Fig 1.
Grid division of calculated model.
Fig 2.
Calculated results of model.
Fig 3.
Three-dimensional wall jets sketch.
Fig 4.
Non dimensional velocity distribution in the radial decay region of the central plane.
Fig 5.
Non dimensional longitudinal maximum velocity distribution.
Fig 6.
Airflow field analysis diagram of extracted ventilation under different conditions.
Fig 7.
Flow velocity zoning diagram.
Fig 8.
Harmful gas retention under different conditions.
Fig 9.
CO concentration variation process with different duct positions.
Fig 10.
Ventilation time required with different duct positions.
Fig 11.
CO concentration variation process with different distance between duct outlet and working face.
Fig 12.
Ventilation time required with different distance between duct outlet and working face.
Table 1.
Comparison of simulation results for various operating conditions.
Table 2.
Calculation results of integrated concentration of polluted gases at the duct outlet.
Fig 13.
CO concentration variation process with different duct velocity.
Fig 14.
Ventilation time required with different duct velocity.
Fig 15.
Results of different calculated conditions.
Fig 16.
CO concentration variation at the air duct outlet with different distance between air duct outlet and working face.
Fig 17.
CO concentration variation at the air duct outlet with different air velocity.
Fig 18.
Relationship between Cd and t with different distance between air duct outlet and working face.
Fig 19.
Relationship between Cd and t with different air velocity.
Fig 20.
Relationship between In(C0VI-CdQt)Cd and In(C0Qt).
Table 3.
Engineering parameters and air volume determined for the case tunnels.