Self-Ignition of Propane-Air Mixtures in a Supercharged, Motored Reciprocating Engine

An experimental investigation has been made of the relation to operating conditions of the self-ignition behaviour of propane-air mixtures, in a motored reciprocating engine of 4.8 in bore, at 15.75:1 compression ratio. At each of two speeds, intake pressure was varied up to 22 lbf/in2 abs, and the effect of variation of intake temperature and mixture strength upon self-ignition was observed. The results are presented in terms of measured intake conditions and of computed compression-end conditions, and are compared with those of Moore and Roy. It is shown that a single-step Arrhenius reaction is not an adequate model for correlation of the observations.