scholarly journals Using CFD to Evaluate Natural Ventilation through a 3D Parametric Modeling Approach

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2197
Author(s):  
Nayara Rodrigues Marques Sakiyama ◽  
Jurgen Frick ◽  
Timea Bejat ◽  
Harald Garrecht
Keyword(s):  
Natural Ventilation ◽  
Parametric Modeling ◽  
Cfd Simulations ◽  
3D Design ◽  
Post Process ◽  
Test House ◽  
Model Set ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up ◽  
Passive Strategy

Predicting building air change rates is a challenge for designers seeking to deal with natural ventilation, a more and more popular passive strategy. Among the methods available for this task, computational fluid dynamics (CFD) appears the most compelling, in ascending use. However, CFD simulations require a range of settings and skills that inhibit its wide application. With the primary goal of providing a pragmatic CFD application to promote wind-driven ventilation assessments at the design phase, this paper presents a study that investigates natural ventilation integrating 3D parametric modeling and CFD. From pre- to post-processing, the workflow addresses all simulation steps: geometry and weather definition, including incident wind directions, a model set up, control, results’ edition, and visualization. Both indoor air velocities and air change rates (ACH) were calculated within the procedure, which used a test house and air measurements as a reference. The study explores alternatives in the 3D design platform’s frame to display and compute ACH and parametrically generate surfaces where air velocities are computed. The paper also discusses the effectiveness of the reference building’s natural ventilation by analyzing the CFD outputs. The proposed approach assists the practical use of CFD by designers, providing detailed information about the numerical model, as well as enabling the means to generate the cases, visualize, and post-process the results.

IMPROVEMENT OF THERMAL COMFORT INSIDE A MOSQUE BUILDING

2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Fawaz Ghaleb Noman ◽  
Nazri Kamsah ◽  
Haslinda Mohamed Kamar
Keyword(s):  
Thermal Comfort ◽  
Natural Ventilation ◽  
Ventilation System ◽  
Side Wall ◽  
The West ◽  
Cfd Simulations ◽  
Interior Space ◽  
Flow Simulations ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

A combined natural ventilation and mechanical fans are commonly used to cool the interior space inside the mosques in Malaysia. This article presents a study on thermal comfort in the Al-Jawahir Mosque, located in Johor Bahru, Malaysia. The objective is to assess the thermal comfort inside the mosque under the present ventilation system by determining the Predicted Mean Vote (PMV) and the Predicted Percentage of Dissatisfied (PPD). These values were then compared to the limits stated in the ASHRAE Standard-55. It was found that the PMV varies from 1.68 to 2.26 while the PPD varies from 61% to 87%. These show that the condition inside the mosque is quite warm. Computational fluid dynamics (CFD) method was used to carry out flow simulations, to identify a suitable strategy to improve the thermal comfort inside the mosque. Results of CFD simulations show that installing four exhaust fans above the windows on the west-side wall of the mosque is the most effective strategy to improve the thermal comfort inside the mosque. Both the PMV and PPD values can potentially be reduced by more than 60%.

A Quantitative Comparison Between Baseline Hemodynamics and End-Stage Aneurysm Formation in ApoE −/− Mice

2011 ◽  
Author(s):  
Bram Trachet ◽  
Marjolijn Renard ◽  
Gianluca De Santis ◽  
Steven Staelens ◽  
Julie De Backer ◽  
...  
Keyword(s):  
Geometric Model ◽  
Cfd Simulations ◽  
Distance Map ◽  
Abdominal Aortic ◽  
Computational Fluid Dynamics Cfd ◽  
Set Up ◽  
End Stage ◽  
The Relationship

The pathogenesis of abdominal aortic aneurysm (AAA) formation still remains debated. Hemodynamics have been suggested to play a (modulating) role, but no follow-up studies have been performed due to (a.o.) a lack of human data before disease initiation. We therefore used an established mouse model of AAA [1] to study whether AAA develops at locations experiencing disturbed flow. We set up a framework to obtain mouse-specific Computational Fluid Dynamics (CFD) simulations of the mouse abdominal aorta, combining: (i) an in vivo assessed geometric model [2] and (ii) in vivo measured boundary conditions. A distance map was generated to link baseline and end-stage aortic morphologies after AAA development, and the relationship between baseline hemodynamics and end-stage dilatation was quantified.

