PROBLEM OF DYNAMIC STALL SIMULATION REVISITED

Simulating dynamic stall characteristics in subscale wind-tunnel tests often presents an insolvable problem. At stall the peak velocity on t he airfoil is several times larger than the freestream velocity, causi ng compressibility effects to be unusually large. Consequently, simula tion requires testing at the full-scale Mach number and Reynolds numbe r, a capability beyond the means of most test facilities. An additiona l problem is presented by wall interference in so-called two-dimension al dynamic stall tests. Subscale test results are examined against thi s background of simulation problems.