عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Steady flows over a 60º delta wing with sharp leading edge are computationally studied at different angles of attack and Mach numbers. Flow patterns over the upper surface of a delta wing are classified into six types based on the component of angle of attack normal to the leading edge and component of Mach number normal to the leading edge MN. Flow patterns over the delta wing studied in this research are compared to known patterns of previous studies and their variations with free-stream Mach number and angle of attack are investigated. Visualization results obtained by numerical simulations show that a leading edge vortex is formed on the upper side of the wing with or without the presence of the secondary separation which gradually expands and becomes closer to the wing surface with increasing Mach number. At Mach numbers higher than 1.2, the leading edge becomes supersonic and the expansion wave emanating from the leading edge accelerates the flow. At this condition, shock waves are formed on the wing which interact the vortices. With increasing angle of attack, the vortex gets away from the wing and closer to the shock wave. The effects of free-stream Mach number and angle of attack on the location of vortex breakdown are also studied.
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