Accession Number : ADP005467

Title :   Improvement of the Parallel Compressor Model by Consideration of Unsteady Blade Aerodynamics,

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V COLOGNE (GERMANY F R)

Personal Author(s) : Lecht,M.

Report Date : MAR 1987

Pagination or Media Count : 13

Abstract : The parallel compressor model was applied to predict compressor performance with circumferential total inlet distortion. In comparison with the experiment, however, this model gives too pessimistic results for the predicted stall line shift considering sector angles of distortion up to 120 degree. Detailed experimental evaluation of a compressor stage leads to unsteady performance effects obviously being responsible for this discrepancy. To improve the original model, the performance characteristic of the compressor was extended to account for a short time overload capability analogous to an airfoil in an unsteady flow. The governing factor of this modification will be the time-to-stall versus the time for a blade channel to pass the distorted sector. The model improvement has been demonstrated for a DFVLR and a NASA single stage transonic compressor subjected to a screen induced total pressure distortion.

Descriptors :   *UNSTEADY FLOW, *COMPRESSOR BLADES, DISTORTION, JET ENGINE INLETS, PRESSURE DISTRIBUTION, MATHEMATICAL MODELS, TRANSONIC FLOW, STALLING, MATHEMATICAL PREDICTION, WEST GERMANY

Subject Categories : Fluid Mechanics
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE