Underground mining of coal deposits, especially on deep horizons, is accompanied by frequent manifestations of negative factors. The greatest hazard is represented by shock-wave phenomena that initiate detonation waves, which manifest themselves in the form of explosions. They are related to the accidents with the most serious economic and social consequences.
Traditionally, the theory of shock waves in gases is based on the ideal gas model. However, in the mine workings with a frame lining of rough pipes, the presence of the mentioned roughness creates significant resistance to the movement of the gas-air mixture, which leads to the need in considering its viscous properties.
The article examines the structure, evolution and stability of the shock waves in viscous gas-air mixtures formed in the atmosphere of the mine workings as a result of gas sudden release from the underground reservoir with the supersonic speed. Based on the classical laws of conservation of mass, impulse and energy, the formula is obtained that characterizes the change in the velocity of the gas-air mixture behind the shock wave front. The width of the shock wave front is calculated, the graphs of its dependence on various parameters of the gas-air mixture are plotted. Some regularities were identified concerning the changes in the width of the shock wave front and the velocity of gas-air mixture in the mine workings. It was established that with the increase in the Mach number in the undisturbed flow this velocity nonlinearly decreases (the more significant the smaller is the Poisson adiabat index of gas-air mixture). Analysis of the shock-wave front structure showed that its width with the Mach number of more than 1.8 does not depend on the Poisson adiabatic index.