scholarly journals CFD Simulation and Experimental Measurements of Radon Distribution in a Traditional Hammam

2021 ◽  
Vol 39 (3) ◽  
pp. 963-968
Author(s):  
Rabi Rabi ◽  
Lhoucine Oufni ◽  
El-Hocine Youssoufi ◽  
Khamiss Cheikh ◽  
Hamza Badry ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Numerical Simulations ◽  
Indoor Air ◽  
Meteorological Parameters ◽  
Rate Increase ◽  
Cfd Simulation ◽  
Ventilation Rate ◽  
Maximum Deviation ◽  
Experimental Measurements ◽  
The Public

Radon natural is the main cause of lung cancer in non-smokers. Therefore, the study of the behavior of radon and its descendants in indoor air is of the highest importance, in order to limit the risk of radiation dose due to inhalation of radon by members of the public. This article focuses to study the effects of meteorological parameters on the concentration and distribution of radon in a traditional hammam by both numerical simulations and experiments. The results of the numerical simulations are qualitative and show that the concentration and distribution of radon decrease when the ventilation rate increase, as well as, when the temperature increases, however, it increases with the increase in relative humidity. The results obtained by the numerical simulations were in agreement with those obtained experimentally with a maximum deviation of 7%. Numerical simulations allow a better estimate of the distribution of radon in indoor air.

Experimental and Numerical Simulation for Thermal Investigation of Oscillating Heat Pipe Using VOF Model

2020 ◽  
Vol 38 (1A) ◽  
pp. 88-104
Author(s):  
Anwar S. Barrak ◽  
Ahmed A. M. Saleh ◽  
Zainab H. Naji
Keyword(s):  
Thermal Resistance ◽  
Heat Pipe ◽  
Heat Input ◽  
Cfd Simulation ◽  
Working Fluid ◽  
Maximum Deviation ◽  
Inlet Temperature ◽  
Maximum Heat ◽  
Oscillating Heat Pipe ◽  
Vof Model

This study is investigated the thermal performance of seven turns of the oscillating heat pipe (OHP) by an experimental investigation and CFD simulation. The OHP is designed and made from a copper tube with an inner diameter 3.5 mm and thickness 0.6 mm and the condenser, evaporator, and adiabatic lengths are 300, 300, and 210 mm respectively.  Water is used as a working fluid with a filling ratio of 50% of the total volume. The evaporator part is heated by hot air (35, 40, 45, and 50) oC with various face velocity (0.5, 1, and 1.5) m/s. The condenser section is cold by air at temperature 15 oC. The CFD simulation is done by using the volume of fluid (VOF) method to model two-phase flow by conjugating a user-defined function code (UDF) to the FLUENT code. Results showed that the maximum heat input is 107.75 W while the minimum heat is 13.75 W at air inlet temperature 35 oC with air velocity 0.5m/s. The thermal resistance decreased with increasing of heat input. The results were recorded minimum thermal resistance 0.2312 oC/W at 107.75 W and maximum thermal resistance 1.036 oC/W at 13.75W. In addition, the effective thermal conductivity increased due to increasing heat input.  The numerical results showed a good agreement with experimental results with a maximum deviation of 15%.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

Preemption in Public Health: The Dynamics of Clean Indoor Air Laws

2003 ◽  
Vol 31 (S4) ◽  
pp. 84-85 ◽  
Author(s):  
Elva Yañez ◽  
Gary Cox ◽  
Mike Cooney ◽  
Robert Eadie
Keyword(s):  
Public Health ◽  
Indoor Air ◽  
Tobacco Industry ◽  
Political Influence ◽  
Direct Result ◽  
Special Interest Groups ◽  
Policy Action ◽  
Local Public Health ◽  
The Public ◽  
City Councils

Preemption is a powerful strategy used by special interest groups to undermine strong, local public health standards. Currently, 20 states in the U.S. have preemption ordinances in place related to clean indoor air initiatives. These preemption laws are the direct result of an ongoing and aggressive campaign of tobacco companies to thwart clean indoor air initiatives, which ultimately, according to tobacco industry internal documents, cause significant reductions in their annual revenues. Clean indoor air policies have arisen from a greater understanding of the documented health risks associated with exposure to secondhand smoke and action by local government (city councils, county commissions, and boards of health) to protect the public from these hazards. The efforts of the tobacco industry undermine local authority and seek to shift policy action to the state and federal levels, where the industry has greater political influence.

