Effect of Fuel Distribution on the Onset of Detonation in Gaseous Octane Air Mixture
Abstract
Formation of detonation waves in a tube is a complex phenomenon and depends upon many factors like ignition energy, presence of a deflagration to detonation transition (DDT) enhancement device and spatial distribution of fuel, etc. In present study, gaseous octane-air mixtures have been examined by varying the equivalence ratio linearly along the axial direction of the detonation tube though the overall stoichiometry was maintained in the tube. Three different conditions have been modelled and studied, which includes small, moderate and large, fuel density gradient in axial direction with equivalence ratio ranging from 1 to 2 near the ignition zone. A series of simulation study have been conducted and the analysis of simulation results reveal that the DDT onset is significantly affected by the initial fuel distribution at the ignition zone as well as on fuel density gradient in a detonation tube. It has been observed thata moderate gradient in the fuel density distribution is favorable for onset of detonations. From the study of pressure plots for above mentioned conditions it has been found that the presence of large gradients in fuel density has adverse effect on the stability of detonation wave.
References
Bussing, T. & Pappas, G. an introduction to pulse detonation engines. In Proceedings of 32nd Aerospace Science Meeting and Exhibit, Reno, NV, 10-13 January 1994. doi: https://doi.org/10.2514/6.1994-263
Gagnon, N. E. & attia, M. The effect of axial spacing of constant and variable blockages on the deflagration to detonation transition in a pulse detonation engine. InProceedings of 52nd aIaa/SaE/aSEE Joint Propulsion Conference, Salt lake City, uT, 25-27 July 2016. doi: https://doi.org/10.2514/6.2016-4648
Nakawatase, R.; Miyazawa, H.; aso, S. & Tani, y. an experimental study on shortening of DDT distance for pulse detonation engines. In Proceedings of 57th International Astronautical Congress, Valencia, Spain, 2-6 october 2006, pp. 1-5. doi: https://doi.org/10.2514/6.IAC-06-C4.5.09
Srihari, P.; Prasad, G. S. K.; Charyulu, b.V.N. & Reddy, D. N. Experimental validation of effect of equivalence ratio on detonation characteristics of propane/oxygen mixtures. Int. J. Recent Adv. in Mech. Eng., 2014, 3(3), 33-42.doi: https://doi.org/10.14810/ijmech.2014.3303
Meyer, T.R.; Hoke, J.l. & brown, M.S. Experimental study of deflagration-to-detonation enhancement techniques in a H2/Air pulsed-detonation engine. In Proceedings of 38th aIaa/aSME/SaE/aSE Joint Propulsion Conference & Exhibit, Indianapolis, Indiana, 7-10 July 2002, pp. 1-11. doi: https://doi.org/10.2514/6.2002-3720
Boeck, l. R.; Berger, f. M.; Hasslberger, J. & Sattelmayer, T. Detonation propagation in hydrogen-air mixtures with transverse concentration gradients. Shock Waves, 2015, 26(2), 181-192. doi: https://doi.org/10.1007/s00193-015-0598-8
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