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Prof. of mechanical engineering and renewable energy
Project Goal: Development of Sustainable Buildings and Green Infrastructure in Saudi Arabia
Current Stage: Paper publications
Project Goal: Development of green healthcare facilities
Current Stage: Paper publications
Globally, there has been a remarkable growth in the number of underground constructions (UGC) such as railways, offices, hospitals and shopping malls. This expansion is a result of urban area extensions that are limited by the availability of buildable land. Underground construction can also be used to protect people from the harshness of the outdoor conditions. The aim of this research is to investigate the impact of underground construction in hot regions. The major issue with most of the current UGC is the lack of natural ventilation and daylight. This has a clear negative impact on the user’s perception and comfort. The new design elevates the external walls to place some of the windows above ground for the purpose of natural ventilation and providing a view. The study conducted an experiment using an underground room enhanced with field measurements to ascertain the indoor temperature as well as relative humidity. In addition, the study used an energy simulation to calculate building heat transfer and solar heat gain. It was revealed that the use of UGC in hot regions promoted with the addition of natural ventilation can lower the indoor temperature by 3 °C in summer.
Mamdooh Alwetaishi; Omrane Benjeddou; Ashraf Balabel; Ali Alzaed. Can Underground Buildings Be Beneficial in Hot Regions? An Investigation of Field Measurements in On-Site Built Underground Construction. Buildings 2021, 11, 341 .
AMA StyleMamdooh Alwetaishi, Omrane Benjeddou, Ashraf Balabel, Ali Alzaed. Can Underground Buildings Be Beneficial in Hot Regions? An Investigation of Field Measurements in On-Site Built Underground Construction. Buildings. 2021; 11 (8):341.
Chicago/Turabian StyleMamdooh Alwetaishi; Omrane Benjeddou; Ashraf Balabel; Ali Alzaed. 2021. "Can Underground Buildings Be Beneficial in Hot Regions? An Investigation of Field Measurements in On-Site Built Underground Construction." Buildings 11, no. 8: 341.
This paper discusses in detail the current level of awareness of the Saudi Arabia stakeholders regarding the use and application of green building rating systems. The paper used a mix of qualitative and quantitative research methods through an exploratory method that utilized an online survey targeting experts and construction stakeholders to fill the gap of previous research papers and support the argument of the increase in the level of the awareness of stakeholders in the use and application of green building rating systems in Saudi Arabia. This research aims to focus on the level of awareness of the Saudi construction market stakeholders on green building rating systems in Saudi Arabia with focus on the Leadership in Energy and Environmental Design system LEED and Mostadam. It also investigated which rating system responds to the need of the Saudi construction market with regard to energy conservation and water consumption more effectively. The methodology utilized in this research used a combination of primary and secondary data where the primary data were a survey sent to Saudi construction stakeholders where a total of 1320 respondents participated in the survey. Results from this research showed a promising number of agreements between the participating stakeholders to the level of awareness of green building rating systems in Saudi Arabia and to the willingness to use internationally recognized rating systems such as LEED and the use of locally recognized systems such as Mostadam. Furthermore, the research aims to link the results with the Sustainable Development Goals (SDGs) with a focus on SDGs 6 and 7. The results show a high level of appreciation and agreement to the importance of energy and water conservation in green buildings that will be using either LEED or Mostadam in Saudi Arabia and accomplish the targets outlined under the SDGs.
Mohammed Al-Surf; Ashraf Balabel; Mamdooh Alwetaishi; Ahmed Abdelhafiz; Usama Issa; Ibrahim Sharaky; Amal Shamseldin; Mosleh Al-Harthi. Stakeholder’s Perspective on Green Building Rating Systems in Saudi Arabia: The Case of LEED, Mostadam, and the SDGs. Sustainability 2021, 13, 8463 .
AMA StyleMohammed Al-Surf, Ashraf Balabel, Mamdooh Alwetaishi, Ahmed Abdelhafiz, Usama Issa, Ibrahim Sharaky, Amal Shamseldin, Mosleh Al-Harthi. Stakeholder’s Perspective on Green Building Rating Systems in Saudi Arabia: The Case of LEED, Mostadam, and the SDGs. Sustainability. 2021; 13 (15):8463.
Chicago/Turabian StyleMohammed Al-Surf; Ashraf Balabel; Mamdooh Alwetaishi; Ahmed Abdelhafiz; Usama Issa; Ibrahim Sharaky; Amal Shamseldin; Mosleh Al-Harthi. 2021. "Stakeholder’s Perspective on Green Building Rating Systems in Saudi Arabia: The Case of LEED, Mostadam, and the SDGs." Sustainability 13, no. 15: 8463.
Saudi Arabia is one of the most important countries that have an abundant potential of renewable energy resources in form of solar and wind energy. In light of Saudi Arabia's vision 2030, renewable energy should fractionally replace fossil fuel in energy production during the different aspects of life in the next few years. As a result of the distinguished geographical location of Saudi Arabia, in the sun-belt zone, solar energy projects have contributed to a wide field during the past few years in smart city projects as well as sustainable building initiatives. Most of the solar energy applications in Saudi Arabia's sustainable buildings have been directed to solar thermal and photovoltaic technologies. However, the utilization of passive solar daylighting systems in Saudi Arabia's sustainable buildings has received little attention, although it can save about 20–30% of the total electrical energy consumed. Recently, Solatube technology has received great attention globally due to the positive environmental impact and the resulting internal health conditions. Solatube system can transport efficiently the daylight into the interior spaces and achieve visual comfort without excessive heat. In the present paper, the potential of Solatube technology in Saudi Arabia's sustainable building sectors is evaluated and the required climate conditions are discussed. Different other aspects will be also discussed related to the Solatube daylight systems such as the different types of Solatube systems, the different applications of Solatube daylight systems, and the illustration of the previous case studies of Solatube daylight systems in different countries. In general, it is concluded that Saudi Arabia as one of the largest solar energy producers and has widespread desert land and year-round clear sky is very suitable for adopting Solatube technology in different sustainable building sectors.
A. Balabel; M. Alwetaishi; A. Abdelhafiz; U. Issa; I.A. Sharaky; A.K. Shamseldin; M. Al-Surf; M. Al-Harthi. Potential of Solatube technology as passive daylight systems for sustainable buildings in Saudi Arabia. Alexandria Engineering Journal 2021, 61, 339 -353.
AMA StyleA. Balabel, M. Alwetaishi, A. Abdelhafiz, U. Issa, I.A. Sharaky, A.K. Shamseldin, M. Al-Surf, M. Al-Harthi. Potential of Solatube technology as passive daylight systems for sustainable buildings in Saudi Arabia. Alexandria Engineering Journal. 2021; 61 (1):339-353.
Chicago/Turabian StyleA. Balabel; M. Alwetaishi; A. Abdelhafiz; U. Issa; I.A. Sharaky; A.K. Shamseldin; M. Al-Surf; M. Al-Harthi. 2021. "Potential of Solatube technology as passive daylight systems for sustainable buildings in Saudi Arabia." Alexandria Engineering Journal 61, no. 1: 339-353.
Saudi Arabia vision 2030 emphasizes the applications of sustainability concepts in all aspects of life in Saudi society. Accordingly, the Mostadam rating system for existing and new buildings was recently launched to achieve appropriate, sustainable building standards. In the medical field, sustainable healthcare facilities are an extension of the concept of sustainable buildings in terms of important sustainable healthcare parameters. Therefore, the sustainable development of healthcare facilities has great impacts on growing economic, social and environmental issues, which, in turn, improve Saudi society’s public health. Moreover, the COVID-19 pandemic has further exposed the urgent need for sustainable healthcare facilities to control the outbreak of such dangerous pandemics. Accordingly, the retrofitting of the existing healthcare facilities and the shift toward new sustainable ones have become an important objective of many countries worldwide. Currently, the concepts related to sustainable healthcare facilities are rapidly varying their scopes toward wider perspectives. Therefore, a new local rating system for healthcare facilities based on the potential and resources of sustainable healthcare facilities in Saudi Arabia should be developed. The present paper investigates the development of a new version of the Mostadam rating system, known here as “Mostadam-HCF”, in relation to the local Mostadam rating system and in accordance with the LEED version 4.1 (BD + C: Health-care). This important step can help the existing and the new healthcare facilities in Saudi Arabia to obtain, firstly, national accreditation and, consequently, to be internationally accredited. Moreover, the initiative of sustainable healthcare facilities can also help in fighting the current COVID-19 pandemic and the other possible future viruses in Saudi Arabia.
Ashraf Balabel; Mamdooh Alwetaishi. Toward Sustainable Healthcare Facilities: An Initiative for Development of “Mostadam-HCF” Rating System in Saudi Arabia. Sustainability 2021, 13, 6742 .
AMA StyleAshraf Balabel, Mamdooh Alwetaishi. Toward Sustainable Healthcare Facilities: An Initiative for Development of “Mostadam-HCF” Rating System in Saudi Arabia. Sustainability. 2021; 13 (12):6742.
Chicago/Turabian StyleAshraf Balabel; Mamdooh Alwetaishi. 2021. "Toward Sustainable Healthcare Facilities: An Initiative for Development of “Mostadam-HCF” Rating System in Saudi Arabia." Sustainability 13, no. 12: 6742.
Improving building performance through reducing negative environmental impacts can be achieved by greening existing buildings (GEB), which is considered a very important sustainability process. Due to the risky and uncertain nature of the process of GEB, a growing amount of attention should be given to eliminating the effects of risks on GEB. This research aims to identify most expected risk factors related to GEB, as well as to evaluate their effects through calculating risk factor characteristics, such as risk factor presence (RFP), impact on the GEB process (IGEB), and impact on building performance in the long run (IBP), as new indices describe these risks. Sixty-six risk factors were categorized in seven risk groups related to the economic aspect, social aspect, environmental aspect, managerial aspect, sustainability operation, sustainable design, and renovation. Moreover, a fuzzy model for risk analysis was developed to combine the multi-effects of the aforementioned three risk factor characteristics in one index representing the risk factors’ overall importance. The model was applied and verified for data collected in Saudi Arabia. The results of this study showed that the most important risk group is the greening process of environmental control, while the least important is the greening process of renovation and construction. Using the proposed model improved the results of evaluating risks affecting GEB through merging the multi-effects of risk factor characteristics. The results and analysis proved that the most important key risk factors were environmental in nature. An intricate relationship of the impacts on the GEB process and building performance with the overall importance of the risk factors was clearly found. The decision makers who deal with greening projects in Saudi Arabia should be aware of the key risks identified in this study. The proposed methodology and model can be easily applied to other countries to help decision makers in evaluating their GEB projects, as well as comparing more greening projects based on risk analysis.
Usama Issa; Ibrahim Sharaky; Mamdooh Alwetaishi; Ashraf Balabel; Amal Shamseldin; Ahmed Abdelhafiz; Mohammed Al-Surf; Mosleh Al-Harthi; Medhat Osman. Developing and Applying a Model for Evaluating Risks Affecting Greening Existing Buildings. Sustainability 2021, 13, 6403 .
AMA StyleUsama Issa, Ibrahim Sharaky, Mamdooh Alwetaishi, Ashraf Balabel, Amal Shamseldin, Ahmed Abdelhafiz, Mohammed Al-Surf, Mosleh Al-Harthi, Medhat Osman. Developing and Applying a Model for Evaluating Risks Affecting Greening Existing Buildings. Sustainability. 2021; 13 (11):6403.
Chicago/Turabian StyleUsama Issa; Ibrahim Sharaky; Mamdooh Alwetaishi; Ashraf Balabel; Amal Shamseldin; Ahmed Abdelhafiz; Mohammed Al-Surf; Mosleh Al-Harthi; Medhat Osman. 2021. "Developing and Applying a Model for Evaluating Risks Affecting Greening Existing Buildings." Sustainability 13, no. 11: 6403.
In this study, the recycled concrete aggregates and powder (RCA and RCP) prepared from basaltic concrete waste were used to replace the natural aggregate (NA) and cement, respectively. The NA (coarse and fine) was replaced by the recycled aggregates with five percentages (0%, 20%, 40%, 60% and 80%). Consequently, the cement was replaced by the RCP with four percentages (0%, 5%, 10% and 20%). Cubes with 100 mm edge length were prepared for all tests. The compressive and tensile strengths (fcu and ftu) and water absorption (WA) were investigated for all mixes at different ages. Partial substitution of NA with recycled aggregate reduced the compressive strength with different percentages depending on the type and source of recycled aggregate. After 28 days, the maximum reduction in fcu value was 9.8% and 9.4% for mixtures with coarse RCA and fine RCA (FRCA), respectively. After 56 days, the mixes with 40% FRCA reached almost the same fcu value as the control mix (M0, 99.5%). Consequently, the compressive strengths of the mixes with 10% RCA at 28 and 56 days were 99.3 and 95.2%, respectively, compared to those of M0. The mixes integrated FRCA and RCP showed higher tensile strengths than the M0 at 56 d with a very small reduction at 28 d (max = 3.4%). Moreover, the fcu and ftu values increased for the late test ages, while the WA decreased.
Ibrahim Sharaky; Usama Issa; Mamdooh Alwetaishi; Ahmed Abdelhafiz; Amal Shamseldin; Mohammed Al-Surf; Mosleh Al-Harthi; Ashraf Balabel. Strength and Water Absorption of Sustainable Concrete Produced with Recycled Basaltic Concrete Aggregates and Powder. Sustainability 2021, 13, 6277 .
AMA StyleIbrahim Sharaky, Usama Issa, Mamdooh Alwetaishi, Ahmed Abdelhafiz, Amal Shamseldin, Mohammed Al-Surf, Mosleh Al-Harthi, Ashraf Balabel. Strength and Water Absorption of Sustainable Concrete Produced with Recycled Basaltic Concrete Aggregates and Powder. Sustainability. 2021; 13 (11):6277.
Chicago/Turabian StyleIbrahim Sharaky; Usama Issa; Mamdooh Alwetaishi; Ahmed Abdelhafiz; Amal Shamseldin; Mohammed Al-Surf; Mosleh Al-Harthi; Ashraf Balabel. 2021. "Strength and Water Absorption of Sustainable Concrete Produced with Recycled Basaltic Concrete Aggregates and Powder." Sustainability 13, no. 11: 6277.
Recently, increased attention has been given to the coupling of computational fluid dynamics (CFD) with the fuzzy logic control system for obtaining the optimum prediction of many complex engineering problems. The data provided to the fuzzy system can be obtained from the accurate computational fluid dynamics of such engineering problems. Windcatcher performance to achieve thermal comfort conditions in buildings, especially in hot climate regions, is considered as one such complex problem. Windcatchers can be used as natural ventilation and passive cooling systems in arid and windy regions in Saudi Arabia. Such systems can be considered as the optimum solution for energy-saving and obtaining thermal comfort in residential buildings in such regions. In the present paper, three-dimensional numerical simulations for a newly-developed windcatcher model have been performed using ANSYS FLUENT-14 software. The adopted numerical algorithm is first validated against previous experimental measurements for pressure coefficient distribution. Different turbulence models have been firstly applied in the numerical simulations, namely, standard k-epsilon model (1st and 2nd order), standard Wilcox k-omega model (1st and 2nd order), and SST k-omega model. In order to assess the accuracy of each turbulence model in obtaining the performance of the proposed model of the windcatcher system, it is found that the second order k-epsilon turbulence model gave the best results when compared with the previous experimental measurements. A new windcatcher internal design is proposed to enhance the ventilation performance. The fluid dynamics characteristics of the proposed model are presented, and the ventilation performance of the present model is estimated. The numerical velocity profiles showed good agreement with the experimental measurements for the turbulence model. The obtained results have shown that the second order k-epsilon turbulence can predict the different important parameters of the windcatcher model. Moreover, the coupling algorithm of CFD and the fuzzy system for obtaining the optimum operating parameters of the windcatcher design are described.
Ashraf Balabel; Mohammad Faizan; Ali Alzaed. Towards a Computational Fluid Dynamics-Based Fuzzy Logic Controller of the Optimum Windcatcher Internal Design for Efficient Natural Ventilation in Buildings. Mathematical Problems in Engineering 2021, 2021, 1 -10.
AMA StyleAshraf Balabel, Mohammad Faizan, Ali Alzaed. Towards a Computational Fluid Dynamics-Based Fuzzy Logic Controller of the Optimum Windcatcher Internal Design for Efficient Natural Ventilation in Buildings. Mathematical Problems in Engineering. 2021; 2021 ():1-10.
Chicago/Turabian StyleAshraf Balabel; Mohammad Faizan; Ali Alzaed. 2021. "Towards a Computational Fluid Dynamics-Based Fuzzy Logic Controller of the Optimum Windcatcher Internal Design for Efficient Natural Ventilation in Buildings." Mathematical Problems in Engineering 2021, no. : 1-10.
Coronavirus disease 2019 (COVID-19) continues to spread rapidly all over the world challenging nearly all governments. The exact nature of COVID-19’s spread and risk factors for such a rapid spread are still imprecise as available data depend on confirmed cases only. This may result in an asymmetrically distributed burden among countries. There is an urgent need for developing a new technique or model to identify and analyze risk factors affecting such a spread. Fuzzy logic appears to be suitable for dealing with multi-risk groups with undefined data. The main purpose of this research was to develop a risk analysis model for COVID-19’s spread evaluation. Other objectives included identifying such risk factors aiming to find out reasons for such a fast spread. Nine risk groups were identified and 46 risk factors were categorized under these groups. The methodology in this study depended on identifying each risk factor by its probability of occurrence and its impact on viruses spreading. Many logical rules were used to support the proposed risk analysis model and represented the relation between probabilities and impacts as well as to connect other risk factors. The model was verified and applied in Saudi Arabia with further probable use in similar conditions. Based on the model results, it was found that (daily activities) and (home isolation) are considered groups with highest risk. On the other hand, many risk factors were categorized with high severity such as (poor social distance), (crowdedness) and (poor personal hygiene practices). It was demonstrated that the impact of COVID-19’s spread was found with a positive correlation with the risk factors’ impact, while there was no association between probability of occurrence and impact of the risk factors on COVID-19’s spread. Saudi Arabia’s quick actions have greatly reduced the impact of the risks affecting COVID-19’s spread. Finally, the new model can be applied easily in most countries to help decision makers in evaluating and controlling COVID-19’s spread.
Usama Issa; Ashraf Balabel; Mohammed Abdelhakeem; Medhat Osman. Developing a Risk Model for Assessment and Control of the Spread of COVID-19. Risks 2021, 9, 38 .
AMA StyleUsama Issa, Ashraf Balabel, Mohammed Abdelhakeem, Medhat Osman. Developing a Risk Model for Assessment and Control of the Spread of COVID-19. Risks. 2021; 9 (2):38.
Chicago/Turabian StyleUsama Issa; Ashraf Balabel; Mohammed Abdelhakeem; Medhat Osman. 2021. "Developing a Risk Model for Assessment and Control of the Spread of COVID-19." Risks 9, no. 2: 38.
Saudi Arabia vision 2030 adopts comprehensive development standards in all fields of Saudi society. To achieve such standards, many initiatives and programs have been launched to achieve sustainable goals while meeting the needs of the present without compromising the requirements of future generations. Sustainable buildings are highly important in achieving sustainable development goals due to their excellent ability to reduce energy consumption, increase building efficiency, and reduce harmful emissions of greenhouse gases. The Kingdom aims to be the largest investor in the world in the sustainable buildings sector. To this end, the “Mostadam” evaluation service was recently launched in order to assist existing and new buildings in achieving sustainable building standards in a way that is in keeping with the privacy and principles of Saudi society. The present paper presents an extensive investigation to assess the current state of sustainable buildings in Saudi cities. Moreover, the main categories of sustainable residential buildings according to the “Mostadam” rating systems are discussed, and the potential of such categories in Saudi Arabia is explored. Finally, suggestions are given for some practical strategies and future policies targeting the total transformation towards sustainable buildings and, consequently, towards sustainable cities. This will have a great impact on achieving comprehensive sustainable development in Saudi Arabia in line with vision 2030.
Ashraf Balabel; Mamdooh Alwetaishi. Towards Sustainable Residential Buildings in Saudi Arabia According to the Conceptual Framework of “Mostadam” Rating System and Vision 2030. Sustainability 2021, 13, 793 .
AMA StyleAshraf Balabel, Mamdooh Alwetaishi. Towards Sustainable Residential Buildings in Saudi Arabia According to the Conceptual Framework of “Mostadam” Rating System and Vision 2030. Sustainability. 2021; 13 (2):793.
Chicago/Turabian StyleAshraf Balabel; Mamdooh Alwetaishi. 2021. "Towards Sustainable Residential Buildings in Saudi Arabia According to the Conceptual Framework of “Mostadam” Rating System and Vision 2030." Sustainability 13, no. 2: 793.
Along with the global concern of the Environmental Assessment of Buildings, the Kingdom of Saudi Arabia (KSA) had recently used its system, Mostadam, to provide a suitable method to assess its buildings environmentally. Nevertheless, Mostadam still cannot be used for all Saudi Arabia regions without having misleading results, which is due to its various internal regions with their various characteristics. Taif city has its unique environmental characteristics, which affect all the environmental buildings’ assessment fields. This research aimed to adjust the Indoor Environmental Quality (IEQ) field of Mostadam according to Taif characteristics. The research analyzed Taif characteristics that have an impact on the IEQ field, which are mainly related to the occupants’ different comfort needs and health requirements. Then, according to an analytical methods, authors proposed some changes to adjust Mostadam IEQ field according to these characteristics. The research resulted in an obvious difference between the resulted IEQ items weights and formulation versus the origin one of Mostadam, which proves the need for such adjustment to achieve a fair and trusted assessment to achieve the utmost credible assessment results when assessing buildings environmentally in Taif. It is recommended to adjust other assessment fields similarly later on, and then globally.
Amal Shamseldin; Ashraf Balabel; Mamdooh Alwetaishi; Ahmed Abdelhafiz; Usama Issa; Ibrahim Sharaky; Mohamed Al-Surf; Mosleh Al-Harthi. Adjustment of the Indoor Environmental Quality Assessment Field for Taif City-Saudi Arabia. Sustainability 2020, 12, 10275 .
AMA StyleAmal Shamseldin, Ashraf Balabel, Mamdooh Alwetaishi, Ahmed Abdelhafiz, Usama Issa, Ibrahim Sharaky, Mohamed Al-Surf, Mosleh Al-Harthi. Adjustment of the Indoor Environmental Quality Assessment Field for Taif City-Saudi Arabia. Sustainability. 2020; 12 (24):10275.
Chicago/Turabian StyleAmal Shamseldin; Ashraf Balabel; Mamdooh Alwetaishi; Ahmed Abdelhafiz; Usama Issa; Ibrahim Sharaky; Mohamed Al-Surf; Mosleh Al-Harthi. 2020. "Adjustment of the Indoor Environmental Quality Assessment Field for Taif City-Saudi Arabia." Sustainability 12, no. 24: 10275.
The study investigated the level of thermal comfort in historical buildings located at a relatively high altitude in the Arabian Desert of Saudi Arabia. The study focused on the impact of the use of thermal mass and orientation on the level of thermal performance at Shubra and Boqri Palaces. Qualitative and quantitative analyses were used in this study, including a questionnaire interview with architecture experts living at the relatively high altitude of Taif city, to obtain data and information from local experts. The computer software TAS EDSL was used along with on-site equipment, such as thermal imaging cameras and data loggers, to observe the physical conditions of the building in terms of its thermal performance. The study revealed that the experts’ age and years of experience were important aspects while collecting data from them during the survey. The use of thermal mass had a slight impact on the indoor air temperature as well as the energy consumption, but it helped in providing thermal comfort. Use of ventilation can improve thermal comfort level. Evaporative cooling technique has a considerable impact on reducing indoor air temperature with 4 °C drop, improving the thermal comfort sensation level. The novelty of this work is that, it links the outcomes of qualitative results of experts with field monitoring as well as computer modelling. This can contribute as method to accurately collect data in similar case studies.
Mamdooh Alwetaishi; Ashraf Balabel; Ahmed Abdelhafiz; Usama Issa; Ibrahim Sharaky; Amal Shamseldin; Mohammed Al-Surf; Mosleh Al-Harthi; Mohamed Gadi. User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation. Sustainability 2020, 12, 9672 .
AMA StyleMamdooh Alwetaishi, Ashraf Balabel, Ahmed Abdelhafiz, Usama Issa, Ibrahim Sharaky, Amal Shamseldin, Mohammed Al-Surf, Mosleh Al-Harthi, Mohamed Gadi. User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation. Sustainability. 2020; 12 (22):9672.
Chicago/Turabian StyleMamdooh Alwetaishi; Ashraf Balabel; Ahmed Abdelhafiz; Usama Issa; Ibrahim Sharaky; Amal Shamseldin; Mohammed Al-Surf; Mosleh Al-Harthi; Mohamed Gadi. 2020. "User Thermal Comfort in Historic Buildings: Evaluation of the Potential of Thermal Mass, Orientation, Evaporative Cooling and Ventilation." Sustainability 12, no. 22: 9672.
This paper investigates theoretically and experimentally the optimum operating conditions for alkaline water electrolysis coupled with a solar photovoltaic (PV) source for hydrogen generation with emphasis on the electrolyzer efficiency under different operating conditions. The PV generator is simulated using Matlab/Simulink to obtain its characteristics under different operating conditions with solar irradiance and temperature variations. A wide range of operating parameters, which include input voltage, temperature, concentration of the electrolyte, and distance between the electrodes, are considered, and their effects on the efficiency of hydrogen production process are explored. A group of performance curves for the solar-hydrogen energy system (SHES) under a wide range of operating conditions are obtained through a number of individual experimental measurements. The optimum operating conditions, which correspond to the maximum electrolyzer efficiency, are determined for the proposed SHES. The effects of the ambient temperature and the electrolyte temperature on the performance of the solar PV energy system and the hydrogen production process are also investigated.
Ashraf Balabel; Mohamed S. Zaky; Ismail Sakr. Optimum Operating Conditions for Alkaline Water Electrolysis Coupled with Solar PV Energy System. Arabian Journal for Science and Engineering 2014, 39, 4211 -4220.
AMA StyleAshraf Balabel, Mohamed S. Zaky, Ismail Sakr. Optimum Operating Conditions for Alkaline Water Electrolysis Coupled with Solar PV Energy System. Arabian Journal for Science and Engineering. 2014; 39 (5):4211-4220.
Chicago/Turabian StyleAshraf Balabel; Mohamed S. Zaky; Ismail Sakr. 2014. "Optimum Operating Conditions for Alkaline Water Electrolysis Coupled with Solar PV Energy System." Arabian Journal for Science and Engineering 39, no. 5: 4211-4220.
The present paper introduces a new interfacial marker-level set method (IMLS) which is coupled with the Reynolds averaged Navier–Stokes (RANS) equations to predict the turbulence-induced interfacial instability of two-phase flow with moving interface. The governing RANS equations for time-dependent, axisymmetric and incompressible two-phase flow are described in both phases and solved separately using the control volume approach on structured cell-centered collocated grids. The transition from one phase to another is performed through a consistent balance of kinematic and dynamic conditions on the interface separating the two phases. The topological changes of the interface are predicted by applying the level set approach. By fitting a number of interfacial markers on the intersection points of the computational grids with the interface, the interfacial stresses and consequently, the interfacial driving forces are easily estimated. Moreover, the normal interface velocity, calculated at the interfacial markers positions, can be extended to the higher dimensional level set function and used for the interface advection process. The performance of linear and non-linear two-equation k–ε turbulence models is investigated in the context of the considered two-phase flow impinging problem, where a turbulent gas jet impinging on a free liquid surface. The numerical results obtained are evaluated through the comparison with the available experimental and analytical data. The nonlinear turbulence model showed superiority in predicting the interface deformation resulting from turbulent normal stresses. However, both linear and nonlinear turbulence models showed a similar behavior in predicting the interface deformation due to turbulent tangential stresses. In general, the developed IMLS numerical method showed a remarkable capability in predicting the dynamics of the considered two-phase immiscible flow problems and therefore it can be applied to quite a number of interface stability problems.
Ashraf Balabel. Numerical modeling of turbulence-induced interfacial instability in two-phase flow with moving interface. Applied Mathematical Modelling 2012, 36, 3593 -3611.
AMA StyleAshraf Balabel. Numerical modeling of turbulence-induced interfacial instability in two-phase flow with moving interface. Applied Mathematical Modelling. 2012; 36 (8):3593-3611.
Chicago/Turabian StyleAshraf Balabel. 2012. "Numerical modeling of turbulence-induced interfacial instability in two-phase flow with moving interface." Applied Mathematical Modelling 36, no. 8: 3593-3611.
