Analysis of Dynamic Operating Characteristics of a Pulse Detonation Turbine Engine

Abstract

In order to obtain the dynamic operating characteristics of a pulse detonation turbine engine (PDTE), a transient model is established considering the shaft dynamics and the volumetric effect of the components in the PDTE. The accuracy of the model is verified with the experimental data from a pulse detonation prototype engine. The deviations between the calculated data and the experimental results are no more than 7.61%. The numerical results show that the operating state of the PDTE will change gradually with the increase of the fuel flow rate or the firing frequency. The quasi-steady state calculations show that there are maximum values for the rotor speed, thrust, and specific thrust when the fuel flow rate is increased from 0.0056 kg/s to 0.0129 kg/s at firing frequency of 10 Hz. The rotor speed, thrust, and specific thrust will suddenly decrease due to the over rich of fuel in the PDC with the increasing of the fuel flow rate. The specific fuel consumption has a minimize value during this process. When the firing frequency is increased from 7 Hz to 18 Hz at a fixed fuel flow rate, the performance parameters such as the thrust, specific thrust, and specific fuel consumption have a similar variation trend. The extremum values of the performance parameters are obtained at firing frequency of 12 Hz. For the dynamic operating process of the PDTE, parameters such as the rotor speed or pressure ratio of the compressor are increased in a cyclic oscillation way when the fuel flow rate or the firing frequency is changed.