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Jet-boundary and Plan-form Corrections for Partial-span Models with Reflection Plane, End Plate, and No End Plate in a Closed Circular Wind Tunnel

出版	National Advisory Committee for Aeronautics, 1946
URL	http://books.google.com.hk/books?id=13dkQQAACAAJ&hl=&source=gbs_api

註釋A method is presented for determining the jet-boudary and plan-form corrections necessary for application to test data for a partial-span model with a reflection plane, an end plate, or no end plate in a closed circular wind tunnel. Examples are worked out for a partial-span model with each of the three end conditions in the Langley 19-foot pressure tunnel and the corrections are applied to measured values of lift, drag, pitching-moment, rolling-moment, and yawing-moment coefficients. A comparison of the corrected aerodynamic characteristics for all three end conditions indicates that good agreement is obtained with flaps neutral at values of lift coefficient below the stall and that somewhat less satisfactory agreement is obtained in the region of maximum lift coefficient or with flaps deflected. Except for the corrections to the rolling moment coefficient, the jet-boundary corrections were somewhat smaller for the reflection-plane condition than for either of the other end conditions because the induced upwash angle was the lowest; also the plan-form corrections for this end condition were considerably smaller because the wing lift distribution was the least altered as compared with that for a complete wing. From every consideration, the use of a reflection plane gave the best results for tests of a partial-span model.