Springer Science and Business Media LLC

A mathematical model is proposed to describe ignition and combustion of a hydrocarbon fuel (kerosene vapor in air). Based on an analysis of experimental data on the ignition delay dependence on temperature, approximation formulas are derived for the ignition delay as a function of species concentrations and of the pressure and temperature of the mixture. A method for determining the pre-exponent in the kerosene combustion kinetic equation as a function of the local temperature of the mixture is proposed, which provides a reasonably accurate description of the time of mixture combustion. Based on this kinetics, the structure of the detonation wave in a stoichiometric kerosene-air mixture and in a mixture with a reduced fraction of the oxidizer for the Chapman-Jouguet and overdriven detonation regimes is described.

The enthalpy distribution at the front of one-dimensional flames of homogeneous mixtures of hydrogen, propane, formaldehyde, and methanol with air was numerically investigated. It is shown that the enthalpy distribution is more complex than the classical concepts: the enthalpy can both increase and decrease relative to the initial value. The specific form of the distribution is determined, in particular, by intermediate components formed at the flame front as they are also carriers of chemical energy and transfer it due to diffusion.

Initiation of bubble detonation by a short shock wave generated by exploding a wire located in a chemically active bubbled medium is studied experimentally. Critical energies of detonation initiation are determined for different volume fractions of bubbles. It is demonstrated that this method of initiation transforms the compression wave to a detonation wave at a length of ≈0.3 m. In the case of a wire explosion in a gas-liquid medium, the critical energy of bubble detonation initiation can be reduced by more than two orders of magnitude, as compared with initiation by a gas detonation wave.

The quality of a high‐enthalpy air flow is considered in terms of simulating full‐scale flow parameters in studying supersonic combustion. It is shown that the plasmatron with gas‐vortex stabilization of the arc, which was used in experiments, can provide, in a wide range of pressures and temperatures, a level of specific erosion of electrodes equal to 10-7–10-9 kg/C and a concentration of nitric oxide lower than 0.06 %, which has almost no effect on the flow structure and basic characteristics of ignition and combustion processes.