Research On Flow And Heat Tranfer Characteristics Of Cooling Structure In High Pressure Turbine Shroud

High pressure turbine shroud is one of the most important parts of gas turbine engine, whichis used to support the turbine casing and prevent it from hot gas. The internal cooling structure ofHPT shroud is the key to keep turbine working safely, thus numerical and experimentalinvestigations are carried out in this thesis to study the flow and heat transfer characteristics of thecooling structure in HPT shroud.Firstly, three-dimensional numerical simulations were applied to study the basic coolingscheme. The flow field and pressure loss in the complicated cooling structures of HPT shroudwere concluded. Additional calculations were carried out to investigate the effect of the deflexionangle of hot gas, which was induced by the leakage flow in turbine blade tip. It was found that thefilm cooling in HPT shroud was affected by this angle greatly and better cooling coefficient wasachieved with the negative sixty degrees angle.Then more calculations were applied, which focus on the film cooling structure in HPTshroud. The orthogonal design method was used to determine the numerical parameters, and thehole diameter, film hole streamline distance and the spanwise distance were studied. The resultsshow that high cooling coefficient is project of D=0.8mm、S=7mm、P valus constant、intervalconfiguration when blowing rate is less than2.0and project of D=0.6mm、S valus constant、P=7mm、interval configuration when blowing rate is2.0. Among these parameters, the holediameter is the most sensitive and the spanwise distance is the secondly sensitive parameter.Furthermore experiments were carried out to study the film cooling coefficient. Blowing rateM（0.6～2.0）, hot gas Reynolds number Re∞（150000～250000）and film hole Reynolds numberRe（j5000～13500）were changed to investigate the discharge coefficient Cdof film cooling. It wasfound Cdincreases with blowing rate when the Re∞and Rejare constant, and this trend decreasesin lager M case. The experimental results show that Rejaffects Cdfaintly, while blowing rate M isthe most sensitive parameter in experimental cases.