Thrust performance of rotary-valved four-cylinder pulse detonation rocket engine

We designed a rotary valve for a multi-cylinder pulse detonation rocket engine (PDRE), and constructed a greatly simplified rotary-valved four-cylinder PDRE (inner diameter and length of detonation tube: 37 mm and 1,600 mm, respectively). The partial-fill effect of a propellant in a multi-cylinder PDRE under high-frequency operation was investigated. The suctioned-air fill fraction was estimated using the model of Sato et al., which is a semiempirical formula for the partial-fill effect of a propellant based on two-dimensional numerical analysis [Sato et al., Journal of Propulsion and Power, Vol. 22, No. 1, 2006, pp. 64-69]. A maximum propellant-based specific impulse of 251 s and a time-averaged thrust of 242 N were achieved using C₂H₄-O₂ as the propellant and an operation frequency of 129.6 Hz/tube (fill pressure: 1 atm). The maximum operation frequency was 160.3 Hz/tube (641.2 Hz/all tubes).