论文信息 - Small-Scale Propellers Operating in the Vortex Ring State

Small-Scale Propellers Operating in the Vortex Ring State

The behavior of small-scale propellers operating in vertical descent and through the vortex ring state (VRS) was measured. In particular, a total of 26 propellers with diameters ranging from 9 to 11 in. (0.229 to 0.279 m) were tested in the University of Illinois at Urbana-Champaign (UIUC) 2.8×4 ft (0.853×1.219 m) low-turbulence wind tunnel at low Reynolds numbers to measure the propeller thrust over a range of advance ratios from −0.8 to 0 (rapid descent to hover). Also, time histories of the measured thrust for different propellers were recorded to characterize the unsteady thrust fluctuations for advance ratios through the vortex ring state. The effects of propeller geometry, e.g. pitch and planform effects, on the thrust characteristics of these propellers in the vortex ring state is discussed.

Michael S. Selig | Omkar R. Shetty | M. Selig

[1] E. C. Maskell,et al. A Theory of the Blockage Effects on Bluff Bodies and Stalled Wings in a Closed Wind Tunnel , 1963 .

[2] Leishman,et al. Free-Vortex Wake Predictions of the Vortex Ring State for Single-Rotor and Multi-Rotor Configurations , 2002 .

[3] Michael S. Selig,et al. Propeller Performance Data at Low Reynolds Numbers , 2011 .

[4] K. Tehrani. Propellers in yawed flow at low speeds , 2006 .

[5] J. V. R. Prasad,et al. Simplified Rotor Inflow Model for Descent Flight , 2007 .

[6] Wayne Johnson,et al. Model for Vortex Ring State Influence on Rotorcraft Flight Dynamics , 2013 .

[7] K. W. Mort,et al. WIND-TUNNEL TESTS OF TWO VTOL PROPELLERS IN DESCENT , 1963 .

[8] Mark D. Betzina. Tiltrotor Descent Aerodynamics: A Small-Scale Experimental Investigation of Vortex Ring State , 2001 .

[9] Akira Azuma,et al. Experiments on a model helicopter rotor operating in the vortex ringstate. , 1966 .

[10] Robin B. Gray,et al. Empirical Relation Between Induced Velocity, Thrust, and Rate of Descent of a Helicopter Rotor as Determined by Wind-tunnel Tests on Four Model Rotors , 1951 .