Effect of Skylight Width on Natural Ventilation in Industrial Workshop

2012 ◽  
Vol 446-449 ◽  
pp. 2904-2907
Author(s):  
Ya Xin Su ◽  
Xin Wan ◽  
A Long Su
Keyword(s):  
Natural Ventilation ◽  
Waste Heat ◽  
Ventilation Rate ◽  
Heat Sources ◽  
Indoor Temperature ◽  
Hot Air ◽  
Temperature Environment ◽  
Computational Fluid Dynamics Cfd ◽  
Higher Temperature ◽  
Cfd Method

The authors numerically simulated the natural ventilation in an industrial workshop with heat sources by computational fluid dynamics (CFD) method and the effect of skylight size on the indoor temperature, ventilation rate and air flow patterns inside the workshop was discussed in detail. Realizable k- turbulent model was used to calculate the flow. Results show that a larger skylight width improves the ventilation. The average air temperature at operation zone decreases and the waste heat directly going into the operation zone decreases when the skylight width increases. The ventilation rate increases very slightly when the skylight width increases from 6 meters to 9 meters, while it increases sharply when w exceeds 10 meters. When the skylight width increases, more hot air is exhausted and the higher temperature environment in the upper zone of the workshop is improved.

Modeling of Buoyancy-Driven Natural Ventilation in Workshop: Optimization of Distance between Heat Source and Ground

2012 ◽  
Vol 170-173 ◽  
pp. 2579-2582 ◽  
Author(s):  
Ya Xin Su ◽  
A Long Su ◽  
Xin Wan
Keyword(s):  
Heat Source ◽  
Indoor Air ◽  
Energy Cost ◽  
Lower Energy ◽  
Natural Ventilation ◽  
Waste Heat ◽  
Heat Sources ◽  
Hot Air ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

Natural ventilation is suitable for application to workshops with heat sources to keep good indoor air quality at lower energy cost. In this paper, the authors numerically investigated the buoyancy-driven natural ventilation in a workshop with heat source based on computational fluid dynamics (CFD) method. The effect of the distance between heat source and ground on the air flow and temperature distribution was examined. Results showed that the average air temperature at operation zone could be effectively reduced when the distance between heat source and ground increased. The temperature field in the upper zone of the workshop was improved by diminishing the hot air zone near the ceiling and the waste heat directly going into the operation zone decreased when the distance between heat source and ground increased.

Numerical Simulation of the Natural Ventilation in Workshop with Different Air Inlet Openings

2011 ◽  
Vol 250-253 ◽  
pp. 3187-3190 ◽  
Author(s):  
Ya Xin Su ◽  
Xin Wan
Keyword(s):  
Natural Ventilation ◽  
Temperature Fields ◽  
Heat Distribution ◽  
Heat Sources ◽  
Distribution Factor ◽  
Discrete Ordinate ◽  
Air Inlet ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Inlet Opening

The authors numerically simulated the natural ventilation in an industrial workshop with heat sources by computational fluid dynamics (CFD) method when the height of air inlet opening was set different values. The flow and temperature fields in the workshop were simulated by realizable k-e turbulent model combined with a Discrete Ordinate (DO) radiation. Results showed the height of air inlet opening strongly influenced the flow and temperature fields in the workshop. When the height of air inlet opening increased, the natural ventilation was improved and more fresh air flowed into the workshop. When the height of air inlet opening increased from 1.7 meters to 3 meters, the temperature in the operation zone of the workshop dropped. When the height of air inlet opening increased from 2.7 meters to 3.7 meters, the temperature in operation zone did not change much, while the temperature in the upper zone of the workshop dropped. The heat distribution factor decreased first with the height of air inlet opening and then increased again. When the height of air inlet opening was 3 meters, the heat distribution factor was minimal.

Optimal Design of the External Respiration Double Skin Facade

2011 ◽  
Vol 374-377 ◽  
pp. 257-262
Author(s):  
Shi Feng ◽  
Wang Wei
Keyword(s):  
Optimal Design ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
External Respiration ◽  
Indoor Temperature ◽  
Temperature Changes ◽  
Indoor Thermal Environment ◽  
Double Skin ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

An optimal design is taken on the external respiration double skin facade (DSF) of a office building in Wuhan. The indoor thermal environment of the office units in the building have been simulated by taken computational fluid dynamics (CFD) method, and then the paper analyzes the indoor temperature changes under the condition that the internal airflow status of the DSF for natural ventilation, without shade, vents closed and other cases, discusses the influences of different inner glazed skin’s thermal properties, DSF for active ventilation and different wind speed on indoor thermal environment, according to the simulation results we obtain parameters of relevant optimal design.

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%.

scholarly journals ICCM2015: A Comparison of RANS and LES Computational Methods in Analyzing Ventilation Flow Through a Room Fitted with a Two-Sided Windcatcher

2017 ◽  
Vol 14 (03) ◽  
pp. 1750021 ◽  
Author(s):  
A. Niktash ◽  
B. P. Huynh
Keyword(s):  
Natural Ventilation ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Interior Space ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through ◽  
Cfd Method ◽  
Good Agreement

A windcatcher is a structure for providing natural ventilation using wind power; it is usually fitted on the roof of a building to exhaust the inside stale air to the outside and supplies the outside fresh air into the building interior space working by pressure difference between outside and inside of the building. In this paper, the behavior of free wind flow through a three-dimensional room fitted with a centered position two-canal bottom shape windcatcher model is investigated numerically, using a commercial computational fluid dynamics (CFD) software package and LES (Large Eddy Simulation) CFD method. The results have been compared with the obtained results for the same model but using RANS (Reynolds Averaged Navier–Stokes) CFD method. The model with its surrounded space has been considered in both method. It is found that the achieved results for the model from LES method are in good agreement with RANS method’s results for the same model.

Numerical Simulation of Campus Wind Environment

2010 ◽  
Vol 160-162 ◽  
pp. 280-286
Author(s):  
Ri Chao Liu ◽  
Zhong Hua Tang ◽  
Wei Yang Qi
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Wind Direction ◽  
Natural Ventilation ◽  
Pressure Field ◽  
Field Analysis ◽  
Wind Environment ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Rng Turbulence Model

This paper adopted computational fluid dynamics (CFD) method, used k-ε RNG turbulence model-closed control differential equations for numerical simulation. Through numerical simulation and analysis of wind environment in a middle school campus, the round wind field under dominant wind direction was got in the summer and winter. According to the results of velocity field and pressure field, analysis the wind environment, compared the influence of wind direction and surrounding buildings space to the natural ventilation, provided guidance introduce for the layout of the school.

Modeling of Natural Ventilation in Built-in Photovoltaic-Trombe Wall

2013 ◽  
Vol 448-453 ◽  
pp. 1537-1541 ◽  
Author(s):  
Xiao Wei Xu ◽  
Ya Xin Su
Keyword(s):  
Solar Radiation ◽  
Natural Ventilation ◽  
Reverse Flow ◽  
Volume Flow Rate ◽  
Ventilation Rate ◽  
Volume Flow ◽  
Channel Width ◽  
Air Volume ◽  
Trombe Wall ◽  
Cfd Method

The natural ventilation in a novel built-in photovoltaic-Trombe wall (BiPV-TW) was numerically simulated by CFD method. The effect of solar radiation and channel width on the airflow pattern and ventilation rate was analyzed. Results showed that the solar radiation and channel width influenced the ventilation rate remarkably. As the solar radiation increased, the ventilation rate increased. As the channel width increased from 0.1m to 0.4m, the ventilation rate monotonously increased. However, when the channel width exceeded 0.5m, the reverse flow was formed in the tope zone and the ventilation rate decreased. A maximum air volume flow rate was achieved when the channel width was approximately equal to 0.4m in a 3m tall model.

scholarly journals Natural Ventilation of Toilet Units in K–12 School Restrooms Using CFD

