Accession Number : ADP005518

Title :   A Numerical Study of Unsteady Flow Effects in a Supersonic Compressor Cascade,

Corporate Author : AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH

Personal Author(s) : Richardson,Scott M.

Report Date : MAR 1987

Pagination or Media Count : 11

Abstract : Recent experimental evidence exists which suggests that compressor cascades operating supersonically may pass a higher mass flow with a periodic inflow condition than with the thermodynamically equivalent mass-averaged steady condition. Since most compressor design methods rely on the use of an axi-symmetric analysis, any excursion in mass flow caused by blade row interactions will not be accounted for in the design. In the present study the two-dimensional Navier-Stokes equations are solved using the MacCormick explicit algorithm to obtain the flow in a subsonic rotor cascade for both periodic and steady flow inlet conditions. A new outflow boundary condition is presented to model the unsteady cascade exit flow conditions by using localized heat addition to produce a choke point near the downstream boundary. A computational study of the wake model parameters used in the periodic inlet boundary condition is performed to determine their effect on the cascade mass flow swallowing capacity.

Descriptors :   *AXIAL FLOW COMPRESSORS, *CASCADES(FLUID DYNAMICS), *SUPERSONIC CHARACTERISTICS, MASS FLOW, TWO DIMENSIONAL FLOW, NAVIER STOKES EQUATIONS, COMPRESSOR BLADES, UNSTEADY FLOW, WAKE, DOWNSTREAM FLOW

Subject Categories : Fluid Mechanics
      Hydraulic and Pneumatic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE