Modeling of Indoor Air Quality and Comfort in the Tombs of Valley of the Kings

2005 ◽  
Author(s):  
Omar A. A. Abdel-Aziz ◽  
Essam E. Khalil
Keyword(s):  
Air Quality ◽  
Indoor Air ◽  
Three Dimensional ◽  
Design System ◽  
Wall Paintings ◽  
Governing Equations ◽  
Large Area ◽  
Air Velocity ◽  
Computational Fluid Dynamics Cfd ◽  
Selection Of

Airflow characteristics in ventilated and airconditioned spaces play an important role to attain comfort and hygiene conditions. This paper utilizes a 3D Computational Fluid Dynamics (CFD) model to assess the airflow characteristics in ventilated and air-conditioned archeological tombs of Egyptian Kings in the Valley of the Kings in Luxor, Egypt. It was found that the optimum airside design system can be attained, if the airflow is directed to pass all the enclosure areas before being extraction with careful selection of near wall velocities to avoid any wear or abrasion of the tomb-wall paintings. In this model conditioned air is allowed to enter the tomb from its entrance with a large area of admission in order to maintain low air velocity while extraction points are distributed along the tomb axis. The mode of evaluation should assess the airflow characteristics in any tomb passage according to its position in the enclosure and the thermal pattern and air quality. The Governing Equations are numerically solved in a three dimensional grid configurations at more than 500000 nodes. The paper addresses the various modeling aspects and constraints and suggests solutions that are viable and do not affect the tomb construction, interior nor sustainability.

CFD Modelling of Moisture Content, Air Velocity and Thermal Patterns in the Tombs of Horemeheb in Valley of Kings

2011 ◽  
Author(s):  
Essam E. Khalil
Keyword(s):  
Design System ◽  
Wall Paintings ◽  
Careful Selection ◽  
Cfd Model ◽  
Air Velocity ◽  
Cfd Modelling ◽  
Recirculation Zones ◽  
Computational Fluid Dynamics Cfd ◽  
Thermal Patterns ◽  
Selection Of

Airflow characteristics in ventilated and air-conditioned spaces play an important role to attain comfort and hygiene conditions. This paper utilizes a 3D Computational Fluid Dynamics (CFD) model to assess the airflow and relative humidity characteristics in ventilated and air-conditioned archaeological tomb of Horemheb in the Valley of the Kings in Luxor, Egypt. It is found that the best airside design system can be attained, if the airflow is directed to pass all the enclosure areas before the extraction with careful selection of near wall velocities to avoid any wear or aberration of the tomb-wall paintings. Still all factors and evaluation indices have the shortage to describe the influence of the recirculation zones on the occupancy zone of the visitors and also on the fresh supplied air. The mode of evaluation should assess the airflow characteristics in any tomb passage according to its position in the enclosure and the thermal pattern and air quality.

Flow Regimes and Heat Transfer Patterns in Archeological Climatized Church of Christ, Cairo

2012 ◽  
Author(s):  
Essam E. Khalil
Keyword(s):  
Heat Transfer ◽  
Church Of Christ ◽  
Design System ◽  
Wall Paintings ◽  
Careful Selection ◽  
Cfd Model ◽  
Thermal Pattern ◽  
Recirculation Zones ◽  
Computational Fluid Dynamics Cfd ◽  
Selection Of

Airflow characteristics in ventilated and air-conditioned spaces play an important role to attain comfort and hygiene conditions. This paper utilizes a 3D Computational Fluid Dynamics (CFD) model to assess the airflow characteristics in ventilated and air-conditioned archaeological Church of Christ (hanging Church) in Cairo, Egypt. It is found that the optimum airside design system can be attained, if the airflow is directed to pass all the enclosure areas before the extraction with careful selection of near wall velocities to avoid any wear or aberration of the wall paintings. Still all commonly known factors and evaluation indices have the shortage to describe the influence of the recirculation zones on the occupancy zone of the visitors and also on the fresh supplied air. The mode of evaluation should assess the airflow characteristics in any passage according to its position in the enclosure and the thermal pattern and air quality. The paper ends with brief discussion and concluding remarks.

scholarly journals Air Ventilation Performance of School Classrooms with Respect to the Installation Positions of Return Duct

2021 ◽  
Vol 13 (11) ◽  
pp. 6188
Author(s):  
Sungwan Son ◽  
Choon-Man Jang
Keyword(s):  
Air Quality ◽  
Numerical Analysis ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Three Dimensional ◽  
Cross Infection ◽  
School Students ◽  
Height Range ◽  
Air Ventilation ◽  
Ventilation Performance

For students, who spend most of their time in school classrooms, it is important to maintain indoor air quality (IAQ) to ensure a comfortable and healthy life. Recently, the ventilation performance for indoor air quality in elementary schools has emerged as an important social issue due to the increase in the number of days of continuous high concentrations of particulate matter. Three-dimensional numerical analysis has been introduced to evaluate the indoor airflow according to the installation location of return diffusers. Considering the possibility of the cross-infection of infectious diseases between students due to the direction of airflow in the classroom, the airflow angles of the average respiratory height range of elementary school students, between 1.0 and 1.5 m, are analyzed. Throughout the numerical analysis inside the classroom, it is found that the floor return system reduces the indoor horizontal airflow that causes cross-infection among students by 20% compared to the upper return systems. Air ventilation performance is also analyzed in detail using the results of numerical simulation, including streamlines, temperature and the age of air.

The Potential of Natural Ventilation in Single-Sided Ventilated Apartment to Improve Indoor Thermal Comfort and Air Quality

2011 ◽  
Author(s):  
M. F. Mohamed ◽  
M. Behnia ◽  
S. King ◽  
D. Prasad
Keyword(s):  
Air Quality ◽  
Thermal Comfort ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Natural Ventilation ◽  
Architectural Element ◽  
Flat Design ◽  
Effective Ventilation ◽  
Computational Fluid Dynamics Cfd ◽  
Ventilation Performance

Cross ventilation is a more effective ventilation strategy in comparison to single-sided ventilation. In the NSW Residential Flat Design Code1 (RFDC) the majority of apartments are required to adopt cross ventilation. However, in the case of studio and one-bedroom apartments, it is acknowledged that single-sided ventilation may prevail. Deep plan studio and one-bedroom apartments may achieve lower amenity of summer thermal comfort and indoor air quality where mechanical ventilation is not provided by air conditioning. Since compliance with the code may allow up to 40% of apartments in a development in Sydney to be single sided, it is important to understand the natural ventilation performance of such apartments. The objective of this paper is to investigate the natural ventilation potential in single-sided ventilated apartments to improve indoor air quality and thermal comfort. This investigation includes simulating various facade treatments involving multiple opening and balcony configurations. Balcony configurations are included in this study because, in Sydney, a balcony is a compulsory architectural element in any apartment building. The study uses computational fluid dynamics (CFD) software to simulate and predict the ventilation performance of each apartment configuration. This study suggests that properly configured balconies and openings can significantly improve indoor ventilation performance for enhanced indoor air quality and thermal comfort, by optimizing the available prevailing wind. However, it is important to note that inappropriately designed fac¸ade treatments also could diminish natural ventilation performance.

Turbine Airfoil Heat Transfer Predictions Using CFD

2005 ◽  
Author(s):  
Anil K. Tolpadi ◽  
James A. Tallman ◽  
Lamyaa El-Gabry
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulence Modeling ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Navier Stokes ◽  
Design System ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Airfoils ◽  
Typical Design

Conventional heat transfer design methods for turbine airfoils use 2-D boundary layer codes (BLC) combined with empiricism. While such methods may be applicable in the mid span of an airfoil, they would not be very accurate near the end-walls and airfoil tip where the flow is very three-dimensional (3-D) and complex. In order to obtain accurate heat transfer predictions along the entire span of a turbine airfoil, 3-D computational fluid dynamics (CFD) must be used. This paper describes the development of a CFD based design system to make heat transfer predictions. A 3-D, compressible, Reynolds-averaged Navier-Stokes CFD solver with k-ω turbulence modeling was used. A wall integration approach was used for boundary layer prediction. First, the numerical approach was validated against a series of fundamental airfoil cases with available data. The comparisons were very favorable. Subsequently, it was applied to a real engine airfoil at typical design conditions. A discussion of the features of the airfoil heat transfer distribution is included.

scholarly journals Study on Mechanism of Series-Flow of Pollutants between Consecutive Tunnels by Numerical Simulation

2019 ◽  
Vol 9 (19) ◽  
pp. 4125
Author(s):  
Honghu Zhang ◽  
Yunge Hou ◽  
Kaijie Wu ◽  
Tianhang Zhang ◽  
Ke Wu ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Velocity Ratio ◽  
Three Dimensional ◽  
Wall Jet ◽  
Air Velocity ◽  
Pressure Area ◽  
Computational Fluid Dynamics Cfd ◽  
Jet Theory ◽  
Jet Characteristics ◽  
Tunnel Entrance

The characteristics of series-flow between two consecutive tunnels with distance ranging from 20 m to 250 m are explored by computational fluid dynamics (CFD) parametric simulations of structure and operation parameters. The research indicates that series-flow can be considered the three-dimensional wall jet diffusion of upstream tunnel pollutants under the effects of the negative pressure area of the downstream tunnel entrance. The jet characteristics are primarily related to the tunnel distance between upstream and downstream tunnels and hydraulic diameters, and only influenced by the negative pressure in the area very close to downstream entrance where the tunnel air velocity ratio, i.e., the velocity of upstream tunnel air divided by the velocity of downstream tunnel air, decides the degree of the influence. If ignoring the effects of ambient wind and traffic flow, the series-flow ratio decreases with the increasing of parameters of the normalized tunnel distance, i.e., the tunnel distance divided by tunnel hydraulic diameter, and the tunnel air velocity ratio. Based on the three-dimensional wall jet theory, a series-flow model covering all jet characteristic sections is built. The experiment results indicate that the model applies to consecutive tunnels with any spacing and exhibits higher prediction accuracy.

Numerical Simulation of Flow Process of Ammonium Persulfate Crystallizer

2014 ◽  
Vol 997 ◽  
pp. 396-400
Author(s):  
Yu Guang Fan ◽  
Ting Wei
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Three Dimensional ◽  
Ammonium Persulfate ◽  
Flow Process ◽  
Calculation Results ◽  
Crystallization Effect ◽  
Computational Fluid Dynamics Cfd ◽  
The Impact ◽  
Selection Of

The method of computational fluid dynamics (CFD) is used to three-dimensional numerical simulation for the fluid flow process of ammonium persulfate crystallizer. By using standard model, this paper respectively simulated the flow field within the crystallizer in the impeller installation height of 1.2 m while stirring speed is of 60 r/min, 100 r/min and 200 r/min; and simulated the impact of the flow field inside the crystallizer when the stirring speed of 100 r/min and impeller installation height respectively is of 0.7 m, 1.2 m and 1.7 m. That calculation results show that: the velocity gradient is mainly concentrated in the area of internal draft tube and paddle around. With the increase of impeller speed, the flow velocity of the fluid within the crystallizer corresponding increases; and the energy also gradually decreases from mixing impeller to the settlement zone with the loss of the installation height, and the kinetic energy in the bottom of the crystallizer is reduced. Considering the energy and crystallization effect, selection of mixing speed of 100 r/min or so and installation height of about 1.2 m is more appropriate.

scholarly journals INVESTIGATING INDOOR AIR QUALITY AND THERMAL COMFORT USING DIFFERENT VENTILATION SYSTEMS UNDER IRAQI CLIMATE

2018 ◽  
Vol 18 (3) ◽  
pp. 422-435
Author(s):  
Ala'a A Mahdi ◽  
Sara Abbas
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Indoor Environment ◽  
Simulation Models ◽  
Air Distribution ◽  
Airflow Rate ◽  
Computational Fluid Dynamics Cfd ◽  
Occupied Zone ◽  
Ventilation Systems

Computational Fluid Dynamics (CFD) of indoor environment as well as qualityconsiderations are important element in the study of energy consumption, thermal comfortand indoor air quality in buildings. This paper investigate a comparison work betweenimpinging jet, displacement, and mixing ventilation systems for an isothermal and nonisothermalventilated room for Indoor Air Quality (IAQ) and thermal human comfort underIraqi climate. For IJV system, draught discomfort is the issue of most concern since itsupplies cooled air directly to the occupied zone. This study investigated a number of factorsinfluencing draught discomfort and temperature stratification in an office environment. Theconsidered factors, supply airflow rate and supply air temperature. RNG K-? turbulencemodel was used with the turbulent flow. The second aspect included numerical analyses byadopting ANSYS FLUENT15 code to generate simulation models. A square shaped airsupply device was used with [0.1 times room height (h)] outlet terminal height from the footlevel end. The IJV system proved more efficient than displacement and mixing ventilationsystems. The Air Distribution Performance Index (ADPI) obtained for an isothermal andnon-isothermal ventilated room adopting IJV system gave best values (0.80, 0.83)respectively compared with the other two ventilation systems.

scholarly journals Performance of Calcium Chloride and Silica Gel as Solid Desiccant Dehumidifiers for Indoor Air Quality

2021 ◽  
Vol 88 (3) ◽  
pp. 57-70
Author(s):  
Nur Kamila Ramli ◽  
Yusri Yusup ◽  
Christabel Lam Pei Lin ◽  
Baharin Azahari ◽  
Mardiana Idayu Ahmad
Keyword(s):  
Air Quality ◽  
Relative Humidity ◽  
Indoor Air Quality ◽  
Calcium Chloride ◽  
Silica Gel ◽  
Indoor Air ◽  
Airborne Bacteria ◽  
Air Velocity ◽  
Ability Test ◽  
Test Room

Desiccant materials are recently discovered as a viable alternative in dehumidification technology due to their naturally hygroscopic qualities and minimal energy requirement. This paper discusses the performance of four brand samples of selected desiccants used for dehumidification. In this study, dehumidification ability and indoor air quality (IAQ) tests were carried out. The dehumidification ability test was conducted in a controlled environmental chamber at a temperature of 25°C, relative humidity of 70%, and air velocity of 2 m/s for 45-minute session. Meanwhile, the IAQ test was carried out in a naturally ventilated test room, and six IAQ parameters (relative humidity, air velocity, air temperature, particulate matter (PM10), airborne bacteria and carbon dioxide (CO2) were studied. The IAQ test was performed for five different conditions: control, application of brand samples A, B, C and D in the test room. From this study, it was found, brand A (0.6823 g/kg) and brand B (0.6849 g/kg) had a relatively good dehumidification ability during the 45-minute dehumidification ability test compared to brand C (0.3108 g/kg) and brand D (0.3982 g/kg). The IAQ test revealed that brand A had the biggest variation in indoor-outdoor relative humidity of 13.12%, while brand D had the smallest difference of 11.83%. Brand B had the highest average PM10 concentration of 0.037 μg/m3. The airborne bacterial count for all conditions had no statistical significance, indicating the application of desiccants were not effective in reducing airborne bacteria. From this study, it can be concluded that calcium chloride (brand A and B) samples performed better than silica gel (brand C and D) samples in terms of dehumidification ability and IAQ profile.

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