Download or read book Detonation Branching in a PDE with Liquid Hydrocarbon Fuel written by Kristin L. Panzenhagen and published by . This book was released on 2004-03-01 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: A pulse detonation engine (PDE) capitalizes on the large mass flux and pressure rise associated with detonations to create thrust, which is proportional to PDE cycle frequency. This research showed that using a branched detonation as an ignition source, as opposed to standard spark ignition, deposits more energy into the thrust tube head. The increase in energy decreases ignition delay and detonation to deflagration transition (DDT) time. This allows a theoretical 85% cycle frequency increase that is accompanied by an 85% increase in thrust. The increase in energy also reduces the need for a DDT enhancement device, thereby increasing thrust as much as 30%. While detonation branching has been accomplished using gaseous hydrogen, this was the first instance of detonation branching using liquid hydrocarbon fuel.

Download or read book Development of a Gas Fed Pulse Detonation Research Engine written by R. J. Litchford and published by . This book was released on 2001 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Relation Between Spark ignition Engine Knock Detonation Waves and Autoignition as Shown by High speed Photography written by Cearcy D. Miller and published by . This book was released on 1946 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A critical review of literature bearing on the autoignition and detonation-wave theories of spark-ignition engine knock and on the nature of gas vibrations associated with combustion and knock results in the conclusion that neither the autoignition theory nor the detonation-wave theory is an adequate explanation of spark-ignition engine knock. A knock theory is proposed, combining the autoignition and detonation-wave theories, introducing the idea that the detonation wave develops in autoignited or afterburning gases, and ascribing comparatively low-pitched heavy knocks to autoignition but high-pitched pinging knocks to detonation waves with the possibility of combinations of the two types of knock.

Download or read book Detonability of Hydrocarbon Air Mixtures Using Combustion Enhancing Geometries for Pulse Detonation Engines written by Neil G. Sexton and published by . This book was released on 2001-06 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research studied combustion enhancing geometries and shock reflection on generating a hydrocarbon/air detonation wave in a combustion tube. Ethylene was used as a baseline fuel to determine the preferable geometries. Propane was then used in later testing because of its combustion similarities with heavy hydrocarbon fuels such JP5, JP8, and JP10. Three criteria were used to measure the effectiveness of the combustion enhancing geometries: ability to generate a detonation, wave speed, and time for shock formation. The evaluated geometries included flow-restricting orifice plates and a Schelkin spiral. The shock reflection was accomplished by a vertical fence (large orifice) placed in the last fourth of the tube length. The optimum geometry was found to be the orifice plate used in conjunction with the spiral. Detonations occurred when using ethylene in this configuration, but did not develop when using propane. Because propane's overall reaction rate is slower than that of simpler fuels, more large- and small-scale turbulence to further enhance combustion needs to be generated to create a detonation wave in a short distance when using complex hydrocarbons, such as propane.