Selection of model for the numerical study of the convective jet problem

The heat released by local exhaust ventilation is one of the most common hazards emitted during various industrial processes in industrial buildings. This work solves problems in order to find the numerical solution model that most adequately describes the development of a free convective jet above a flat heat source and a convective jet near the side hood located above the heat source. Various turbulence models and options of wall functions are considered for application in the study of a free convective jet. The data showed that the closest to theoretical results are those obtained when using the standard k-e model together with standard wall functions.

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OPTIMIZING THE CHOICE OF VENTILATING AIR CLEANING EQUIPMENT IN SYSTEMS OF LOCAL EXHAUST VENTILATION

URBAN CONSTRUCTION AND ARCHITECTURE ◽

10.17673/vestnik.2017.03.4 ◽

2017 ◽

Vol 7 (3) ◽

pp. 19-23

Author(s):

Svetlana M. PURING ◽

Denis N. VATUZOV ◽

Gennady I. TITOV

Keyword(s):

Indoor Air ◽

Desirability Function ◽

Ventilation System ◽

Aerodynamic Resistance ◽

Multicriteria Analysis ◽

Local Exhaust Ventilation ◽

Air Cleaning ◽

Exhaust Ventilation ◽

Industrial Buildings ◽

Cleaning Equipment

Functioning of industrial buildings is impossible without correctly organized ventilation system. Its work both regulates heat moist mode and the required indoor air purity that is cleaned with the help of air cleaning equipment. To make decision to construct the required air cleaning equipment at the enterprise it is worthwhile to give additional parameters and to solve a problem of multicriteria optimization to get the best results. The choice of the best variant is supposed to be carried out using Harrington’s desirability function. The conducted multicriteria analysis allowed to reveal optimum characteristics of air cleaning equipment, based on the required purifi cation air degree, the geometrical sizes of the equipment and aerodynamic resistance while introducing any particular device.

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Experimental and numerical study of turbulent mixed convection in a cavity with an internal heat source

Journal of Building Physics ◽

10.1177/1744259117735451 ◽

2017 ◽

Vol 42 (2) ◽

pp. 142-172

Author(s):

A Piña-Ortiz ◽

JF Hinojosa ◽

JMA Navarro ◽

J Xamán

Keyword(s):

Heat Source ◽

Numerical Study ◽

Vertical Wall ◽

Internal Heat ◽

Turbulence Models ◽

Internal Heat Source ◽

Uniform Heat Flux ◽

Air Conditioning System ◽

Average Percentage ◽

Nusselt Numbers

In this study, experimental and numerical results of heat transfer in a ventilated cavity with an internal heat source are presented. The cavity represents a ventilated room with a person inside in a 1:3 scale. It has a vertical wall receiving a constant and uniform heat flux, while the opposite wall is kept at a constant temperature. The rest of the walls is adiabatic. The cavity has multiple inlets and outlets of air, considering ventilation by ducts of an air-conditioning system. Experimental temperature profiles were obtained at six different depths and heights consisting of 14 thermocouples each. Six turbulence models were evaluated against experimental data. The minimum average percentage differences between numerical and experimental average Nusselt numbers of the hot wall and heat source were 12.9% and 4.1% with the renormalized k–ε turbulence model.

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EVOLUTION OF COORDINATION IN SOCIAL NETWORKS: A NUMERICAL STUDY

International Journal of Modern Physics C ◽

10.1142/s012918311001583x ◽

2010 ◽

Vol 21 (10) ◽

pp. 1277-1296 ◽

Cited By ~ 8

Author(s):

MARCO TOMASSINI ◽

ENEA PESTELACCI

Keyword(s):

Social Networks ◽

Network Effects ◽

Numerical Study ◽

Coordination Games ◽

Local Network ◽

Positive Role ◽

Social Polarization ◽

Extensive Numerical Simulation ◽

Theoretical Results ◽

Selection Of

Coordination games are important to explain efficient and desirable social behavior. Here we study these games by extensive numerical simulation on networked social structures using an evolutionary approach. We show that local network effects may promote selection of efficient equilibria in both pure and general coordination games and may explain social polarization. These results are put into perspective with respect to known theoretical results. The main insight we obtain is that clustering, and especially community structure in social networks has a positive role in promoting socially efficient outcomes.

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Numerical Study of Wall Shear and Velocities Using a Commercial CFD Code: Some Crucial Aspects to Consider

Hydro Nepal Journal of Water Energy and Environment ◽

10.3126/hn.v21i0.17821 ◽

2017 ◽

Vol 21 ◽

pp. 45

Author(s):

Binaya Baidar ◽

Michel Cervantes

Keyword(s):

Numerical Study ◽

Turbulence Models ◽

Wall Functions ◽

Energy And Environment ◽

Commercial Code ◽

Index Approach ◽

Grid Convergence ◽

Sst Model ◽

Wall Shear ◽

Grid Convergence Index

This paper presents the numerical prediction of wall shear and velocities in steady and superposed pulsatile turbulent flow in a pipe, the phenomena that can be observed in hydropower. The previously conducted experiment is a base for this study and some crucial aspects of CFD while using a commercial code have been emphasized. The widely-accepted grid convergence index approach is adopted to quantify the discretization uncertainty and the results are validated against the experiment. The influence of the wall functions applied in the code is also studied with two turbulence models: standard k-ε and based SST model. The time-averaged results of superposed flow with small amplitude unsteadiness are equivalent to results from the steady flow. The results and the method used in this paper may be useful for the CFD simulations in hydropower applications like penstock and bifurcations designs. HYDRO Nepal JournalJournal of Water Energy and EnvironmentIssue: 21, July, 2017Page: 45-49Upload Date: July 18, 2017

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Numerical Study of Wall Shear and Velocities Using a Commercial CFD Code: Some Crucial Aspects to Consider

Hydro Nepal Journal of Water Energy and Environment ◽

10.3126/hn.v21i0.17835 ◽

2017 ◽

Vol 21 ◽

pp. 45-49

Author(s):

Binaya Baidar

Keyword(s):

Numerical Study ◽

Turbulence Models ◽

Cfd Simulations ◽

Wall Functions ◽

Commercial Code ◽

Index Approach ◽

Grid Convergence ◽

Sst Model ◽

Wall Shear ◽

Grid Convergence Index

This paper presents the numerical prediction of wall shear and velocities in steady and superposed pulsatile turbulent flow in a pipe, the phenomena that can be observed in hydropower. The previously conducted experiment is a base for this study and some crucial aspects of CFD while using a commercial code have been emphasized. The widely-accepted grid convergence index approach is adopted to quantify the discretization uncertainty and the results are validated against the experiment. The influence of the wall functions applied in the code is also studied with two turbulence models: standard k-ε and kω based SST model. The time-averaged results of superposed flow with small amplitude unsteadiness are equivalent to results from the steady flow. The results and the method used in this paper may be useful for the CFD simulations in hydropower applications like penstock and bifurcations designs. HYDRO Nepal JournalJournal of Water Energy and EnvironmentIssue: 21, July, 2017Page: 45-49Upload Date: July 20, 2017

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