Accession Number : AD0714938

Title :   Observations of Tunnel Flow Separation Induced by an Impinging Jet,

Corporate Author : NATIONAL RESEARCH COUNCIL OF CANADA OTTAWA (ONTARIO)

Personal Author(s) : Tyler,R. A. ; Williamson,R. G.

Report Date : APR 1970

Pagination or Media Count : 22

Abstract : Single jets were directed towards, and perpendicular to, the boundary of the 10-ft x 20-ft test section of the NRC V/STOL Propulsion Tunnel. The position of tunnel flow separation, arising from jet impingement and forward penetration, was determined from wool tuft observations for various conditions of jet geometry, jet velocity, and tunnel speed, relevant to V/STOL models involving discrete jets. The results indicated the separation position, relative to the jet nozzle, to be a simple function of the product of effective mainstream/jet velocity ratio and nozzle height/diameter ratio. A value of this product greater than 1.5 was found to be necessary to ensure tunnel flow separation downstream of the jet nozzle. An approximate extension to inclined jets, based on limited test data, is included. (Author)

Descriptors :   (*FLOW SEPARATION, *JETS), (*SHORT TAKEOFF AIRCRAFT, FLOW SEPARATION), WIND TUNNEL MODELS, MODEL TESTS, NOZZLE GAS FLOW, CANADA

Subject Categories : Aerodynamics
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE