Accession Number : ADA326158

Title :   Forced Response Testing of an Axi-Centrifugal Turboshaft Engine.

Descriptive Note : Technical memo.,

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

Personal Author(s) : Owen, A. K. ; Mattern, Duane L. ; Braun, Donald C. ; Le, Dzu K.

PDF Url : ADA326158

Report Date : OCT 1996

Pagination or Media Count : 18

Abstract : Dynamic data from tests of a T55-L-712 engine are presented. Engine stall/surge data were analyzed using digital signal processing techniques. In addition, forced response testing (system identification studies) was done at various engine speeds. Forced response testing was done using eight jet ejectors approximately equally circumferentially spaced about the compressor front face. This paper presents some preliminary results for the ground idle (approximately 60% of design speed) point. Brief descriptions of the jet injection system, the test matrix, and analysis techniques used are presented. Results of these analyses indicate a substantial transfer of energy across the compressor first stage at some frequencies and that the ejectors are effective in modifying the local flow conditions in front of the first compressor stage.

Descriptors :   *TURBOSHAFT ENGINES, *COMPRESSORS, *FOURIER ANALYSIS, SIGNAL PROCESSING, DIGITAL SYSTEMS, INJECTION, DYNAMICS, AIR FLOW, ENERGY TRANSFER, GAS TURBINES, STALLING, SYSTEMS ANALYSIS, SURGES, STAGING, ENGINE VALVES, EJECTORS.

Subject Categories : Theoretical Mathematics
      Test Facilities, Equipment and Methods
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE