Direct Numerical Simulation of Detonation-Turbulence Interaction with Detailed Chemistry

In most practical applications such as advanced propulsion systems (e.g., rotating detonation engines), the unburnt flow is turbulent. Evidence points to turbulence as a potential mechanism behind detonation instabilities. Unfortunately, only a handful of studies have explored the interaction of a detonation wave with turbulence, and of these, only a couple have performed Direct Numerical Simulation (DNS) with detailed chemistry. A recently published detonation regime diagram is presented as a guide for the design of DNS. Key to the feasibility of performing DNS of detonation-turbulence interaction is that the cellular structure (observed in laminar detonations) does not need to be resolved in situations where the turbulent integral length scale is smaller than the detonation cell width. This is shown to hold for most practical interaction regimes. In this work, DNS are performed for a stoichiometric hydrogen/oxygen/argon mixture at an unburnt temperature and pressure of 298 K and 20 kPa, respectively. Planes of homogeneous isotropic turbulence are injected at the inlet. Two turbulence cases are considered corresponding to a turbulent Mach number of 0.01 and 0.1. Planar averages of turbulent length scales, the probability density function of induction length, and the reaction zone roughness are computed. Conditional statistics of the turbulent detonation cases are compared to the laminar and 1-D ZND detonations.