Loading...

Experimental Study of the Performance of a Multi-Tube Pulse Detonation Engine

Eidi Attar Zade, Masoud | 2010

876 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 40592 (45)
  4. University: Sharif University of Technology
  5. Department: Aerospace Engineering
  6. Advisor(s): Farshchi, Mohammad; Ghorbanian, Kaveh
  7. Abstract:
  8. Performance of a multi tube pulse detonation engine has been investigated experimentally. A pulse detonation engine uses detonation phenomena and simply consists of a large narrow tube which has closed head, and has feeding system and ignition system. In this tube, detonation is produced periodically to generate thrust. In multi-tube mode, several tubes are arranged in parallel which detonate sequentially. Our PDE consists of 2 tubes with 70 cm length and 25 mm inner diameter which have several places performed for high speed pressure sensors installation. The premixed hydrogen-oxygen mixture are controlled by solenoid valve and injected on head-end and ignited by conventional spark plug. The engine has been mounted on a test stand to measure the generated thrust. Spirals have been mounted at the ignition-end of the tube to facilitate DDT. Keeping spiral diameter fixed at 22mm, the spiral length, pitch, and thickness were varied to produce desirable detonation waves. Spiral selection was based on several criteria including transition to detonation at the end of the spiral and hence minimum length of transition region and the percentage of successful tests in each batch. The results indicate that the spiral pitch has the most influence on minimizing the DDT length and obtaining a desirable detonation. Then, detonation has been generated in the second tube by crossover which transfers pressure wave from first tube to the next. By this method, detonation occurred instantaneously in the second head tube but its velocity decreases a little but becomes regular again. The effects of crossover length and installation position on detonation in the first and second tubes are investigated experimentally and it is understood that the shorter crossover length, the better detonation quality in the second tube will be. Also, as the distance between the installation position of crossover and the first tube’s head-end decreases, its detonation quality is reduced. By obtained data from the previous steps, engine is operated in the multi-tube multi-cycle mode at frequencies up to 5 Hz. In this mode, Nitrogen is purged due to preventing pre-ingnition in injected mixture. Therefore, injected Nitrogen causes the detonation quality to reduce.
  9. Keywords:
  10. Shchilkin Spiral ; Cross Over Operator ; Detonation Wave ; Puls Detonation Engine ; Deflagration-to-Detonation Transition ; Multitube Pulse Detonation Engine

 Digital Object List

 Bookmark

No TOC