Accession Number : AD0020564


Title :   THE R.A.E. 4 FT. X 3 FT. EXPERIMENTAL LOW TURBULENCE WIND TUNNEL. PART 4. FURTHER TURBULENCE MEASUREMENTS


Descriptive Note : Technical rept.


Corporate Author : ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (UNITED KINGDOM)


Personal Author(s) : Schuh, H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/020564.pdf


Report Date : Jun 1953


Pagination or Media Count : 84


Abstract : Turbulence in the working section were measured with 2 and 3 screens in the bulge. An extended region of high intensity turbulence near the walls of the working section were observed with 9 screens in the bulge. This region disappeared when the screens were reduced from 9 to 2 or 3. The longitudinal component of turbulence was approximately independent of the number of screens. The lateral component did not change when the screens were reduced from 9 to 3 but did increase by a factor of 2.5 to 3 when the screens were reduced from 3 to 2. The intensities of turbulence were about 12% of the mean speed at the end of the second iffuser and dropped to about 4 to 6% before the rapid expansion. The screens appeared to reduce the turbulence in the rapid expansion and in the bulge below the level of disturbances set up by the inhomogeneities of the last screen. These disturbances are the origin of the lateral components of turbulence in the working section. The extended region is connected with the existence of a return flow in the bulge; possible explanations are offered as to how this produces the region of high intensity turbulence in the working section.


Descriptors :   *TURBULENCE , *WIND TUNNELS , VELOCITY , REGIONS , EXPANSION , UNITED KINGDOM , MEAN , HIGH INTENSITY , WALLS , INTENSITY


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


Distribution Statement : APPROVED FOR PUBLIC RELEASE