The laminar-to-turbulent transition on high-speed rotating propeller blades is investigated in the present work experimentally. The analysis of limitations for optical skinfriction measurements by the oil-film interferometry, as well as of the results of feasibility experiments in the low-speed wind-tunnel BLSWT of AIRBUS Bremen at propeller rotation rates from 3000 up to 14400 rpm (50-240 Hz) and free-stream flow speeds between 30 and 70 m/s are included. The effects of Reynolds number and of the propeller advance ratio on the transition location and on flow topology are discussed. NomenclatureA variable of the thin-oil-film equation a acceleration a rot shear stress due to the centrifugal-force impact (a rot = ρ oil ω 2 R h/2) c chord length D propeller diameter g acceleration of gravity h film thickness J propeller advance ratio (J = πu ∞ /v rot = u ∞ /(nD)) k thermal conductivity M Mach number n rotation frequency (Hz) n r refraction coefficient P 0 total pressure p static pressure r recovery factor r cr critical onset transition (induced by leading-edge separation) radius r, θ polar coordinates R propeller radius ReReynolds number Re nD propeller Reynolds number (Re nD = (nD 2 )/ν) Re nr locally defined propeller Reynolds number (Re nr = (n4r 2 )/ν) Re nr,cr critical Reynolds number (Re nr,cr = (n4r 2 cr )/ν) t time T absolute temperature, or variable of the thin-oil-film equation T 0 total temperature

No abstract

No abstract

No abstract

No abstract