31th Congress of the International Council of the Aeronautical Sciences

03.1 - Aerodynamics - CFD Methods and Validation


G. Qian¹, J. Si¹, K. Liu¹; ¹COMAC, China

The base aerodynamic data for the load simulation comes from wind tunnel data. the Reynolds number in wind tunnel is largely less than the one of full-scale flight ,because of the wind tunnel condition limitation.rnThe supercritical airfoils are applied in the current aircraft wing design. A significant research effort has been emphasized on its improvement. The superior performance enables its widely application to some civil aircrafts, such as A320, A330, A380, B777, and B787 and so on. Supercritical airfoils are characterized by their flatted upper surface (suction side surface), highly cambered aft section, and greater leading edge radius compared with conventional airfoil shapes. Flows about supercritical airfoil are shown to be particularly sensitive to viscosity. The shock location and strength and the interfere of shock and boundary layer are direct affected by the difference of Reynolds number resulting in the variety of load distribution and aerodynamics coefficient, ultimately the load distribution between wing and empennage vary greatly. rnThe load distribution difference is from the absence of study for Reynolds number effect in the C-141design resulting in the aircraft’s newly design. The reason for this newly design is the great difference between wind tunnel Reynolds number and full-scale flight Reynolds number.rnThe aerodynamics connection between wind tunnel Reynolds number and true flying Reynolds number is studied by CFD avoiding load simulation error from wind tunnel data, and then acquire load distribution and aerodynamics coefficient in full-scale flight.rn

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