Rectangular-Wind-Tunnel Blocking Corrections Using the Velocity-Ratio Method.

摘要

In this report calculations of the ratios of the velocity increments at test bodies to those at the tunnel walls caused by the solid blocking of these bodies within the walls of a closed rectangular wind tunnel are presented. The bodies treated include two-dimensional airfoils; small bodies of revolution; straight, untapered, finite-span wings of varying span; and swept, untapered, finite-span wings of varying span. It is shown that, after wake blocking effects have been removed, the present method furnishes semiempirical blocking corrections for most wind-tunnel models and their components. Results are presented for all the cases mentioned. The test-section proportions of the Southern California Cooperative Wind Tunnel at the California Institute of Technology (viz., ratio of height to width equal to 1/square root of 2) are used in calculations.