The Influence of the Initial Temperature on DDT Characteristics in a Valveless PDC

Abstract

The detonation velocity and the detonation cell width are determined experimentally as a function of the initial mixing temperature in a valveless pulse detonation combustor (PDC). The initial temperature was varied from 290 K up to 650 K. To shorten the run-up distance to the deflagration-to-detonation transition (DDT), the detonation tube was equipped with six orifice plates which support the flame acceleration. Ionization probes are used to record the combustion event at several axial positions. Sooted foils inside the downstream section of the detonation tube are used to record the imprint of the detonation front and to determine the detonation cell width. It was found that the propagation speed of the detonation front decreases with increasing mixing temperature, which agrees with the theoretical temperature dependence of the CJ-velocity. The detonation cell width decreases linearly for elevated initial temperatures.

Unsteady Effects on NOx Measurements in Pulse Detonation Combustion

“…The current design of the PDC test rig is derived from the one that was developed and tested previously in Gray (2017), with the latest changes in design described in Völzke et al (2019). The combustion chamber has an inner tube diameter of 30 mm and consists of an injection section (shown in detail in Fig.…”