Analysis of a sudden release of a gas-coal mixture from a conical cavity formed during the gas outburst

S.V. Cherdantsev , P.A. Shlapakov, K.S. Lebedev
Scientific Centre VOSTNII on industrial and ecological safety in mountain industry JC (JC NC VOSTNII), Kemerovo, Russian Federation
Russian Mining Industry №6 / 2023 р. 109-115

Abstract: Indispensable attributes in underground coal mining are methane and coal dust of various particle sizes. When they are mixed, coal-gas mixtures are formed, predisposed to various hazardous and extremely hazardous gas-dynamic phenomena, primarily to sudden emissions, accompanied by formation of cavities in the coal massif and intensive release of coal-gas mixtures from these cavities into the mine workings. The article deals with the problem of a one-dimensional stationary flow of a gas-coal mixture in an underground cone-shaped cavity formed during a sudden release. The Euler equation of motion and the continuity equation are used as the basic equations. As a result of their transformation, an ordinary differential equation of the first order is obtained, for which the Cauchy problem is formulated. The solution to the Cauchy problem is a transcendental equation with respect to the desired Mach numbers. The roots of the transcendental equation are calculated using the MathCAD mathematical software suite. Upon finding the Mach numbers, the remaining parameters of the mixture are determined, i.e. the pressure, density and temperature of the gas-coal mixture at any point in the conical region, including their critical values. Graphs are constructed that were used as the basis to establish some regularities of the one-dimensional stationary flow of a gascoal mixture in a conical region. In particular, it was found that with an increase in the Mach number, parameters of the gas-coal mixture decrease non-linearly, and with an increase in the Poisson's adiabatic index, the pressure and temperature decrease, and the density increases.

Keywords: mining, coal seam, sudden emissions, coal gas mixtures, gas dynamics equations, Mach number, critical parameters

For citation: Cherdantsev S.V., Shlapakov P.A., Lebedev K.S. Analysis of a sudden release of a gas-coal mixture from a conical cavity formed during the gas outburst. Russian Mining Industry. 2023;(6):109–115. (In Russ.) https://doi.org/10.30686/1609-9192-2023-6-109-115

Article info

Received: 21.09.2023

Revised: 24.10.2023

Accepted: 03.11.2023

Information about the authors

Sergei V. Cherdantsev – Dr. Sci. (Eng.), Leading Researcher, Scientific Centre VOSTNII on industrial and ecological safety in mountain industry JC (JC NC VOSTNII), Kemerovo, Russian Federation; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Pavel A. Shlapakov – Can. Sci. (Eng.), Laboratory Head, Scientific Centre VOSTNII on industrial and ecological safety in mountain industry JC (JC NC VOSTNII), Kemerovo, Russian Federation; е–mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Kirill S. Lebedev – Senior Researcher, Scientific Centre VOSTNII on industrial and ecological safety in mountain industry JC (JC NC VOSTNII), Kemerovo, Russian Federation; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

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