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4792
Author(s):  
Yi-Pin Lin
Keyword(s):  
Public Schools ◽  
Architectural Design ◽  
Natural Ventilation ◽  
Ventilation Rate ◽  
Design Parameters ◽  
Ventilation Efficiency ◽  
Computational Fluid Dynamics Cfd ◽  
Odor Pollution ◽  
Window Area ◽  
K 12

In this study, the influence of architectural design parameters (the exterior window area, the wall height at a corridor-side, and the door gap of a toilet unit) on the airflow patterns and malodorous volatile substance (acetic acid) distributions within toilet units were investigated via computational fluid dynamics (CFD), with the restrooms in K–12 public schools (kindergarten through grade 12) of Taiwan as research objects. The results show that when there is a 2 m/s north wind in winter, all the cases exceed the required 12 air changes per hour (ACH), and most are above 43.75 ACH. When there is a 0.5 m/s south wind in summer, nearly half of the cases fail to reach 12 ACH. Maintaining an adequate natural ventilation rate and an acceptable level of odor pollution through passive design and architectural design is difficult. Thinking about how to improve the ventilation efficiency of toilet units with the aid of simple, appropriate, and energy-saving mechanical ventilation approaches is necessary.

Simulation Study on Ventilation & Cooling for an Indoor Substation

2014 ◽  
Vol 672-674 ◽  
pp. 1700-1707 ◽  
Author(s):  
Rui Xu ◽  
Zhong Min Mei ◽  
Ting Fang Yu
Keyword(s):  
Natural Ventilation ◽  
Three Dimensional ◽  
Organization Design ◽  
Temperature Fields ◽  
Design Parameters ◽  
Air Distribution ◽  
Safety And Reliability ◽  
Computational Fluid Dynamics Cfd ◽  
Dimensional Simulation ◽  
Cfd Method

— Based on natural ventilation design scheme for an indoor substation, different air distribution schemes were obtained by changing height and size of air inlets and outlets. For indoor substation, three-dimensional simulation of air distribution was conducted by using Computational Fluid Dynamics (CFD) method. Ventilation & cooling effect of different indoor ventilation schemes were simulated with software (Fluent). By analyzing velocity fields and temperature fields, influences of different design parameters on safety and reliability of main transformer room of indoor substation were compared and analyzed in details. Additionally, characteristics and change rules of air distribution with different parameter variations were concluded. Considerations of ventilation organization design for main transformer room of indoor substation and recommendation for better air distribution schemes were provided. The research results also offered some guidance for design and renovation of ventilation & cooling projects of indoor substation.

Natural Ventilation in Workshop with Different Horizontal Arrangement of Heat Source

2012 ◽  
Vol 229-231 ◽  
pp. 2411-2414
Author(s):  
Ya Xin Su ◽  
Xin Wan
Keyword(s):  
Temperature Distribution ◽  
Heat Source ◽  
Natural Ventilation ◽  
Air Flow ◽  
Ventilation Rate ◽  
Pollutant Emission ◽  
Distribution Factor ◽  
Cfd Method ◽  
The Right ◽  
Horizontal Arrangement

The natural ventilation in a heating workshop with different horizontal arrangement of heat source was numerically simulated based on computational fluid dynamics (CFD) method. Realizable k- turbulent model was used to calculate the air flow and temperature distribution. Simulation results showed that the horizontal arrangement of the heat source in the workshop influenced heavily the air flow and temperature distribution. When the heat source was placed at the workshop centre, the heat distribution factor was minimal, the average air temperature at operation zone was lowest and the hot air exhausting velocity was highest, the air flow field and temperature distribution was reasonable for the natural ventilation. When the heat source was placed to be close to the air inlet opening, the fresh air would travel a short path and directly rise to exit and the fresh air did not reach to the right part of the workshop, leading to a possible accumulation of pollutant emission there. When the heat source was placed at the right side of the workshop, the benefit would be that the possible pollutant could be taken away by the air flow, however, the ventilation rate decreased.

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