Research on Influencing Factors of Effective Gas Extraction Radius in Coal Mine Based on Multiple Linear Regression

Table 1

Physical parameters of the model.

Parameter	Numerical value	Parameter units
Density of coal, ρs	1.47 × 10^3	Kg·m^−3
Initial porosity of coal, φ0	5.06	%
Initial gas pressure of coal, P0	1.4	MPa
Temperature, T	293.14	K
Poisson’s ratio of coal, υ	0.37	—
Gas dynamic viscosity, μ	1.21 × 10^5	Pa·s
Maximum adsorption capacity per unit mass of coal, a	28.327	m^3·kg^−1
Adsorption constant, b	0.793	MPa^−1