Let M be the class of areally mean univalent function, f ∈M and In this paper, we estimate the arithmetical mean of coefficients Dn(λ) and the arithmetical mean of successive coefficients tn(λ) =||Dn+1(λ)|-|Dn(λ)...Let M be the class of areally mean univalent function, f ∈M and In this paper, we estimate the arithmetical mean of coefficients Dn(λ) and the arithmetical mean of successive coefficients tn(λ) =||Dn+1(λ)|-|Dn(λ)||. Our results are sharp. In addition, we also generalize Hayman's theorem on integral mean展开更多
This paper describes the numerical investigations of flow and heat transfer in an unshrouded turbine rotor blade of a heavy duty gas turbine with four tip configurations. By comparing the calculated contours of heat t...This paper describes the numerical investigations of flow and heat transfer in an unshrouded turbine rotor blade of a heavy duty gas turbine with four tip configurations. By comparing the calculated contours of heat transfer coefficients on the flat tip of the HP turbine rotor blade in the GE-E3 aircraft engine with the corresponding ex- perimental data, the K：-o~ turbulence model was chosen for the present numerical simulations. The inlet and outlet boundary conditions for the turbine rotor blade are specified as the real gas turbine, which were obtained from the 3D full stage simulations. The rotor blade and the hub endwall are rotary and the casing is stationary. The influ- ences of tip configurations on the tip leakage flow and blade tip heat transfer were discussed. It＇s showed that the different tip configurations changed the leakage flow patterns and the pressure distributions on the suction surface near the blade tip. Compared with the flat tip, the total pressure loss caused by the leakage flow was decreased for the full squealer tip and pressure side squealer tip, while increased for the suction side squealer tip. The suction side squealer tip results in the lowest averaged heat transfer coefficient on the blade tip compared to the other tip configurations.展开更多
文摘Let M be the class of areally mean univalent function, f ∈M and In this paper, we estimate the arithmetical mean of coefficients Dn(λ) and the arithmetical mean of successive coefficients tn(λ) =||Dn+1(λ)|-|Dn(λ)||. Our results are sharp. In addition, we also generalize Hayman's theorem on integral mean
基金supported by the National 973 Program of China through grant number 2007CB210108
文摘This paper describes the numerical investigations of flow and heat transfer in an unshrouded turbine rotor blade of a heavy duty gas turbine with four tip configurations. By comparing the calculated contours of heat transfer coefficients on the flat tip of the HP turbine rotor blade in the GE-E3 aircraft engine with the corresponding ex- perimental data, the K：-o~ turbulence model was chosen for the present numerical simulations. The inlet and outlet boundary conditions for the turbine rotor blade are specified as the real gas turbine, which were obtained from the 3D full stage simulations. The rotor blade and the hub endwall are rotary and the casing is stationary. The influ- ences of tip configurations on the tip leakage flow and blade tip heat transfer were discussed. It＇s showed that the different tip configurations changed the leakage flow patterns and the pressure distributions on the suction surface near the blade tip. Compared with the flat tip, the total pressure loss caused by the leakage flow was decreased for the full squealer tip and pressure side squealer tip, while increased for the suction side squealer tip. The suction side squealer tip results in the lowest averaged heat transfer coefficient on the blade tip compared to the other tip configurations.
