Study on full-coverage film cooling on center cone at engine-realistic conditions

Abstract

Center cone locating at the rear portion of turbine is the key component of the integrated afterburner. Numerical studies were carried out to investigate full-coverage film cooling on center cone at engine-realistic conditions, and the effects of thermodynamic and geometric parameters on cooling effectiveness and aerodynamic loss were discussed in detail. The numerical model was validated by the infrared measured experiments. Two recirculation vortices were generated on the cone surface, and cause the reverse ejection of coolant. These two recirculation vortices were promoted by increasing blowing ratio, and mixed with each other as the blowing ratio reaches 3.0. Along the streamwise direction, cooling effectiveness decreases and reaches the minimum value at the tip of cone, which is very different from the flat-plate film cooling. Cooling effectiveness increases with the increases of blowing ratio, hole diameter and density ratio, but decreases with the increases of hole pitch and spacing. The discharge coefficient increases with the increases of hole diameter and inclination angle, but decreases with the increases of blowing ratio, hole pitch and spacing. Pure film cooling and double-wall cooling were also compared. The introduction of jet impingement cooling can generate higher cooling effectiveness, especially at low and medium blowing ratio, but causes the notable increase of pressure drop.