Accession Number : AD0767629

Title :   Analysis of Wall Modification in a Transonic Wind Tunnel,

Corporate Author : ADVANCED TECHNOLOGY LABS INC WESTBURY N Y

Personal Author(s) : Baronti,Paolo ; Ferri,Antonio ; Weeks,Thomas

Report Date : FEB 1973

Pagination or Media Count : 53

Abstract : A method for transonic wind tunnel corrections based on the concept of measuring streamline deflection and pressure in the vincinity of the tunnel walls, and of analytically determining the streamline deflection that corresponds to the measured pressure and the pressure that corresponds to the measured streamline for external uniform free stream conditions at the same Mach number of the test was experimentally investigated. The method involves the additional step of determining the required wall porosity variation or proper wind tunnel cross sectional areas variation and then making the requisite wind tunnel adjustments to obtain interference free flow. Two, two-dimensional, 6% thick circular-arc airfoils were tested at several angles of attack and at free stream Mach numbers of 0.91 and 0.95 in the AFFDL Tri-Sonic Gasdynamics Facility at Wright-Patterson AFB. Only the portion of the data related to zero angle of attack is analyzed in this report. The analysis provides a verification of the experiments themselves, gives some indication of the characteristics of the tunnel ventilated walls, indicates the sensitivity required of the measurements and defines the wall modifications which are required for interference-free conditions. (Author)

Descriptors :   (*TRANSONIC WIND TUNNELS, WALLS), INTERFERENCE, CORRECTIONS, PRESSURE, ANGLE OF ATTACK, AIRFOILS

Subject Categories : Test Facilities, Equipment and Methods
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE