Investigating the Impact of Caving on Longwall Mine Ventilation Using Scaled Physical Modeling

  • V. GangradeEmail author
  • S. J. Schatzel
  • S. P. Harteis
  • J. D. Addis


In longwall mining, ventilation is considered one of the more effective means for controlling gases and dust. In order to study longwall ventilation in a controlled environment, researchers built a unique physical model called the Longwall Instrumented Aerodynamic Model (LIAM) in a laboratory at the National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD) campus. LIAM is a 1:30 scale physical model geometrically designed to simulate a single longwall panel with a three-entry headgate and tailgate configuration, along with three back bleeder entries. It consists of a two-part heterogeneous gob that simulates a less compacted unconsolidated zone and more compacted consolidated zone. It has a footprint of 8.94 m (29 ft.) by 4.88 m (16 ft.), with a simulated face length of 220 m (720 ft.) in full scale. LIAM is built with critical details of the face, gob, and mining machinery. It is instrumented with pressure gauges, flow anemometers, temperature probes, a fan, and a data acquisition system. Scaling relationships are derived on the basis of Reynolds and Richardson numbers to preserve the physical and dynamic similitude. This paper discusses the findings from a study conducted in the LIAM to investigate the gob-face interaction, airflow patterns within the gob, and airflow dynamics on the face for varying roof caving characteristics. Results are discussed to show the impact of caving behind the shields on longwall ventilation.


Mine ventilation Longwall mining Roof caving Physical modeling 


Compliance with Ethical Standards


The findings and conclusions in this paper are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention. Mention of any company or product does not constitute endorsement by NIOSH.

Conflict of Interest

The authors declare that they have no conflict of interest.


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Copyright information

© This is a U.S. government work and its text is not subject to copyright protection in the United States; however, its text may be subject to foreign copyright protection  2019

Authors and Affiliations

  1. 1.National Institute for Occupational Safety and Health (NIOSH)PittsburghUSA

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