Experiences with Ultra-High-Bypass Simulators From Calibration and Isolated Engine Testing.

Kurzfassung

Investigations were carried out within a DLR/DNW/NLR co-operation on two Ultra-High Bypass Ratio engine simulators. These so-called CRUF (Counter Rotating Ultra-high bypass Fan) simulators were tested in isolation at low speed (July 1994) in the German Dutch Wind Tunnel (DNW) at the so-called Single Engine Support Stand (SESS). The CRUF calibrations, needed for thrust bookkeeping, were carried out in the NLR model Engine Calibration Facility (ECF, November 1994). The average fan pressures of bothe CRUF units agree fairly well for the SESS and ECF tests. Both CRUF units show a rather large nacelle and pylon drag increase with increasing engine thrust. The prevention of ice build-up at core cowling and rake via a hot film at the outer core cowl surface worked properly and is strongly recommended for proper thrust bookkeeping.