The Airflow Reversal Law in Ventilation System after Coal and Gas Outburst in Tunneling Roadway

Table 2

Ventilation parameters of inlet and outlet in return airway.

Outburst pressure (MPa)	Inlet			Outlet
	Velocity magnitude (ms^−1)	CH4 (%)	Pressure (Pa)	Velocity magnitude (ms^−1)	CH4 (%)	Pressure (Pa)
0	1.07	0	6	1.62	0	−12
0.1001	−1.38	78.89	7	3.10	77.93	−11
0.1005	−4.65	90.64	13	5.72	90.67	−3
0.101	−7.00	92.63	22	7.91	93.58	7
0.105	−16.72	95.67	99	17.72	97.27	90
0.11	−24.15	96.68	198	25.36	97.82	198
0.15	−55.75	97.99	1025	58.07	98.5	1092
0.2	−80.07	98.29	2104	83.49	98.66	2271
0.5	−170.00	98.67	9450	177.54	98.84	10305
0.74	−226.95	98.75	16829	236.41	98.88	18275
1	−284.44	98.80	26422	297.38	98.99	28914
5	−2142.67	98.97	1496880	2255.34	98.99	1659410