Convective flux analysis on the propagation mechanism of oblique detonation waves

TL;DR

This study uses numerical simulations and vector flux analysis to explore the propagation mechanisms of oblique detonation waves, revealing how transverse wave directions depend on activation energy.

Contribution

It introduces a vector flux analysis method to analyze the propagation mechanism of oblique detonation waves in a two-dimensional numerical model.

Findings

Oblique detonation front has three regions: induction, overdriven detonation, and transverse-wave.

Transverse wave propagation direction depends on activation energy.

Only one transverse wave direction exists at a time, either upward or downward.

Abstract

The aim of this study is to investigate the propagation mechanism of oblique detonation waves using the vector flux analysis method through numerical simulations. A two-dimensional numerical study is conducted on stoichiometric hydrogen-air oblique detonation waves based on the conservative Euler equations and a one-step global chemical reaction model. The wedge angle is 25{\deg}, with a freestream static temperature of 851.5 K, velocity of 2473.4 m/s, and pressure of 42.5 kPa. The motion mechanism of transverse waves is analyzed using the vector flux method. The results show that the oblique detonation front consists of three regions: an induction zone, an overdriven detonation zone, and a transverse-wave region. Under different activation energies, only either upward-propagating or downward-propagating transverse waves exist on the oblique detonation front; the two do not occur simultaneously. At low activation energy, downward-propagating transverse waves dominate, whereas at high activation energy, upward-propagating transverse waves appear.