Scaling and flow similarity considerations to develop a 1/40th scaled aerodynamic model of a longwall coal mine for methane hazards investigation

The present work discusses the nuances of scaling and flow similarity to develop a 1/40^th scaled version of a longwall coal mine. Details on the geometric, kinematic, and dynamic scaling of the physical model are presented and discussed. This works also discusses using a 30% CO₂ – 70% He gas mixture as a surrogate for methane. It also presents the implications of various Reynolds numbers (ranging from 7,000 to 140,000) and rotation of the shearer drums in the dynamic representation of the airflow and gas mixtures in the physical scaled model.