Experiments on energy balance and thermal efficiency of pulse detonation turbine engine

A water-cooled single-tube pulse detonation turbine engine (PDTE) system was constructed using a turbocharger designed for automobiles, where the output of the system was the compression work done by the turbocharger. The PDTE system was operated for more than 10 minutes at the frequencies of 10 and 60 Hz using hydrogen as the fuel and air as the oxidizer. In the experiments, the isentropic efficiency of the turbocharger and the energy balance of the system were evaluated by comprehensive diagnostics. The isentropic efficiency of the turbocharger was about 0.6 at the operation frequencies of both 10 and 60 Hz, which was almost the same as the value in the case that only air steadily flowed through the rig. The evaluation of the energy balance showed that about four out of ten of the input energy was lost in the operation. The values of the thermal efficiency evaluated in the PDTE experiments at the frequencies of 10 and 60 Hz were 0.1 and 0.09, respectively. These values were consistent with the theoretical predictions taking account of the evaluated isentropic efficiency of the turbocharger and energy balance of the system.