INVESTIGATION OF THE EFFECT OF FLARE AND RAMP ANGLE ON THE UPSTREAM INFLUENCE OF LAMINAR AND TRANSITIONAL REATTACHING FLOWS FROM MACH 3 TO 7
ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AFB TN
Pagination or Media Count:
An experimental investigation of laminar- and transitional-flow separation induced by flares and ramps of different angles was conducted at Mach numbers 3, 5, and 7 over a broad Reynolds number range. Surface pressure distributions, schlieren and shadowgraph pictures, and the oil film technique were used to determine the effect of transition during flow reattachment on the scale of laminar separation. It is concluded that because transition was always triggered prematurely by the reattachment pressure gradient, small flow deflections theta or 10 deg are required when investigating laminar reattaching flows at similar test conditions. The scale of separation increased with Reynolds number increase, and the pressure distribution upstream of the flare was characterized by the absence of any lengthy plateau whenever the flow was laminar through the reattachment zone. Nose blunting reduced the extent of such separations.
- Fluid Mechanics