Shock-Wave Mechanism of Detonation Initiation in Premixed Hydrogen–Argon–Oxygen Flow Around a High-Velocity Projectile

A computational method has been developed to model the shock-wave mechanism of detonation initiation by the interaction of a high-velocity projectile (HVP) with a combustible hydrogen–oxygen mixture diluted by with 50% argon under normal conditions. The HVP velocities at Mach numbers $${\text{M}} = 3{-} 4$$ are considered, which are lower than the Chapman–Jouguet detonation velocity in this mixture at normal pressure and temperature. It is shown that the detonation wave is initiated at a HVP velocity exceeding $${\text{M}} = 3.9$$ . In this case, a shock-wave mechanism of initiation occurs in which a detonation wave is formed at the shock wave separated from the combustion wave by the induction zone. In the simulation, a new regime of reacting gas flow around the HVP was identified. In the range of HVP velocities $${\text{M}} = 3.4{-} 3.85$$ , a quasi-steady regime of shock-induced combustion is established. The flow parameters required for the direct initiation of multifront detonation by the HVP are consistent with analytical estimates of the initiation energy.