Model Elements and Network Solutions of Heat, Mass and Momentum Transport Processes

Danko, G.

doi:10.1007/978-3-662-52931-7

Cited by 6 publications

(17 citation statements)

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“…The general balance equation for advection, diffusion, dispersion, convection and accumulation of species e in the moving air is described in [5] in a stationary Eulerian volume V, swept with a Lagrangean flow channel of advection volume V a . The notations are shown in Figure 1 with a stagnant volume space as V-V a , filled by eddies, but with no net advection transport.…”

Section: Eulerian Balance Equation With Lagrangean Internal Transportmentioning

confidence: 99%

“…The transport balance equation for species e in the advection volume is [5]: Figure 1. Control volume and surface for advection, convection, diffusion and accumulation (Reprinted from [5] with permission from Springer).…”

Section: Eulerian Balance Equation With Lagrangean Internal Transportmentioning

confidence: 99%

“…Control volume and surface for advection, convection, diffusion and accumulation (Reprinted from [5] with permission from Springer).…”

Section: Eulerian Balance Equation With Lagrangean Internal Transportmentioning

confidence: 99%

“…Fick's second law may serve as the fundamental component of the governing equations [1] [2], but the formulation is based on the Eulerian, fixed control volume approach which requires fine spatial discretization. In the case of advection and diffusion, the Courant number, Cu, must be kept at Cu = 1 for accurate prediction from time-dependent simulation [3] [4] [5]. In case of moving source and independently moving air, the grid selection must be further constrained.…”

mentioning

confidence: 99%

“…A new method for modeling transport processes has been introduced that combines the Eulerian, fixed control volume with a moving, Lagrangean flow channel for a solution scheme for advection-diffusion problems [5]. The method promises a reduced grid sensitivity due to the intrinsic Cu = 1 condition built into the solution.…”

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confidence: 99%

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Time-Dependent Contaminant Transport in Ventilating Air from a Moving Source

Danko¹,

Asante²

2017

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A new method which combines the Eulerian, fixed control volume with a moving, Lagrangean flow channel is described for the solution of the conjugate, advection-diffusion problem for modeling transport processes of contaminant species. The transport model is presented as a conservative mass balance equation in a state-flux, species transport form in the space-time domain. A fully-implicit, general solution scheme is formulated with matrix operators in the space-time domain. The particular solutions for specific initial and boundary conditions and source term are constructed with the help of a single, inverse matrix operator, A −1 , which has to be calculated only once for all possible particular problems. Although A −1 involves a large number constants, all are independent from the initial, boundary, and source term input vectors. The multi-level, state-flux, space-time (SFST) scheme brings a significant computational acceleration since A −1 has to be calculated only once, such as in mine ventilation cases involving long drifts with constant air flow velocities. Such application is shown in an example for analyzing the transport and concentration distributions of diesel particulate matter (DPM) in the ventilation air at the working area with the interactions between ventilation and a moving diesel loading machine. Comparison between simulation and in situ DPM monitoring results suggests that reliable evaluation of average exposure of DPM to mine workers may be accomplished directly from tailpipe DPM emission data, ventilation air velocity, and mine geometry with the use of the SFST model even in a highly dynamic working area, potentially reducing the need for real-time DPM monitoring.

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Section: Eulerian Balance Equation With Lagrangean Internal Transportmentioning

confidence: 99%

Section: Eulerian Balance Equation With Lagrangean Internal Transportmentioning

confidence: 99%

“…Control volume and surface for advection, convection, diffusion and accumulation (Reprinted from [5] with permission from Springer).…”

Section: Eulerian Balance Equation With Lagrangean Internal Transportmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Time-Dependent Contaminant Transport in Ventilating Air from a Moving Source

Danko¹,

Asante²

2017

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Dynamic Models in Atmospheric Monitoring Signal Evaluation for Safety, Health and Cost Benefits

Danko

Asante

Bahrami

et al. 2019

Mining, Metallurgy & Exploration

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It is prudent to interpret atmospheric monitoring signals in real time for checking the safe limits of the air conditions in underground mines. In gassy mines, real-time evaluation increases the safety of operations. In all mines, continuous monitoring and evaluation contributes to maintaining air conditions within healthy and safe limits. Signal interpretation for safety conditions in mines is difficult for many reasons. An increase in hazardous contaminant concentrations can be predicted by signal pattern recognition, root cause analysis of rapid changes toward deterioration, and forward prediction in time using algorithms and numerical models. The paper describes an early warning system for analyzing monitored signal patterns continuously in real time as well as forward predicting the various environmental and working conditions to recognize dangerous trends that may affect safety and health in underground mines. A dynamic, numerical ventilation model with heat and gas contaminant simulation components is used for the analysis of atmospheric data. Methods and test results are discussed with numerical examples for signal propagation prediction. Several mine examples are studied using controlled, synthetic data for malfunction simulations to evaluate time delays between the detection time of suspicious signal trends and the time of dangerous threshold crossing marking an accident scenario. Delay time is found in the order of 20 min in the examples, signifying the useful time period for preventive intervention between EWS warning and the likely breakout of a following accident.

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