Influences Of Vane And Blade Interference On Flow In Tip Gap And Film Characteristics Of Outer Ring

The research on the structural components of aeroengine turbine has never stopped for improving the stability of aviation gas turbine engine and economic index.Turbine outer ring,which is an important component to separate the turbine blade from the casing,is the most relative with gap leakage and turbine efficiency.It is the working component of the turbine rotor with thermal load after the turbine blade.The numerical simulation method was used to calculate the flow characteristics,the total pressure loss and the film cooling efficiency in the gap between the outer ring block and the turbine blade.Getting the data of temperature distribution characteristics and convection heat transfer coefficient distribution,and analysis of the blade tip clearance flow.The paper focuses on the variation of film cooling efficiency under different transient flow conditions and different turbine rotating speeds under the transient flow conditions and the effect of periodic condition of turbine blade of the outlet of turbine outer ring on film cooling efficiency.The results show that with the increase of rotating speed,the convective heat transfer coefficient has experienced three stages: uniform distribution,low intensity of the leading edge and trailing edge,low middle of the leading edge and low trailing edge of the leading edge.Turbine rotating speed variation also affects the flow near the outer casing side of the rotor cascade and the distribution of convection heat transfer coefficients in the blade height direction.Under the blowing ratios of 0.5,1 and 1.5,the turbo stator flow lines and gas film efficiency distribution are compared with the static state at ten different relative positions and the direction of the flow field changes significantly.At the blowing ratio of 1.5,the average film cooling efficiency is highest during one blade rotation period.The main reason for the instantaneous filmcooling efficiency is the position of the film hole relative to the turbine blade,and the secondary factor is the influence of the relative position of the vane on the gas film cooling efficiency.