DETERMINATION OF GAS BLOWING EMISSION PARAMETERS FROM COAL MASSIF INTO MINE OPENINGS

A brief analysis of blowing emissions from the underground coal massifs into the mine openings has been performed and it is indicated that the shape and configuration of the reservoirs during gas emission analysis are not taken into account. It is noted that at certain conditions the reservoirs shape and configuration can significantly change the picture of gas emission into mine openings. In this article, an attempt is made to discuss the problem of gasflow inside an underground reservoir, taking into account its shape and configuration.A reservoir consisting of a storage chamber, a tapering and expanding cavities is considered. In discussing this problem, the gas is assumed to be ideal, and its flow is considered within the framework of the classical assumptions of gas dynamics. The procedure for transforming the system of gas dynamics equations consisting of the motion equations in the Eulerian form and the continuity equation to a second-order partial differential equation with respect to the velocity potential is shown. In the case when the equation belongs to a hyperbolic type, its transformation to a system of first-order partial differential equations is performed, for which the Cauchy problem is formulated with respect to the unknown components of the gas velocity and the Mach angle. The solution of the Cauchy problem is constructed numerically. The required gas velocities and local velocity of sound are determined, which made it possible to find the Mach numbers and to reveal some regularities of their distribution along the expanding cavity of the reservoir. On the basis of the constructed solution of the Cauchy problem, the pressure, density and temperature of the gas in the expanding cavity are determined and the regularities of their variation at the outlet from the underground reservoir are noted.