scholarly journals Numerical Simulation of Air Flow in Multiple Beds Intensive Care Unit of Hospital

2019 ◽  
Vol 16 (2) ◽  
pp. 6796-6807
Author(s):  
A. K. Sahu ◽  
T. N. Verma ◽  
S. L. Sinha
Keyword(s):  
Numerical Simulation ◽  
Associate Degree ◽  
Natural Ventilation ◽  
Air Flow ◽  
Air Velocity ◽  
Cfd Simulations ◽  
Contaminant Particle ◽  
Computational Fluid Dynamics Cfd ◽  
The Mean ◽  
Grid Independence

Indoor air quality ventilation diminishes airborne respiratory and other transmission in hospitals. Airflow in associate medical care Unit (ICU) may be provided through natural mean and additionally by the assistance of mechanical ventilation. Natural ventilation might not be enough to satisfy the requirement of ventilation for associate degree ICU. In the present study, numerical simulation of the airflow pattern and contaminant movement using Computational Fluid Dynamics (CFD) has been carried out for multiple bed hospital ICU with different inlet angles to examine path of contaminant transfer in the hospital. The measurement of air velocity is used as an input and standard k-ɛ turbulence model used in simulation work. Grid Independence Test (GIT) of hospital ICU has been carried out using high-quality tetrahedral unstructured mesh. In order to predict CFD simulations accurately, flow pattern has been validated using model of ICU with four bed and patient occupied with light source. Results shows that increasing rate of air flow change decreases the mean age of air. Importance of outlet position is high for transfer of contaminant particle from ICU.  

CFD Simulations of Natural Ventilation Effect: A Case Study of New Administrative Building of the Guanyin Township

2013 ◽  
Vol 368-370 ◽  
pp. 611-614
Author(s):  
An Shik Yang ◽  
Jen Hao Wu ◽  
Yu Hsuan Juan ◽  
Ying Ming Su
Keyword(s):  
Fluid Dynamics ◽  
Decision Making ◽  
Computational Fluid Dynamics ◽  
Natural Ventilation ◽  
Cfd Simulations ◽  
Wind Environment ◽  
Computational Fluid Dynamics Cfd ◽  
Ventilation Effectiveness

The present study developed a computational fluid dynamics (CFD)-based performance simulator for assessing natural ventilation effectiveness to the central patio and corridors of the new administrative building of the Guanyin Township, Taiwan. The data can share with other potential users for achieving better understanding of the indoor microclimate and the interaction of buildings with urban wind environment for improvement of their design and functioning aspects during the decision-making procedure.

The Best Practice Guidelines for CFD: A European Initiative on Quality and Trust (Keynote)

2002 ◽  
Author(s):  
Torsten Wintergerste ◽  
Michael Casey ◽  
Anthony G. Hutton
Keyword(s):  
Practice Guidelines ◽  
Best Practice ◽  
Cfd Simulations ◽  
Best Practice Guidelines ◽  
European Code ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Turbulence ◽  
Set Up ◽  
Recent Initiative

In the industrial application of Computational Fluid Dynamics (CFD), the quality of simulations and the level of reliability of the results have emerged as major issues of concern. This paper describes a recent initiative of ERCOFTAC (European Research Community on Flow Turbulence and Combustion), involving European code developers, code vendors, academics and industrial users, to set up a practical set of standard guidelines to improve the quality of CFD simulations and to help in the assessment of the trustworthiness of the CFD results. The initiative led to the publication of the first edition of the ERCOFTAC Best Practice Guidelines (BPG) in January 2000. The BPG provide generic advice on how to perform quality CFD calculations. Some examples of typical guidelines from the BPG are provided in this paper.

scholarly journals Comparison of CFD and Multizone Modeling from Contaminant Migration from a Household Gas Furnace

