2
small changes in ventilation layouts in operating stone
mines can be disruptive and time-consuming. Fortunately,
in the present times, we have the advantage of computa-
tional fluid mechanics capabilities, which have revolution-
ized the way we assess and improve ventilation systems
in these environments. These advanced tools enable us to
simulate and model different ventilation configurations,
helping mine operators make informed decisions without
the need for extensive physical adjustments. This not only
saves time and minimizes disruptions but also ensures that
ventilation improvements are more efficient and effective,
ultimately contributing to a safer and more productive
mining operation.
CFD modeling is a powerful tool to analyze and design
mine ventilation systems. CFD modeling has found exten-
sive applications across various domains, encompassing the
analysis of airflow patterns and the dispersion of particulate
matter and gaseous contaminants in diverse mining envi-
ronments, ranging from underground mines to open-pit
operations (Raj et al., 2023 Bhargava et al., 2021 Morla
et al., 2021).
Watkins and Gangrade (2022) utilized a combination
of on-site measurements and CFD simulations to identify
the optimal locations for auxiliary fan placement, aiming to
maximize airflow at intersections within the mine entrance.
Their CFD analysis, as outlined in their study, showcased
that such optimization could yield a substantial increase in
ventilation flow rates and reduce air recirculation. These
enhancements serve to elevate the overall efficiency of venti-
lation systems in large-opening stone mines, thereby reduc-
ing worker exposure to airborne contaminants (Watkins
and Gangrade, 2022).
In a parallel investigation, Gendrue et al. (2023) con-
ducted a field survey within a large-opening stone mine,
using the collected survey data as inputs for numerical
modeling in a CFD model. This study aimed to assess
booster fan airflow distribution. The modeling results
underscored the efficacy of the booster fan as a ventilation
control mechanism for directing airflow within large-open-
ing mines, with its placement proving to be a critical factor
influencing the removal of pollutants by mitigating airflow
recirculation.
This study differs from previous research (Watkins,
2022 and Gendrue,2023) in two main ways. First, it pro-
vides a more thorough CFD model for ventilating stone
mines. Second, it uses CFD methods to gain insights into
the effects of long stone stoppings. This research will pres-
ent a comprehensive three-dimensional CFD model for a
large stone mine using the ANSYS-Fluent software. The
main goal of this study is to examine how two layouts of
in-place stone stoppings affect the efficiency of face ventila-
tion and air recirculation at crosscuts between exhaust and
intake entries.
MINE DESCRIPTION AND FIELD SURVEY
In the winter of 2023, NIOSH conducted the first survey
of air velocity within an underground limestone mine in
Pennsylvania. The primary objectives of this in-mine sur-
vey were to establish boundary conditions, optimize mesh
size, and identify the most suitable turbulence model for
a proposed CFD model. This partner mine employs a
standard split ventilation system, utilizing three primary
entrances to the mine: two for air intake and one for air
return (Figure 1). The intake and return portals are closely
positioned and at same elevations. On average, the entry
dimensions in the mine measured approximately 9.15 m
in height and 15.24 m in width. The mine employed two
1.83-m propeller booster fans (Figure 2d) with each fan
capable of delivering a flow rate of 65.18 m3/s. The fans
are operated under a fixed static pressure of 249 Pa. The
intake fan was situated in the third open crosscut between
the first portal and the second portal entry, inby from the
mine entrance (Figure 1). It functioned to introduce exter-
nal air into the mine and direct it towards the entryways on
the right or southwest side of the portals. The exhaust fan
was located at the last open crosscut going outby to direct
air out through the third cross-cut.
At the time of the ventilation survey, the mine had not
yet commenced production activities, and thus, there was
no haul truck traffic within the mine. The only operations
Figure 1. Mine layout showing ventilation control and
stations of first ventilation survey (S1–S33)
small changes in ventilation layouts in operating stone
mines can be disruptive and time-consuming. Fortunately,
in the present times, we have the advantage of computa-
tional fluid mechanics capabilities, which have revolution-
ized the way we assess and improve ventilation systems
in these environments. These advanced tools enable us to
simulate and model different ventilation configurations,
helping mine operators make informed decisions without
the need for extensive physical adjustments. This not only
saves time and minimizes disruptions but also ensures that
ventilation improvements are more efficient and effective,
ultimately contributing to a safer and more productive
mining operation.
CFD modeling is a powerful tool to analyze and design
mine ventilation systems. CFD modeling has found exten-
sive applications across various domains, encompassing the
analysis of airflow patterns and the dispersion of particulate
matter and gaseous contaminants in diverse mining envi-
ronments, ranging from underground mines to open-pit
operations (Raj et al., 2023 Bhargava et al., 2021 Morla
et al., 2021).
Watkins and Gangrade (2022) utilized a combination
of on-site measurements and CFD simulations to identify
the optimal locations for auxiliary fan placement, aiming to
maximize airflow at intersections within the mine entrance.
Their CFD analysis, as outlined in their study, showcased
that such optimization could yield a substantial increase in
ventilation flow rates and reduce air recirculation. These
enhancements serve to elevate the overall efficiency of venti-
lation systems in large-opening stone mines, thereby reduc-
ing worker exposure to airborne contaminants (Watkins
and Gangrade, 2022).
In a parallel investigation, Gendrue et al. (2023) con-
ducted a field survey within a large-opening stone mine,
using the collected survey data as inputs for numerical
modeling in a CFD model. This study aimed to assess
booster fan airflow distribution. The modeling results
underscored the efficacy of the booster fan as a ventilation
control mechanism for directing airflow within large-open-
ing mines, with its placement proving to be a critical factor
influencing the removal of pollutants by mitigating airflow
recirculation.
This study differs from previous research (Watkins,
2022 and Gendrue,2023) in two main ways. First, it pro-
vides a more thorough CFD model for ventilating stone
mines. Second, it uses CFD methods to gain insights into
the effects of long stone stoppings. This research will pres-
ent a comprehensive three-dimensional CFD model for a
large stone mine using the ANSYS-Fluent software. The
main goal of this study is to examine how two layouts of
in-place stone stoppings affect the efficiency of face ventila-
tion and air recirculation at crosscuts between exhaust and
intake entries.
MINE DESCRIPTION AND FIELD SURVEY
In the winter of 2023, NIOSH conducted the first survey
of air velocity within an underground limestone mine in
Pennsylvania. The primary objectives of this in-mine sur-
vey were to establish boundary conditions, optimize mesh
size, and identify the most suitable turbulence model for
a proposed CFD model. This partner mine employs a
standard split ventilation system, utilizing three primary
entrances to the mine: two for air intake and one for air
return (Figure 1). The intake and return portals are closely
positioned and at same elevations. On average, the entry
dimensions in the mine measured approximately 9.15 m
in height and 15.24 m in width. The mine employed two
1.83-m propeller booster fans (Figure 2d) with each fan
capable of delivering a flow rate of 65.18 m3/s. The fans
are operated under a fixed static pressure of 249 Pa. The
intake fan was situated in the third open crosscut between
the first portal and the second portal entry, inby from the
mine entrance (Figure 1). It functioned to introduce exter-
nal air into the mine and direct it towards the entryways on
the right or southwest side of the portals. The exhaust fan
was located at the last open crosscut going outby to direct
air out through the third cross-cut.
At the time of the ventilation survey, the mine had not
yet commenced production activities, and thus, there was
no haul truck traffic within the mine. The only operations
Figure 1. Mine layout showing ventilation control and
stations of first ventilation survey (S1–S33)