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dc.contributor.advisorBrophy, Christopher M.
dc.contributor.authorMedina, Carlos A.
dc.date.accessioned2012-03-14T17:35:19Z
dc.date.available2012-03-14T17:35:19Z
dc.date.issued2006-12
dc.identifier.urihttp://hdl.handle.net/10945/2479
dc.description.abstractThe use of detonations to achieve thrust in pulse detonation engines (PDEs) offers significant advantages in efficiency, simplicity, and versatility. An enabling mechanism for practical PDE implementation will likely utilize an efficient deflagration-todetonation transition (DDT) process. This method simplifies detonation generation, but the required length is prohibitive in many applications and limits the frequency of repeatability. Obstacles have historically been employed to minimize the DDT distance, but often result in significant total pressure losses that degrade the delivered efficiency advantages of PDEs. This thesis explored the use of straight and swept ramp obstacles to accelerate DDT while minimizing the overall pressure losses. Computer modeling examined three-dimensional disturbances caused by such obstacles. Experimental tests measured combustion shockwave speed, flame velocity, and flame front interactions with obstacles. Evaluations were completed for several straight ramp obstacle configurations in a modeled two-dimensional flow. The placement of consecutive ramps resulted in flame acceleration accompanied by significant pressure spikes approaching 500 psi. Although detonation was not verified across the instrumented section, experimental data prove that straight ramp obstacles successfully accelerate the DDT process. Computer modeling predicts that swept ramps may be even more effective by introducing streamwise vorticity with a relatively low pressure drop.en_US
dc.description.urihttp://archive.org/details/evaluationofstra109452479
dc.format.extentxviii, 109 p. : col. ill. ;en_US
dc.publisherMonterey California. Naval Postgraduate Schoolen_US
dc.rightsApproved for public release, distribution unlimiteden_US
dc.subject.lcshEngineeringen_US
dc.subject.lcshShock wavesen_US
dc.subject.lcshSpeeden_US
dc.subject.lcshThermodynamicsen_US
dc.titleEvaluation of straight and swept ramp obstacles on enhancing deflagration-to-detonation transition in pulse detonation enginesen_US
dc.typeThesisen_US
dc.contributor.secondreaderSinibaldi, Jose O.
dc.contributor.corporateNaval Postgraduate School (U.S.).
dc.contributor.departmentMechanical and Astronautical Engineering (MAE)
dc.identifier.oclc80749681
etd.thesisdegree.nameM.S.en_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineAstronautical Engineeringen_US
etd.thesisdegree.grantorNaval Postgraduate Schoolen_US
etd.verifiednoen_US


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