Numerical Simulation of High Expansion Foam Into Conduits and Mine Openings

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Virginia Tech


High expansion foam (Hi-Ex) is a firefighting technology that has been widely used for fire suppression in underground locations. Hi-ex foam can be applied remotely through boreholes from the surface reducing firefighter exposure to fires. Despite the experimental studies that have been carried out there are still some uncertainties about foam behavior in underground locations. For this reason, the main objective of this thesis was to estimate Hi-Ex foam flow behavior in different underground configurations using computational fluid dynamics (CFD) simulations. An experimental apparatus was built to study the foam rheology in order to determine the rheological model parameters to simulate foam as a continuous Non-Newtonian fluid. Furthermore, numerical and experimental results of Hi-Ex foam flowing in a pipe were compared with the objective of validating numerical results.

Results of this study show that Hi-Ex foam with an expansion ratio between 1:250 and 1:1280 behaves as a shear thinning fluid represented by the power law model. Numerical simulations results were between 0.06% and 14% of experimental results for Reynolds numbers between 200 and 1700. Finally, numerical simulations of Hi-Ex foam in different mine entry slopes were carried out and compared with qualitative results of prior field work.

This work generates some of the necessary numerical parameters for the simulation of Hi-Ex foam flow in mines. Furthermore, results of this work and the methodology used can allow for improved predictions of foam flow in in underground mine fires, while improving safety for mine workers



high expansion foam, foam modeling, foam rheology, firefighting foam, mine fires