Kitchen and Toilet of the Residence Exhaust Flow Field Analysis

2011 ◽  
Vol 354-355 ◽  
pp. 726-731
Author(s):  
Yue Ren Wang ◽  
Cong Xue ◽  
Jing Zhang
Keyword(s):  
Indoor Air ◽  
Cfd Simulation ◽  
Simulation Software ◽  
Field Analysis ◽  
Air Distribution ◽  
Volume Changes ◽  
Air Volume ◽  
Secondary Pollution ◽  
Comparison Results ◽  
Flow Field Analysis

Adopting the k-ε standard model, the CFD simulation software to simulate the indoor kitchen and toilet different row of indoor air volume air distribution in natural ventilated circumstance, by comparison results show that different row of indoor air volume changes in the rate of secondary pollution rate, and then to provide the change rule of indoor air quality protection reference basis.

scholarly journals Mathematical modeling and numerical simulation of heat dissipation in led bulbs

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1877-1884 ◽  
Author(s):  
Diego Alarcón ◽  
Eduardo. Balvís ◽  
Ricardo Bendaña ◽  
Alberto Conejero ◽  
de Fernández ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Numerical Simulation ◽  
Numerical Simulations ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Thermal Contact ◽  
Heat Sinks ◽  
Experimental Measurements ◽  
Heating And Cooling ◽  
The Common

We present a detailed study of heating and cooling processes in LED luminaires with passive heat sinks. Our analysis is supported by numerical simulations as well as experimental measurements, carried on commercial systems used for outdoor lighting. We have focused our analysis on the common case of a single LED source in thermal contact with an aluminum passive heat sink, obtaining an excellent agreement with experimental measurements and the numerical simulations performed. Our results can be easily expanded, without loss of generality, to similar systems.

scholarly journals Promoting early diagnosis and recovering from the COVID-19 pandemic in lung cancer through public awareness campaigns: learning from patient and public insight work

2021 ◽  
Vol 8 (1) ◽  
pp. e001120
Author(s):  
Matthew Evison ◽  
Sarah Taylor ◽  
Seamus Grundy ◽  
Anna Perkins ◽  
Michael Peake
Keyword(s):  
Lung Cancer ◽  
Early Diagnosis ◽  
Late Stage ◽  
Healthcare Professionals ◽  
Public Awareness ◽  
The Public ◽  
Awareness Campaigns ◽  
The North ◽  
The Common ◽  
Diagnosis Of Lung Cancer

COVID-19 has had a devastating impact on outcomes in lung cancer leading to later stage presentation, less curative treatment and higher mortality. This has amplified the existing problem of late-stage presentation in lung cancer and is a call to arms for a multifaceted strategy to address this, including public awareness campaigns to promote healthcare review in patients with persistent chest symptoms. We report the learning from patient and public insight work from across the North of England exploring the barriers to seeking healthcare review with persistent chest symptoms. Members of the public described how a lack of importance is placed on the common symptoms of lung cancer and a feeling of being unworthy of review by healthcare professionals. They would feel motivated to seek review by dispelling the nihilism of lung cancer and would be able to take action more easily by removing the logistical hassle in the process. We propose a four-pillar framework (validation–endorsement–motivation–action) for developing the content of any public awareness campaigns promoting early diagnosis of lung cancer based on the findings of this comprehensive insight work. All providers and commissioners must work together to overcome the perceived and real barriers to patients with persistent chest symptoms.

Multifidelity Recursive Cokriging for Dynamic Systems' Response Modification

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Luigi Bregant ◽  
Lucia Parussini ◽  
Valentino Pediroda
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Dynamic Systems ◽  
System Optimization ◽  
The Other ◽  
Experimental Measurements ◽  
Reciprocal Influence ◽  
Tests And Measurements ◽  
Invaluable Tool ◽  
Mixed Approach

In order to perform the accurate tuning of a machine and improve its performance to the requested tasks, the knowledge of the reciprocal influence among the system's parameters is of paramount importance to achieve the sought result with minimum effort and time. Numerical simulations are an invaluable tool to carry out the system optimization, but modeling limitations restrict the capabilities of this approach. On the other side, real tests and measurements are lengthy, expensive, and not always feasible. This is the reason why a mixed approach is presented in this work. The combination, through recursive cokriging, of low-fidelity, yet extensive, numerical model results, together with a limited number of highly accurate experimental measurements, allows to understand the dynamics of the machine in an extended and accurate way. The results of a controllable experiment are presented and the advantages and drawbacks of the proposed approach are also discussed.

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