Numerical investigation of multi-tube pulse detonation

The flow-field interaction among detonation tubes sharing a common nozzle in a multitube-pulsed detonation engine is explored. The evaluations are based on a two-dimensional analysis of first-pulse operation and use a viscous, eight-species, finite-rate, transient flow-field model. Configurations involving single, dual, and triple tubes are considered in both short- and long-tube versions. The common nozzle provides a path through which the detonation from one tube causes a pressure spike in adjacent tubes. Previous studies indicate that the strength of this spike can vary by a factor of five depending on the nozzle throat area and intertube geometry. We indicated that the flow-field interaction among three tubes is approximately a factor of three smaller than the interaction between two tubes, and that increased tube length does not have a significant effect. The results serve as an important precursor to understanding appropriate propellant fill procedures and shock wave propagation in multitube simulations.