New Prediction Models for Estimation of Aerodynamic Pressure Loss due to a Train of Mine Cars in an Underground Airway
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New Prediction Models for Estimation of Aerodynamic Pressure Loss due to a Train of Mine Cars in an Underground Airway Srivatsan J. Sridharan 1
&
Bhamidipati S. Sastry 1
Received: 27 February 2020 / Accepted: 8 July 2020 # Society for Mining, Metallurgy & Exploration Inc. 2020
Abstract Pressure losses in mine ventilation systems are estimated using friction factors and shock loss factors. The efficient planning and designing of mine ventilation systems depend on the accuracy of the friction factors as well as the shock loss factors that are taken into consideration. While there is a much more acceptable knowledge of what constitutes friction loss in mine roadways, the shock loss factors are in general readily not available for all possible contexts of flow separation phenomena in mines. One such special case of shock loss in mines is the train of mine cars in the airway. Mine cars are widely used for the transportation of material, and the information on shock loss factor for mine cars is limited. This paper examines the pressure loss occurring due to a train of mine cars in an airway using scale model studies and numerical investigations. Computational fluid dynamic (CFD) studies are conducted using four different turbulence models. The performance of different turbulence models is analyzed by comparing it with the experimental results. The study suggests that the boundary layer resolution method is significant in the simulation of shock loss. From the study, it is found that the shock loss factors from presently available model overestimate the pressure loss by 7 to 15 times. A better prediction model for the shock loss factor of a train of mine cars in the airway is proposed using the experimental results. Keywords Shock loss factor . Mine ventilation . Computational fluid dynamics (CFD) . Scale model . Mine car . Turbulence model
1 Introduction Mine ventilation is an essential part of underground mining practice addressing the issues of worker safety and environmental concerns of toxic gases, dust, fire, and explosions. The provision of fresh air from surface is a continuous operation contributing to a significant part of mine power demand. Prudent ventilation planning is required for not only safety but also economical mining operation. For such planning, the determination of energy losses in the ventilation system with decent accuracy is necessary. In mines, the energy losses can be broadly classified into frictional losses and shock losses. Frictional loss is characteristically due to fluid wall
* Srivatsan J. Sridharan [email protected] Bhamidipati S. Sastry [email protected] 1
Department of Mining Engineering, Indian Institute of Technology Kharagpur, Kharagpur, WB 721302, India
interaction and attributed to wall shear (boundary layer) in turbulent flow conditions. Shock loss, on the other hand, is primarily due to flow geometries and configurations leading to flow separation and consequent wake formation. When there is a sudden change in momentum of the fluid, an adverse pressure g
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