Haoyang LI, Zijian ZHANG, Chun WANG
DOI Number: XXX-YYY-ZZZ
Conference number: HiSST2024-00208
This paper presents a pioneering shock-detonation reflection theory and solves the transition criteria to provide a valuable reference for future oblique detonation engine (ODE) design. Initially, we investigate the structure of the oblique detonation wave (ODW) when the deflection angle θ is less than θCJ. We note that the numerical results differ from the theoretical solution predicted by weak underdriven (WU) ODW. When θ < θCJ, a Chapman-Jouguet (CJ) ODW followed by a Prandtl-Meyer isentropic expansion (P-M IE) wave is obtained. In light of this finding, we introduce a CJ + P-M IE theory to reconstruct the relationship between pressure p and θ for the segment of WU detonation polar. Together with the segment of overdriven detonation polar, a whole detonation polar is established. Then, we provide a shock-detonation reflection theory combining the traditional shock polar and the new detonation polar. By analyzing the steady regular reflection (RR) and Mach reflection (MR) structures, we found that the key flow field characteristics, such as the angle of the slip line and reflected ODW, corroborate well with the theory. This verifies the accuracy of shock-detonation reflection theory. Subsequently, we solve the detachment criterion and von Neumann (VN) criterion according to the shock-detonation reflection theory. There are two crucial threshold values: critical heat release QC and critical Mach number MC. When Q < QC, the section of the WU ODW is not employed in the reflection theory. When M < MC, the solution of the VN criterion will be absent. Finally, the transition criteria are verified by numerical simulation under two different heat release Q. The numerical detachment and VN angles are coincident with the theoretical ones. The computations can confirm that the shock-detonation reflection theory and transition criteria are correct in our study.