Download or read book Approximation of the Spanwise Distribution of Wind-tunnel-boundary Interference on Lift of Wings in Rectangular Perforated-wall Test Sections written by Ray H. Wright and published by . This book was released on 1968 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approximation method has been developed for calculating the spanwise distribution of wind-tunnel-boundary upwash interference on lift of wings in rectangular perforated-wall test sections. This method is applied to square test sections with an assumed effective permeability constant of 0.6. A problem of considerable difficulty in practical application of the method presented is the estimation of an effective permeability constant. Because of the variation of the upwash interference with Mach number and of the influence of boundary layer on the effective permeability factor, the boundary interference in a perforated-wall wind-tunnel test section at high subsonic Mach numbers is likely to be of the nature of that in an open-throat tunnel.