Study of detonation initiation in kerosene–oxidizer mixtures in short tubes

J Kindracki

doi:10.1007/s00193-014-0519-2

Abstract

The paper describes experimental studies of detonation initiation in a kerosene–oxidizer mixture in a short test tube. The aim of the study is to determine the minimum diameter of the tube and the minimum level of energy that enables direct initiation of the detonation. Knowledge about these values will inform the design of a jet engine combustion chamber in which thermal energy will be generated by a rotating detonation process. The test tube and the oxidizer inside the tube were heated using specially designed heaters installed outside of the tube. The heated oxidizer provided thermal conditions similar to the conditions for a compressor with small to medium static pressure. The study was conducted for four different tube diameters and for various energies of initiation. As a result, measurements of pressure waveforms were obtained for various cases of fuel injection, which were then compared against the results of the shock wave generated by the initiator. This study provides a value for the energy (the pressure of the mixture in the initiator), which provided direct initiation of detonation for a kerosene–oxidizer mixture. Different tube diameters led to the initiation of detonation for various oxygen–nitrogen compositions as an oxidizer.

Highlights

In recent years, detonation as a combustion process has attracted greater attention
Roy et al [1] reviewed a number of Pulse Detonation Engine (PDE) engine design solutions, with different systems controlling the operation of the combustion chamber
The present paper describes experiments that were conducted in order to design a detonation chamber with the use of rotating detonation

Summary

Introduction

Detonation as a combustion process has attracted greater attention. This is due to an increasing number of serious attempts to use it as a combustion process in jet and rocket propulsion. Rasheed et al [2] went a step further, describing the successful application of the study on an 8-tube PDE design as the can-annular combustion chamber working with a gas turbine. They used a stoichiometric mixture of ethylene–air at a mass flow rate of 3.628 kg/s, and a turbine speed of 18,500 rpm. Power of 257 kW was achieved, and the tests lasted for at least 5 min

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Conclusion