Thermoelectric detector application for measuring the ignition delay time in a shock heated combustible mixture

Abstract

The problem of flight safety of high-speed aircrafts is primarily related to the reliability of engines, which, in turn, depends on the correct understanding of the processes of ignition and combustion of fuel in the combustion chambers of engines during their design. In this work, a new method for registration the ignition of shock heated gaseous fuels using a thermoelectric detector is proposed. The detector well measures the ignition delay time of fuels in the microsecond range, which is characteristic of detonation processes in the combustion chambers of promising aircraft engines operating on detonation combustion. The efficiency of the detector is demonstrated by the ignition of a propane-air mixture behind a reflected shock wave as an example. During the experiments, the thermoelectric detector showed such properties as the ability to register high heat flux values, low inertia, high signal-to-noise ratio, and high temporal resolution. The data obtained are compared with the measurement data of the ignition delay time by optical and piezoelectric methods obtained in this work, as well as in the studies of other authors.