An Engine Demonstration of Active Surge Control

Abstract

Epstein, Ffowcs Williams and Greitzer presented in 1986 arguments that, provided small perturbation stability models were relevant to engine surge and rotating stall, then both could be avoided by active control. The idea was tested and validated on turbocharger compression systems at MIT and Cambridge University. Engine experiments are more difficult, the surge more violent and the signals usually contaminated by noise. This paper describes the early results obtained on a gas turbine engine subjected to the same control strategy. The control system can be switched on when the engine operates in violent surge and smooth operation is restored. This proof that the technique has practical relevance is interesting enough to report in advance of detailed investigations of its scope. This paper reports the experimental details, describes the relevant theoretical model and gives the first positive test results.