3
taking place were scaling operations at various working
faces. Both mine fans were operational during the ventila-
tion survey. Initially, the curtain in Entry 94 was open, and
although efforts were made to close it as effectively as pos-
sible, there was still some air leakage (see Figure 2). The sur-
vey within the partner mine involved conducting 60-second
anemometer traverses. A vane anemometer was attached
to the end of a telescoping pole, extending to 4.27 m in
length. Researchers were able to reach heights ranging from
4.88 m to 5.49 m within the mine entry when fully extend-
ing the telescoping pole. Throughout the mine, measure-
ments were taken and recorded at 33 surveyed stations, as
shown in Figure 1. By extending the pole to its maximum
length, the vane anemometer was utilized to traverse the
“accessible” regions of the mine entry, thereby determining
air velocity. To ensure precise velocity measurements, the
traverse measurements were repeated until readings consis-
tently agreed within a 10% margin of error. Taking into
consideration the entry dimensions and the average veloc-
ity measurements obtained, the volumetric airflow rate was
subsequently calculated. Additionally, smoke tubes were
employed in the mine ventilation surveys to visualize the
flow of air including stagnant areas within the underground
mine. These surveys documented various airflow patterns,
including regions where air stagnation was observed.
In the late spring of 2023, a second ventilation survey
was carried out within the partner mine. During this sur-
vey, it was noted that there had been some minor altera-
tions to the mine’s boundaries since the first survey. The
most significant change compared to the initial survey
was the mine was in active production, with haul trucks
observed entering through the intake-1 portal and exiting
through the intake-2 portal. Furthermore, it was observed
that the curtain in Entry 94 was close. Another notewor-
thy change was the adjustment of the intake fan’s orienta-
tion, which had been redirected away from the adjacent rib
toward the inby of Entry 93 to enhance the airflow towards
the advanced faces at entries M-59 and M-61. During
this survey, air velocity and direction measurements were
taken and recorded at 50 survey stations throughout the
mine. The data collected during this second survey served
two primary purposes: first, to validate the CFD model,
and second, to provide input data for CFD models used to
study the impact of in-place stone stoppings on ventilation
efficiency at working faces.
CFD MODEL SETUP
The study employed ANSYS-Fluent (ANSYS Inc., 2023),
which is commonly utilized by numerous researchers
in the field of underground ventilation engineering for
investigating various fluid-flow and heat transfer issues.
To simulate the airflow within the study mine, a three-
dimensional, steady-state, and incompressible solution
for the Navier-Stokes equations was employed. ANSYS-
Fluent solves these equations in their Reynolds-averaged
(a) Plan view of the mine model
(b) Split ventilation curtain (c) Curtain model
(d) 1.83-m propeller booster fan
(e) Exhaust booster fan (f) Intake booster fan
Figure 2. Planview of CFD model mesh with three-
dimensional close-up focus on the curtain and booster fans
taking place were scaling operations at various working
faces. Both mine fans were operational during the ventila-
tion survey. Initially, the curtain in Entry 94 was open, and
although efforts were made to close it as effectively as pos-
sible, there was still some air leakage (see Figure 2). The sur-
vey within the partner mine involved conducting 60-second
anemometer traverses. A vane anemometer was attached
to the end of a telescoping pole, extending to 4.27 m in
length. Researchers were able to reach heights ranging from
4.88 m to 5.49 m within the mine entry when fully extend-
ing the telescoping pole. Throughout the mine, measure-
ments were taken and recorded at 33 surveyed stations, as
shown in Figure 1. By extending the pole to its maximum
length, the vane anemometer was utilized to traverse the
“accessible” regions of the mine entry, thereby determining
air velocity. To ensure precise velocity measurements, the
traverse measurements were repeated until readings consis-
tently agreed within a 10% margin of error. Taking into
consideration the entry dimensions and the average veloc-
ity measurements obtained, the volumetric airflow rate was
subsequently calculated. Additionally, smoke tubes were
employed in the mine ventilation surveys to visualize the
flow of air including stagnant areas within the underground
mine. These surveys documented various airflow patterns,
including regions where air stagnation was observed.
In the late spring of 2023, a second ventilation survey
was carried out within the partner mine. During this sur-
vey, it was noted that there had been some minor altera-
tions to the mine’s boundaries since the first survey. The
most significant change compared to the initial survey
was the mine was in active production, with haul trucks
observed entering through the intake-1 portal and exiting
through the intake-2 portal. Furthermore, it was observed
that the curtain in Entry 94 was close. Another notewor-
thy change was the adjustment of the intake fan’s orienta-
tion, which had been redirected away from the adjacent rib
toward the inby of Entry 93 to enhance the airflow towards
the advanced faces at entries M-59 and M-61. During
this survey, air velocity and direction measurements were
taken and recorded at 50 survey stations throughout the
mine. The data collected during this second survey served
two primary purposes: first, to validate the CFD model,
and second, to provide input data for CFD models used to
study the impact of in-place stone stoppings on ventilation
efficiency at working faces.
CFD MODEL SETUP
The study employed ANSYS-Fluent (ANSYS Inc., 2023),
which is commonly utilized by numerous researchers
in the field of underground ventilation engineering for
investigating various fluid-flow and heat transfer issues.
To simulate the airflow within the study mine, a three-
dimensional, steady-state, and incompressible solution
for the Navier-Stokes equations was employed. ANSYS-
Fluent solves these equations in their Reynolds-averaged
(a) Plan view of the mine model
(b) Split ventilation curtain (c) Curtain model
(d) 1.83-m propeller booster fan
(e) Exhaust booster fan (f) Intake booster fan
Figure 2. Planview of CFD model mesh with three-
dimensional close-up focus on the curtain and booster fans