Accession Number : ADA326234

Title :   Dynamic Modeling of Starting Aerodynamics and Stage Matching in an Axi-Centrifugal Compressor.

Descriptive Note : Technical memo.,

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

Personal Author(s) : Wilkes, Kevin ; O'Brien, Walter F. ; Owen, A. K.

PDF Url : ADA326234

Report Date : OCT 1996

Pagination or Media Count : 9

Abstract : A Dynamic Turbine Engine Compressor Code (DYNTECC) has been modified to model speed transients from 0-100% of compressor design speed. The impetus for this enhancement was to investigate stage matching and stalling behavior during a start sequence as compared to rotating stall events above ground idle. The model can simulate speed and throttle excursions simultaneously as well as time varying bleed flow schedules. Results of a start simulation are presented and compared to experimental data obtained from an axi-centrifugal turboshaft engine and companion compressor rig. Stage by stage comparisons reveal the front stages to be operating in or near rotating stall through most of the start sequence. The model matches the starting operating line quite well in the forward stages with deviations appearing in the rearward stages near the start bleed. Overall, the performance of the model is very promising and adds significantly to the dynamic simulation capabilities of DYNTECC.

Descriptors :   *TURBOSHAFT ENGINES, *CENTRIFUGAL COMPRESSORS, *AXIAL FLOW COMPRESSORS, OPERATIONAL EFFECTIVENESS, COMBUSTORS, GAS TURBINES, MASS FLOW, STALLING, STARTING, STATIC PRESSURE, TRANSONIC FLOW.

Subject Categories : Jet and Gas Turbine Engines
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE