Structures and Instability of Oblique Detonations

Abstract

AbstractIt is well known that shock waves can be classified into normal waves and oblique waves. Similarly, there are two classes of detonation waves, oblique and normal ones. As an extreme combustion induced by a shock wave, the leading shock of an oblique detonation wave is an oblique shock, different from the normal shock that leads to normal detonations. The geometric difference of two class detonations is derived from the angle between the inflow and wave surface, which successively results in different total pressure losses when they are used in engineering. For high-speed flights, such as hypersonic aircraft, the total pressure loss induced by normal shocks is not acceptable. Oblique detonations have the potential to be used in engines which are also named oblique detonation engines (ODEs). In addition to ODEs, another propulsion class is a ram accelerator (RA) which can accelerate a projectile into very high-speed using ram-induced combustion or oblique detonation. To develop ODEs and RAs that are still not applicable in engineering, fundamental research in oblique detonation waves (ODWs) is critical to provide a scientific foundation. In this chapter, the progress in ODWs and ODEs is introduced, including theoretical analysis, many numerical studies and a few experimental works.