Operational issues affecting the practical implementation of pulsed detonation engines

Pulsed detonation engines are slated to be the engines of the future promising better efficiencies and high Mach number applications. There are presently many centers of experimental PDE studies around the world. Most of the studies involve single shot and very short duration test runs. This paper looks at some of the issues faced by engineers studying PDEs, including issues that prevent longer duration testing, and offers some solutions that were developed during several years of PDE study. Some of the concerns investigated include the possibility of damage to the combustion chamber, auxiliary components, diagnostic devices, valves, ignition plugs and DDT enhancing devices, such as Shchelkin spirals, due to the innate extreme conditions of high heat and pressures found in PDEs. Viable solutions are offered that may help overcome these difficulties. Commercial solenoid valves and electronic fuel injectors are presented as the means to achieving higher operational frequencies. In addition, their modularity, low costs and their ability for precision digital control are clear advantages over heavier, more complex rotary or mechanical valving systems. Issues concerning data acquisition, such as proper implementing procedures for pressure transducers and choosing the appropriate sampling rates are discussed. A common concern during the data acquisition is the management of large amounts of data. Some simple and cost effective answers are proposed, such as implementing RAID for computing. EMI is a big concern for engineers in PDE studies because the instruments and devices used in the laboratories are sources of noise. Several solutions are pointed out to mitigate the effects of noise on the signals. Noise control should be looked at proactively during the design stage of the experimental set up because failing to do so can mean retroactive and sometimes costly modifications to experimental setup. Finally, some steps to improve safety during PDE studies are presented.