Parameters of Viscous Heat-Conducting Gas-Air Flow in Mining Behind the Shock Front

Abstract

With the transition of mining operations to deeper horizons, the safety of miners in coal mines is significantly reduced. This is mainly due to the manifestation of gas-dynamic and the thermische factors, the first of which include sudden emissions of coal and gas, gas venting, shock and detonation waves in the atmosphere of mine workings. The reasons for the thermal factors are the presence of dust-gas-air mixtures prone to chemical oxidation reactions of carbonaceous substances, and the formation of self-heating foci, which lead to changes in the temperature field in the atmosphere of mountain rocks and their surroundings, which significantly increases the probability of occurrence of deflagration and detonation processes. In this paper, the parameters of the shock front in a viscous heat-conducting gas-air flow formed by a sudden release of gas from an underground tank into a mine with a supersonic speed are determined. It is assumed that the movement of the gas-air mixture during the transition of the shock front is stationary, which made it possible to use the fundamental laws of conservation of mass, pulses and energy. The formulas determining the parameters of the gas-air flow are obtained, their graphs are constructed and some regularities of the flow parameters change behind the shock front depending on the initial Mach number and the Poisson adiabatic index are revealed.