Experimental validation of the transport phenomena in T-shape channel flow

Abstract

This paper presents the results of experimental and numerical investigations of air flow through the crossing of a mining longwall and ventilation gallery. The object investigated consists of airways (headings) arranged in a T-shape. Maintained for technological purposes, the cave is exposed particularly to dangerous accumulations of methane. The existing system of duct connections causes part of the crossing to be insufficiently ventilated. Properly arranged ventilation should assure methane concentrations are maintained at a safe level. The geometrical scale of the physical model was 1:10. It was assumed that the air flow is steady and isothermal. Stereo Particle Image Velocimetry (SPIV) was used to evaluate the velocity vector components. In this study, two models of turbulence were tested: the standard k-ϵ model and a variation of that model, the RNG k-ϵ model. The examined flow is characterised by such flow features as separation, stream impingement on the wall, stress-driven flow and strong streamline curvature. Velocity fields and scalar (concentration or temperature) fields obtained in the cave by experimental measurements and numerical calculations for different Reynolds numbers are presented and discussed in this paper.