Numerical investigation of sweeping jet actuator on oblique detonation

Abstract

Stable detonation initiation and combustion are critical in the operation of oblique detonation wave (ODW) engine, especially when the engine is subjected to disturbances. In this paper, the sweeping jet is implemented on the wedge to provide an active flow control method for ODW and the combustion zone behind the waves. Numerical simulations are conducted on basis of two-dimensional URANS equations with detailed chemistry reactions. The results indicate that applying the sweeping jet method can reliably induce the ODW at a wedge angle of 18°, resulting in a 25% reduction in initiation length compared to scenarios without jet. It is attributed to the energy input derived from periodic directional changes. Furthermore, the characteristics of initiation and combustion are investigated under different jet positions and total pressures. In the case where the jet total pressure is fixed at 300 kPa, it is observed that there is minimal variation in both the initiation length and combustion area with the sweeping jet position. When the jet position is held constant and the total pressure of the jet varies between 200 and 400 kPa, it is evident that the initiation length and combustion area are more stable under the sweeping jet conditions compared to steady jet cases. This enhanced stability is attributed to the exceptional mixing performance. Specifically, the turbulent kinetic energy within the reaction region and at the injector outlet is enhanced when subjected to the sweeping jet. The present work ends by emphasizing the effectiveness of the sweeping jet in facilitating the formation of ODW, which may provide an understanding for exploring solutions for reliable and stable detonation initiation and combustion.

Novelty and significance statement

A novel approach for initiating and controlling the combustion of oblique detonation wave is proposed, utilizing active flow control through sweeping jet technology. The numerical results demonstrate a 25% reduction in initiation length, attributed to the impact of supplementary energy, compared to the scenario without a jet. Furthermore, the innovative methodology enhances the robustness of combustion against the total pressure fluctuations and the varying of jet locations, in comparison to a steady jet.