Browsing by Subject "auxiliary ventilation"

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Access status: Open Access ,
Kształt pola prędkości w wyrobiskach przewietrzanych wentylatorami wolnostrumieniowymi - symulacja numeryczna przy użyciu lepkościowych modeli turbulencji
(Wydawnictwa AGH, 2010) Branny, Marian; Filek, Krzysztof; Nowak, Bernard
Room and pillar headings are frequently ventilated with the use of jet fans. The range of penetration of an air stream generated by the jet fan is determined by several parameters; the major determinants being the initial stream parameters and the place of fan's installation. The paper presents a method of calculation 3D velocity fields in room and pillar headings. Results obtained with the use of three turbulence models, it is two equations model k-l i k-u SST and one equation of Spalart-Allmaras. Calculation were compared with measurements [Meyer 1993].
Access status: Open Access ,
Numeryczna symulacja procesu wentylacji w wyrobiskach ślepych
(Wydawnictwa AGH, 2005) Branny, Marian
The study explores the potential of numerical modelling of airflow in blind headings. The main focus is forecasting the ventilation parameters in headings and galleries characteristic of copper mines belonging to the LGOM Corporation. The fundamentals of mathematical modelling of turbulent flows are provided. The model makes use of 3D continuity and Rynolds equations, the equation of turbulent transport of chemical components and the equations of the k-$\epsilon$ model (kinetic energy of turbulence, the rate of kinetic energy dissipation). The discretisation procedure involved the control volume method and the technique UPWIND. The developed numerical codes employ the hybrid schemes and power-law techniques. Nonlinear systems of discrete equations were solved with the use of SIMPLER procedures. 3D velocity fields and gas concentrations calculated for galleries are provided. The chief objective is to eliminate the hazardous conditions caused by the presence of gas pollutants emitted by diesel-powered engines in machines and produced in the course of blasting operations. The results of numerical solutions of steady-state velocity field and the time-space field of concentration of gaseous pollutant emitted by lumped or distributed gas sources are presented. The accuracy of numerical representation is evaluated by comparing the prognosticated values with measurements. The obtained physical fields by way of numerical procedures portray the real fields sufficiently well for practical purposes
Access status: Open Access ,
Prognozowanie temperatury powietrza w przodkach wyrobisk ślepych przewietrzanych wentylacją lutniową - 3D symulacja komputerowa
(Wydawnictwa AGH, 2009) Branny, Marian; Filipek, Wiktor; Karch, Michał
The solution is supported by equations and simulation programs utilizing the CFD approach. The description of wall boundary conditions utilizes the modify wall function. The temperature of side walls was obtained from the solution of a substitute problem. This temperature is a result of the solution of equation of heat conduction with boundary conditions describing the exchange of heat between the rock and the flowing air. The influence of evaporating water on air temperature was taken into consideration. The volumetric source of heat (negative) was defined in energy equation. The source terms were located in group of cells adjacent to the wall. Calculation data are presented in the form of velocity field and air temperature images in the face zone of a working with a force-exhaust overlap system of ventilation.
Access status: Open Access ,
Projektowanie parametrów wentylacji lutniowej w drążonych wyrobiskach podziemnych z wykorzystaniem programu komputerowego AGHWEN-3.0
(Wydawnictwa AGH, 2005) Szlązak, Nikodem; Obracaj, Dariusz; Szlązak, Łukasz
The principles of designing duct ventilation system and calculation of air distribution along underground headings fitted with leaky ductlines using AGHWEN-3.0 computer programme are presented in the paper. The algorithm of the calculation takes into consideration methane emission into a heading and both the air temperature and humidity distribution along a heading. It takes into consideration the cooperation between ventilation system, dust collection system and air cooling system. On the basis of a few examples the possibilities of AGHWEN-3.0 used in designing a ventilation system are presented.