Investigation On Internal Flow And Heat Transfer Of Impingement-Film Cooling For The High-Temperature Components Of Gas Turbine

Increasing the turbine inlet temperature of gas turbine is an important way to improve the thermal efficiency of gas turbine,and with the continuous improvement of the turbine inlet temperature,efficient cooling technology has become the key to ensure the reliable operation of gas turbine.Impingement-film cooling is one of the advanced cooling methods used in modern gas turbine high-temperature components.The internal flow and heat transfer characteristics of the impingement-film double wall cooling and the leading edge impingement-film cooling are studied in this paper by means of transient thermal liquid crystal experiment and numerical simulation.The influence of Reynolds number,jet spacing ratio h/D and different crossflow arrangements on the impingement-film double wall cooling are analyzed,as well as the influence of Reynolds number and impingement hole position(e/D)on the leading edge impingement-film cooling.Moreover,the detailed flow structure in the impingement-film cooling system is obtained through numerical simulation,to reveal the heat transfer mechanism.The results show that the Nusselt number and the pressure loss of the impingement-film cooling increase with the increase of Reynolds number.For the impingement-film double wall cooling,the increase of jet spacing ratio h/D will reduce the Nusselt number.The pressure loss of the impingement-film double wall cooling with maximum crossflow decreases with the increase of h/D,while the change of h/D has little influence on the pressure loss of the case with zero crossflow.The impingement-film double wall cooling with zero crossflow shows higher Nusselt number than the case with maximum crossflow by 5.9%-19.3%.Meanwhile the zero crossflow case shows higher pressure loss by 2.8-3.3 times than the maximum crossflow case.For the leading edge impingement-film cooling,the averaged Nusselt number of the e/D=2 case is 2.2%higher than the e/D=0 case,and the pressure loss of the e/D=2 case is relatively lower by 2.9%than the e/D=0 case.