Heat Transfer in an Airfoil Shaped Strut

Thesis (Ph.D, Mechanical and Materials Engineering) -- Queen's University, 2016-08-31 09:37:50.239

HEAT MANAGEMENT IN THE PUMPING INFRASTRUCTURE AREA OF AN ESTERHAZY MINE

Heat management in mines is a growing issue as mines expand physically in size and depth and as the infrastructure grows that is required to maintain them. Heat management is a concern as it relates to the health and safety of the workers as set by the regulations of governing bodies as well as the heat sensitive equipment that may be found throughout the mine workings. In order to reduce the exposure of working in hot environments there are engineering and management systems that can monitor and control the environmental conditions within the mine. The successful implementation of these methods can manage the downtime caused by heat stress environments, which can increase overall production. This thesis introduces an approach to monitoring and data based heat management. A case study is presented with an in depth approach to data collection. Data was collected for a period of up to and over one year. Continuous monitoring was conducted by equipment that was developed both commercially and within the mine site. The monitoring instrumentation was used to assess the environmental conditions found within the study area. Analysis of the data allowed for an engineering assessment of viable options in order to control and manage the environment heat stress. An option is developed and presented which allows for the greatest impact on the heat stress conditions within the case study area and is economically viable for the mine site.

THE TRANSPORT OF HEAT BY FLOWING GROUNDWATER IN A DISCRETE FRACTURE

In typical theoretical or experimental studies of heat migration in discrete fractures, conduction and thermal dispersion are commonly neglected from the fracture heat transport equation, assuming heat conduction into the matrix is predominant. In this study analytical and numerical models are used to investigate the significance of conduction and thermal dispersion in the plane of the fracture for a point and line sources geometries. The analytical models account for advective, conductive and dispersive heat transport in both the longitudinal and transverse directions in the fracture. The heat transport in the fracture is coupled with a matrix equation in which heat is conducted in the direction perpendicular to the fracture. In the numerical model, the governing heat transport processes are the same as the analytical models; however, the matrix conduction is considered in both longitudinal and transverse directions. Firstly, we demonstrate that longitudinal conduction and dispersion are critical processes that affect heat transport in fractured rock environments, especially for small apertures (eg. 100 μm or less), high flow rate conditions (eg. velocity greater than 50 m/day) and early time (eg. less than 10 days). Secondly, transverse thermal dispersion in the fracture plane is also observed to be an important transport process leading to retardation of the migrating heat front particularly at late time (eg. after 40 days of hot water injection). Solutions which neglect dispersion in the transverse direction underestimate the locations of heat fronts at late time. Finally, this study also suggests that the geometry of the heat sources has significant effects on the heat transport in the system. For example, the effects of dispersion in the fracture are observed to decrease when the width of the heat source expands.