摘要: Experiments were conducted on a 76 deg. swept cylinder to establish the conditions for the attachment-line transition process with, and without, surface roughness in a low-disturbance ('quiet'), Mach number 1.6 flow. Local flow pa... 展开 Experiments were conducted on a 76 deg. swept cylinder to establish the conditions for the attachment-line transition process with, and without, surface roughness in a low-disturbance ('quiet'), Mach number 1.6 flow. Local flow parameters were estimated from pressure measurements. These were in good agreement with predictions from an Euler code (CFL3D) and a boundary layer code (BL3D). Hot-wires and Schlieren photography were used to determine the state of the boundary layer. It was found that, for a near-adiabatic wall condition and a smooth surface, the attachment-line, boundary-layer remained laminar up to the highest attainable Reynolds number (R-bar of 790). Transition under the influence of trip wires was found to depend on wind-tunnel disturbance levels and the onset conditions have been established. Results suggest that current design practice, which is based upon data from conventional ('noisy') tunnels, may be highly conservative. 收起