Performance characteristics of a model VTOL lift fan in crossflow.

Abstract

This paper presents a summary of principal results obtained from crossflow tests of a model 15-in.-diam lift fan installed in a wing in the NASA Lewis Research Center, 9 X 15 ft V/STOL Propulsion Wind Tunnel. Tests were run with and without exit louvers over a range of tunnel air speeds, fan speeds, and wing angle of attack. Fan thrust in crossflow was influenced by two principal factors: the effects of inflow distortion on blade-row performance; and changes in fan stage operating point brought about by changes in back pressure ratio. In this particular fan, flow separation on the inlet bellmouth did not appear to be a serious problem for crossflow operation.

Experimental investigation of the aerodynamic characteristics of generic fan-in-wing configurations

“…Inlet guide vanes above the fan inlet can reduce the inflow distortion and improve the fan performance (11) . The back pressure at the fan exit was also found to significantly affect the fan performance (12) . Results obtained with different fan-in-wing wind-tunnel models were compared by Hickey (13)(14) .…”