A simple reactive gasdynamic model for the computation of gas temperature and species concentrations behind reflected shock waves

A simple gasdynamic model, called CHEMSHOCK, has been developed to predict the temporal evolution of combustion gas temperature and species concentrations behind reflected shock waves with significant energy release. CHEMSHOCK provides a convenient simulation method to study various sized combustion mechanisms over a wide range of conditions. The model consists of two successive suboperations that are performed on a control mass during each infinitesimal time step: (1) first the gas mixture is allowed to combust at constant internal energy and volume; (2) then the gas is isentropically expanded (or compressed) at frozen composition to the measured pressure. The CHEMSHOCK model is first validated against results from a one‐dimensional reacting computational fluid dynamics (CFD) code for a representative case of heptane/O₂/Ar mixture using a reduced mechanism. CHEMSHOCK is found to accurately reproduce the results of the CFD calculation with significantly reduced computational time. The CHEMSHOCK simulation results are then compared to experimental results, for gas temperature and water vapor concentration, obtained using a novel laser sensor based on fixed‐wavelength absorption of two H₂O rovibrational transitions near 1.4 μm. Excellent agreement is found between CHEMSHOCK simulations and measurements in a progression of shock wave tests: (1) in H₂O/Ar, with no energy release; (2) in H₂/O₂/Ar, with relatively small energy release; and (3) in heptane/O₂/Ar, with large energy release. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 189–198, 2008