Numerical Simulation of Gas-Solid Coupling in Pressure-Relief Gas Drainage of Short-Distance and Underprotective Steeply Inclined Coal Seam Mining

Table 2

Model parameters.

Model parameter	Parameter values	Unit
Original gas pressure of No.2-1 coal seam,	1.35	MPa
Original gas pressure of No. 1-8 coal seam,	0.35	MPa
Original gas content of No. 2-1 coal seam,	9.50	m^3/t
Original gas content of No. 1-8 coal seam,	3.42	m^3/t
Initial permeability of coal seam,	0.092	mD
Diffusion coefficient of pore system in coal seam,		m^2/s
Gas dynamic viscosity,		PaS
Gas density under standard conditions,	0.714	kg/m^3
Adsorption constant,	30.286	m^3/t
Adsorption constant,	0.375	MPa^-1
Molar volume of gas,	0.0224	m^3/mol
Molar mass of gas,	0.016	kg/mol
Standard atmospheric pressure,	0.10	MPa
Initial porosity of coal,	8.022	%