Influence of propane additives on the detonation characteristics of H₂-air mixtures

¹ Aeronautical Engineering College, Civil Aviation University of China, No. 2898, Jinbei Road, Dongli District, 300300 Tianjin, P.R. China
² Institut PPRIME UPR 3346, Département Fluides, Thermique, Combustion, CNRS, 1 Av. Clément Ader, BP 109, 86961 Futuroscope Cedex, France

^a e-mail: forrest_cgb@163.com
^b e-mail: bauer@lcd.ensma.fr

Received: 27 November 2013
Revised: 4 February 2014
Accepted: 5 February 2014
Published online: 7 March 2014

Abstract

Hydrogen is more and more considered as a potential fuel for propulsion applications. However, due to its low ignition energy and wide flammability limits, H₂-air mixtures raise a concern in terms of safety. This aspect can be partly solved by adding an alkane to these mixtures, which plays the role of an inhibitor. The present paper provides data on such binary fuel-air mixtures where various amounts of propane are added to hydrogen. The behavior of the corresponding mixtures, in terms of detonation characteristics and other fundamental properties, such as the cell size of the detonation front and induction delay, are presented and discussed for a series of equivalence ratios and propane addition. The experimental detonation velocity is in good agreement with calculated theoretical Chapman-Jouguet values. Based on soot tracks records, the cell size λ is measured, whereas the induction length L _i is derived from data using a GRI-Mech kinetic mechanism. These data allow providing a value of the coefficient K = λ/L _i .