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 79
Author(s):  
Nina Szczepanik-Scislo ◽  
Lukasz Scislo
Keyword(s):  
Natural Ventilation ◽  
Central And Eastern Europe ◽  
Hot Water ◽  
Optimal Placement ◽  
Energy Sources ◽  
Contaminant Migration ◽  
Cfd Simulations ◽  
Domestic Hot Water ◽  
Multizone Modeling ◽  
Computational Fluid Dynamics Cfd

In Central and Eastern Europe, a growing popularity of gas heaters as the main source of heat and domestic hot water can be observed. This is the result of new laws and strategies for funding that have been put in place to encourage households to stop using coal and replace it with cleaner energy sources. However, there is a growing concern that gas furnaces are prone to malfunction and can be a threat to occupants through CO (carbon monoxide) generation. To see how a faulty gas furnace with a clogged exhaust may affect a household, a series of multizone and computational fluid dynamics (CFD) simulations were carried out using the CONTAM software and CFD0 editor created by the National Institute of Standards and Technology (NIST). The simulations presented different placements of the furnace and ventilation outlet in an attached garage. The results showed how the placement influenced contaminant migration and occupant exposure to CO. It changed the amount of CO that infiltrated to the attached house and influenced occupant exposure. The results may be used by future users to minimize the risk of CO poisoning by using the proper natural ventilation methods together with optimal placement of the header in the household.

Environmental model studies for the Istanbul master plan. Part I: hydrodynamical design basis and marine disposal of wastewater

1995 ◽  
Vol 32 (2) ◽  
pp. 141-148 ◽  
Author(s):  
I. S. Hansen ◽  
H. J. Vested ◽  
M. A. Latif
Keyword(s):  
Black Sea ◽  
Layer Structure ◽  
The Black Sea ◽  
Marmara Sea ◽  
Junction Area ◽  
3 Dimensional ◽  
Model Studies ◽  
Model Set ◽  
Characteristic Features ◽  
Set Up

A modelling study of the hydrodynamics and spreading of wastewater from existing and future outfalls in the Bosphorus region has been conducted applying a 3-Dimensional model. The modelling is based on SYSTEM 3, which is a general modelling system for baroclinic flow simulating unsteady currents, waterlevels, salinity and temperature within the model area. The model set-up covers the Black Sea-Bosphorus-Marmara Sea junction area. The set-up is calibrated by data from a dedicated field program and previous field experience. The model is designed to describe the characteristic features of the flow in the junction area such as the effects of variations in waterlevel differences between the Sea of Marmara and the Black Sea on the important two-layer structure in the strait and the flow fields generated by the upper layer jet in the Bosphorus-Marmara junction. This model has been applied for evaluation of disposal of wastewater and for the subsequent water quality studies. The general use of a baroclinic 3-D hydrodynamic model to simulate disposal of wastewater is discussed. Examples of the application of the model of the junction area to evaluate the different strategies for disposal of wastewater are presented.

Modelling of impregnation of γ-alumina with cobalt and molybdenum salts. CoCl2-(NH4)2MoO4-γ-Al2O3 (aluminate type) system

1987 ◽  
Vol 52 (3) ◽  
pp. 663-671 ◽  
Author(s):  
Jiří Hanika ◽  
Vladimír Janoušek ◽  
Karel Sporka
Keyword(s):  
Effective Diffusion ◽  
Type System ◽  
Catalyst Particle ◽  
Ammonium Molybdate ◽  
Active Components ◽  
Model Set ◽  
Cobalt Dichloride ◽  
Set Up ◽  
Electron Microanalysis ◽  
Kinetics Of

Adsorption data for the impregnation of alumina with an aqueous solution of cobalt dichloride and ammonium molybdate were treated in terms of the Langmuir adsorption isotherm and compared with a mathematical model set up to describe the kinetics of simultaneous impregnation of a support by two components. The effective diffusion coefficients of the two components at 25 °C in a cylindrical particle of alumina were obtained. The validity of the model used was verified qualitatively by comparing the numerical results with the experimental time dependent concentration profiles of the active components in a catalyst particle, measured by electron microanalysis technique.

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