Research On Impingement/Film Cooling Technique Of Triple-Swirler Combustor

On the background of aero-engine liner cooling technique, the present work focuses onimpingement/film cooling structure with guide ring. The effects of the density flow ratio, the ratio ofguide ring length to the diameter of jet hole, the ratio of jet impingement distance to the diameter ofthe jet hole, the ratio of the axial distance between jet hole and the root of guide ring on coolingefficiency were revealed both numerically and experimentally.The results show that the cooling efficiency increases with the increase of the density flow ratio.With the increase of the ratio of guide ring length to the diameter of jet hole, the cooling efficiencyincreases, however, accompanying by increase in the weight of combustor liner will be added. Thedecrease of the ratio of jet impingement distance to the diameter of the jet hole is favorable forcooling efficiency, but too small distance would affect the out flow of film. The ratio of the axialdistance between jet hole and the root of guide ring has little influence on cooling efficiency.Based on the results above, an impingement/film cooling scheme and a multi-holes coolingscheme were designed and evaluated in a triple-swirler combustor model. The effect of the inlettemperature, the inlet velocity, the fuel/air ratio, and the cooling geometry on combustor liner walltemperature distribution were obtained. By increasing the inlet temperature, fuel/air ratio ordecreasing the inlet velocity, the wall temperature rises. An optimized cooling scheme was thenproposed and tested by numerical simulation and experimental study, the results show that walltemperature can be kept in an accepted range in spite of the cooling air’s reduction.