Simulating detonations with tabulated chemistry*

The presence of both shocks and chemical reactions in detonations poses a challenge for simulation efficiency. Detailed chemical kinetic models require one equation per chemical species. To model hydrogen combustion, nine species are needed; for hydrocarbon fuels, there may be hundreds or even thousands of species to consider. The cost of chemistry has been addressed for subsonic reacting flow simulations using the tabulated chemistry method, in which one (or a combination of) species mass fraction tracks the progress of reactions in a system. However, reaction rates and mixture properties also depend on the thermodynamic state. In compressible flows, the temperature and the progress variable are used to describe the enthalpy and specific heat capacity of the mixture, which are used along with the equation of state to compute the pressure. The progress variable, pressure, and enthalpy are then used to obtain the progress variable source term and transport properties. This work extends the methodology that has been implemented for turbulent flames to include one- and two-dimensional detonations. The reduced-order chemical model is validated against simulation data obtained with detailed chemistry.