ENERGY FEATURES OF THE CLASSICAL MIXTURE MODEL FOR ESTIMATING DETONATION PARAMETERS IN A LIMITED VOLUME

The article presents the features of detonation parameters estimation in a limited volume taking into account the kinetics of the generalized combustionreaction in the context of the parametric problem of unit reactive impulse maximization. The calculation of the characteristic values of the shock frontand the state of the medium are based on the mixture model without taking into account possible morphological heterogeneity in the form of volumeforces characterizing interphase interaction. Reagents and combustion products are considered as individual components (in terms of their thermophysicalproperties) and described by a single field of velocity, pressure, and temperature with tracking of material relationships. In general, this approachto describing the transport of the medium is common for this type of problem, but there is a certain inconvenience in calculating the energy yield of the reaction, which is based on the heat and mass transfer term (diffusion term) of the energy equation for the mixture. This leads to the fact that in the vast majority of cases it is necessary to reconcile the dependencies of the thermophysical properties of the components (isobaric/isochoric heat capacity, enthalpy and entropy). In this case, there is basically no possibility to influence the energy yield of the reaction, which mostly leads to significantly higher predicted temperatures of the environment compared to the adiabatic parameters of detonation. The article suggests a modification that in the first approximation allows explicit consideration of the reaction energy yield and significantly simplifies the requirements for preparing selfconsistentfunctions of the caloric equation of state of each component. To take into account the kinetics of the detonation combustion reaction, a modifieddirect reaction rate function is constructed on the basis of the Arrhenius relation, which multiplicatively takes into account the "turbulization" ofthe flow, which still needs to be discussed. The proposed model relations were implemented in the form of a custom combustion model in ANSYSCFX, and were used for preliminary evaluation of a single detonation pulse in a limited volume.