Experimental Validation of Effect Of Equivalence Ratio on Detonation Characteristics of Propane/Oxygen Mixtures

Abstract

Experimental studies were carried out for using Propane as fuel for Pulse Detonation Engine application. In the present study Detonation Characteristics of Propane & Oxygen mixture at various equivalence ratios were presented. In these experiments Propane and Oxygen under regulated pressures were injected into a Detonation Tube from the head end using unlike impinging doublet injector. The fuel and oxidizer were allowed to mix and fill the tube. Subsequently, the mixture was ignited using a spark plug positioned close to the head end of the tube. The pressures generated due to the combustion of the mixtures were captured using five high frequency pressure transducers which were spaced 100mm apart on the detonation tube. Apart from these pressures, velocities of the combustion wave were computed using ‘time of flight’ method. These tests were done for different equivalence ratios varying from 0.8 to 1.6 by varying the feeding pressure of Propane. In the present study the performance of the combustion wave at different locations and effect of equivalence ratios on detonation characteristics were presented. In addition effect of presence of obstacles in the flow path i.e., Shchelkin spirals were also studied in reducing the Deflagration to Detonation Transition (DDT) distance.