Accession Number : AD0700065

Title :   EFFECTS OF EXTERNAL WINDS ON A 1/40-SCALE MODEL OF THE OPEN-CIRCUIT CONFIGURATION OF THE PROPOSED AEDC MULTIPURPOSE LOW-SPEED WIND TUNNEL.

Descriptive Note : Final rept. Jul 68-Jun 69,

Corporate Author : ARNOLD ENGINEERING DEVELOPMENT CENTER ARNOLD AIR FORCE STATION TENN

Personal Author(s) : Anderson,C. F. ; Carleton,W. E.

Report Date : JAN 1970

Pagination or Media Count : 49

Abstract : The effects of external winds on the open-circuit operation of a 1/40-scale model of the proposed AEDC Multipurpose Low-Speed Tunnel were investigated with a wind generator and in the NASA Langley Full-Scale Wind Tunnel. Various inlet configurations were tested in order to determine their effectiveness in reducing the effects of external winds on the test section flow quality. The best inlet configuration reduced the variation in the main test section dynamic pressure distribution to less than plus or minus 2 percent for a 20-ft/sec external wind. The inlet screen alone was sufficient to correct the distortion in the main test section dynamic pressure distribution; however, both an inlet screen and an exit screen were required to attenuate wind gust effects. A semicircular exit screen with solid walls and an open roof was found to be adequate for the main test section; however, an improved exit wind screen will be required if the large test section addition is included. Scaled models of the structure that will be in close proximity to the proposed tunnel produced an increase in the turbulence level of the flow entering the inlet; however, no effects of the structures on the test section flow could be detected. (Author)

Descriptors :   (*WIND TUNNELS, *GUSTS), OPERATION, MODELS(SIMULATIONS), SCALE, AERODYNAMIC CONFIGURATIONS, PRESSURE, TURBULENCE, AERODYNAMIC CHARACTERISTICS

Subject Categories : Aerodynamics
      Test Facilities, Equipment and Methods
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE