Andrew Breeze-Stringfellow

Evaluation of Experimental Data From a Highly Loaded Transonic Compressor Stage to Determine Loss Sources

An advanced GE compressor design with high reaction and stage loading, demonstrated front stage efficiencies significantly lower than predicted by CFD calculations. The source of the efficiency miss has proven difficult to pinpoint with conventional inter-stage instrumentation. A test was performed in the NASA Glenn W7 facility with the compressor operating as both a single stage and a two stage machine allowing for the acquisition of detailed traverses at each station throughout the compressor.This paper presents the data from this test and the GE interpretation of what the data implies, concentrating particularly on one operating point, the stage one peak efficiency point. Tracking of the calculated fluid entropy between the exit of the rotor and the exit of the stator leads to the conclusion that there is significant entropy increase in the freestream fluid outside the stator wakes and this loss is believed to be attributable to mixing loss in the rotor wakes. The loss due to wake mixing is largest, and may indeed be amplified, where the rotor wakes pile up on the pressure surface of the stator.Copyright

Unducted fans for aircraft propulsion

The application of the gas turbine toward aviation propulsion, leading to the turbojet engines of Fr…