Performance of Pressure-Gain Combustors Without Moving Parts

Abstract

An outline is presented of the main findings of recent work aimed at establishing the performance potential of pulsed, pressure-gain combustors. Recent advances in methods of performance analysis are described briefly and test results are presented showing that a significant increase of stagnation pressure can be generated. The importance of Reynolds number effects is discussed and the results of tests which quantify these are included. It is shown that the testing of small scale pulsed, pressure-gain combustors generally tends to produce pessimistic results. For example, a stagnation pressure gain of 6% has been achieved at a combustor stagnation temperature ratio of 2.5/1, under laboratory conditions using a small prototype. Predictions indicate that pressure gains of up to twice this value should be attainable with a combustor of four times the diameter of the laboratory prototype. The incorporation of pulsed, pressure-gain combustors in gas turbines as substitutes for conventional combustors is also discussed. Predictions based upon test results show that these devices can have very beneficial effects on the overall performances of gas turbines to which they are fitted.