A moving-belt ground plane designed to eliminate the ground boundary layer for tests in ground proximity has been installed in a 17-foot (5.18-meter) wind-tunnel test section at the Langley Research Center. The test section has been calibrated with this moving belt installed, and the effects of ground proximity on the characteristics of a swept and an unswept full-span blowing-flap configuration have been investigated.nThe results indicate that the moving belt satisfactorily removes the boundary layer on the ground plane. The lift loss of models at small distances from the ground and high lifts is considerably less with the belt moving at stream velocity (boundary layer removed) than with the belt at zero velocity. For configurations with full-span lift devices, the data indicate that the moving-belt ground plane is not needed for ratios of wing height (in spans) to lift coefficient greater than about 0.050, but is desirable for smaller ratios.
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