Accession Number : ADP005465

Title :   Viscous Analyses for Flow through Subsonic and Supersonic Intakes,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER

Personal Author(s) : Povinelli,Louis A. ; Towne,Charles E.

Report Date : MAR 1987

Pagination or Media Count : 20

Abstract : A parabolized Navier-Stokes code was used to analyze a number of diffusers typical of a modern inlet design. The effect of curvature of the diffuser centerline and transitioning cross sections was evaluated to determine the primary cause of the flow distortion in the duct. Results are presented for S-shaped intakes with circular and transitioning cross sections. Special emphasis is placed on verification of the analysis to accurately predict distorted flow fields resulting from pressure-driven secondary flows. The effect of vortex generators on reducing the distortion of intakes is presented. Comparisons of the experimental and analytical total pressure contours at the exit of the intake exhibit good agreement. In case of supersonic inlets, computations of the inlet flow field reveal that large secondary flow regions may be generated just inside of the intake. These strong flows may lead to separated flow regions and cause pronounced distortions upstream of the compressor.

Descriptors :   *VISCOUS FLOW, *AIR INTAKES, JET ENGINE INLETS, DIFFUSERS, CURVATURE, DISTORTION, SUPERSONIC INLETS, DUCT INLETS, NAVIER STOKES EQUATIONS, PARABOLAS, CROSS SECTIONS, CIRCULAR, TRANSITIONS, VORTEX GENERATORS, FLOW FIELDS, MATHEMATICAL PREDICTION, SECONDARY FLOW, FLOW SEPARATION, COMPUTERIZED SIMULATION

Subject Categories : Fluid Mechanics
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE