Temperature Distortion Generator for Turboshaft Engine Testing

The procedures and unique hardware used to conduct an experimental investigation into the response of a small turboshaft engine compression system to various hot gas ingestion patterns are presented. The temperature distortion generator described herein was capable of creating both steady-state and time-variant, or transient, temperature distortion at the engine inlet by using gaseous hydrogen. The transient temperature ramps produced by the distortion generator during the engine tests ranged from less than 111 deg K/sec (200 deg R/sec) to above 611 deg K/sec (1100 deg R/sec) and generated instantaneous temperatures to 422 K (760° R) above ambient. The distortion generator was used to document the maximum inlet temperatures and temperature rise rates that the compression system could tolerate before the onset of stall for various circumferential distortions and the compressor system response during stall.