Parametric Investigation of Thrust Augmentation by Ejectors on a Pulsed Detonation Tube

Jack Wilson, Alexandru Sgondea, Daniel Paxson, Bruce Rosenthal
2005 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit   unpublished
A parametric investigation has been made of thrust augmentation of a 1 inch diameter pulsed detonation tube by ejectors. A set of ejectors was used which permitted variation of the ejector length, diameter, and nose radius, according to a statistical design of experiment scheme. The maximum augmentations for each ejector were fitted using a polynomial response surface, from which the optimum ejector diameters, and nose radius, were found. Thrust augmentations above a factor of 2 were measured.
more » ... f 2 were measured. In these tests, the pulsed detonation device was run on approximately stoichiometric air-hydrogen mixtures, at a frequency of 20 Hz. Later measurements at a frequency of 40 Hz gave lower values of thrust augmentation. Measurements of thrust augmentation as a function of ejector entrance to detonation tube exit distance showed two maxima, one with the ejector entrance upstream, and one downstream, of the detonation tube exit. A thrust augmentation of 2.5 was observed using a tapered ejector. This publication is available from the NASA Center for AeroSpace Information, 301-621-0390. REPORT DOCUMENTATION PAGE REPORT DATE SECURITY CLASSIFICATION OF ABSTRACT SECURITY CLASSIFICATION OF THIS PAGE Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.
doi:10.2514/6.2005-4208 fatcat:ji5dahxqjbdvznr3y6dulya7wy