lin, CX; Holder, RJ; Briones, AM; Stouffer, SD



  • Film cooling plays a critical role in providing effective thermal protection for components of modern gas turbine engines. A Reynolds-Averaged Navier-Stokes (RANS) approach is employed to simulate the complex turbulent reactive flow exhibited by film cooling flows emanating from a surface. The widely used SST k-ω turbulence model is used to model the turbulent flow. A simplified two-step propane-air reaction scheme has been employed to model the combustion process and study the underlying physics of mixing between film cooling and cross stream flow driving secondary combustion. The Eddy-dissipation concept (EDC) approach is used to account for the turbulence-chemistry interaction. The three-dimensional geometry is modeled using a hybrid mesh. The reacting flow field and the resulting film cooling effectiveness are predicted for circular, angled circular, and fanned film hole geometry for two equivalence ratios, one blowing ratio, and both air and N2 film cooling. Numerical results between air and N2 film cooling generally agree well with experimental data in terms of relative temperature change, non-dimensionalized with respect to the N2 film temperature. Results indicate that hole geometry plays a key role in the effectiveness of the film cooling design. Film cooling provided by the normal circular hole is considerably lower than that provided by the angled and fanned hole for both lean and in rich conditions. Air injection feeds secondary combustion that substantially increases the wall temperature on the flat surface for a considerable distance downstream of the hole. However, the shaped hole produces a larger effective film area in the immediate vicinity of the cooling hole both axially and laterally when compared to the normal circular and angled circular configurations. For fuel rich conditions a distinct hot area downstream of the coolant hole generated by the secondary combustion feed by coolant air injection has been predicted. This results in negative cooling effectiveness in certain areas of the flat surface, specifically for the shaped hole. The N2 coolant air injection provides no O2 to feed secondary combustion for the unburned fuel exiting the combustor at high equivalence ratios. Copyright © 2009 by the American Institute of Aeronautics and Astronautics, Inc.

publication date

  • December 1, 2009

International Standard Book Number (ISBN) 13