Numerical Simulation of a Pulse Detonation Engine with Hydrogen Fuels

The present computational study explores some issues concerning the operational performance of pulse detonation engines (PDE) with hydrogen/oxygen propellants. One- and two-dimensional, transient calculations are employedassuming finite rate chemical kinetic for hydrogen/oxygen combustion based on eight chemical species and 16 reactions. The CFD model was applied to compute the physical attributes of various global detonation phenomena, including shock speed, pressure spike behaviors, and Chapman-Jouguet detonation conditions. Methods for ensuring detonation initiation in the computations by means of a specified high-pressure shock initiation region are examined and details of initiation at closed and open ends are contrasted. The open-end initiation results help to verify the computational methodology and to gain additional insight into the behavior of the closed-end solutions. The effects of reducing ambient pressure at the exit of the cylinder for multicycle operations are investigated. Two-dimensional calculations were performed to study potential precombustion effects due to cyclic refueling processes in the engine. Results indicate that elevated chamber wall temperatures (approximately 1500 K) simulating multiple cycle heating produce some reactions near the wall without predetonation during the refueling process. Overall, one- and two-dimensional approximations are in reasonable agreement. Thrust and specific impulse are computed for a variety of conditions to give an indication of potential performance of a PDE.