Experiment on combustion characteristics of U⁃bend pulse detonation combustor under high temperature inlet stream

In order to obtain the combustion characteristics of gas⁃liquid two⁃phase multi⁃cycle U⁃bend pulse detonation combustor (U⁃PDC) under high temperature inlet stream, experimental research was carried out by using gasoline and air as fuel and oxidant.The results indicated that the U⁃PDC can achieve stable operation at the working frequency of 15-38 Hz when the inlet temperature was 373 K, and the deflagration to detonation transition (DDT) distance was shortened when the working frequency increased.When the working frequency was 15-25 Hz, the detonation initiation failed at room temperature.The results showed that high temperature inflow can promote the DDT process.At room temperature and working frequency of 15-25 Hz, due to the uneven distribution of combustible gas in the U⁃bend detonation tube, the time when the flame was detected outside of the U⁃bend detonation tube was later than the exit of the U⁃bend detonation tube.When the inflow temperature increased to 373 K, the phenomenon was obviously improved.In addition, the ignition time of U‑PDC was within 3-10 ms, which was greatly affected by ignition delay time.When the working frequency of U⁃PDC was the same and the inlet stream temperature raised from room temperature to 373 K, the wave velocity increased, and the ignition time decreased. © 2022, Editorial Department of Journal of Aerospace Power. All right reserved.