The present article focuses on the numerical simulation of two-dimensional (2D) binary droplet collision outcomes in an incompressible continuum gas. The Weber numbers applied to predict the various collision outcomes are within the range of those reported in the previous experiments. The droplet collision dynamics are numerically predicted by solving, separately in both phases, the unsteady 2D Navier–Stokes equations using the control volume approach on non-staggered grids. The complex topological changes of droplet interfaces are described by the level set method (LSM), which simultaneously, provides an efficient and robust way to deal automatically with breaking and merging of interfaces without any numerical constraints. The obtained results demonstrated the essential role played by the surface tension in droplet collision dynamics as a stabilising or destabilising force leading to rebound, coalescence or fragmentation collision outcomes. The mechanism of droplet disintegration at relatively high Weber number and the formation of satellite droplets are also discussed.
Ashraf Balabel. Numerical simulation of two-dimensional binary droplets collision outcomes using the level set method. International Journal of Computational Fluid Dynamics 2012, 26, 1 -21.
AMA StyleAshraf Balabel. Numerical simulation of two-dimensional binary droplets collision outcomes using the level set method. International Journal of Computational Fluid Dynamics. 2012; 26 (1):1-21.
Chicago/Turabian StyleAshraf Balabel. 2012. "Numerical simulation of two-dimensional binary droplets collision outcomes using the level set method." International Journal of Computational Fluid Dynamics 26, no. 1: 1-21.
Ashraf Balabel. Numerical prediction of turbulent thermocapillary convection in superposed fluid layers with a free interface. International Journal of Heat and Fluid Flow 2011, 32, 1226 -1239.
AMA StyleAshraf Balabel. Numerical prediction of turbulent thermocapillary convection in superposed fluid layers with a free interface. International Journal of Heat and Fluid Flow. 2011; 32 (6):1226-1239.
Chicago/Turabian StyleAshraf Balabel. 2011. "Numerical prediction of turbulent thermocapillary convection in superposed fluid layers with a free interface." International Journal of Heat and Fluid Flow 32, no. 6: 1226-1239.
In the present article, the droplet dynamics in turbulent flow is numerically predicted. The modelling is based on an interfacial marker-level set (IMLS) method, coupled with the Reynolds-averaged Navier–Stokes (RANS) equations to predict the dynamics of turbulent two-phase flow. The governing equations for time-dependent, two-dimensional and incompressible two-phase flow are described in both phases and solved separately using a control volume approach on structured cell-centred collocated grids. The topological changes of the interface are predicted by applying the level set approach. The kinematic and dynamic conditions on the interface separating the two phases are satisfied. The numerical method proposed is validated against a well-known computational fluid dynamics problem. Further, the deformation and breakup of a single droplet either suddenly moved in air or exposed to turbulent stream are numerically investigated. In general, the developed numerical method demonstrates remarkable capability in predicting the characteristics of complex turbulent two-phase flows.
Ashraf Balabel. Numerical prediction of droplet dynamics in turbulent flow, using the level set method. International Journal of Computational Fluid Dynamics 2011, 25, 239 -253.
AMA StyleAshraf Balabel. Numerical prediction of droplet dynamics in turbulent flow, using the level set method. International Journal of Computational Fluid Dynamics. 2011; 25 (5):239-253.
Chicago/Turabian StyleAshraf Balabel. 2011. "Numerical prediction of droplet dynamics in turbulent flow, using the level set method." International Journal of Computational Fluid Dynamics 25, no. 5: 239-253.
Ashraf Balabel; Mohamed S. Zaky. Experimental investigation of solar-hydrogen energy system performance. International Journal of Hydrogen Energy 2011, 36, 4653 -4663.
AMA StyleAshraf Balabel, Mohamed S. Zaky. Experimental investigation of solar-hydrogen energy system performance. International Journal of Hydrogen Energy. 2011; 36 (8):4653-4663.
Chicago/Turabian StyleAshraf Balabel; Mohamed S. Zaky. 2011. "Experimental investigation of solar-hydrogen energy system performance." International Journal of Hydrogen Energy 36, no. 8: 4653-4663.
Alkaline water electrolysis is considered to be a basic technique for hydrogen production. Many researchers have investigated the water electrolysis in order to promote electrochemical reaction. The effects of voltage, solution concentration, and space between the pair of electrodes on the amount of hydrogen produced and consequently on the overall electrolysis efficiency are experimentally investigated. The alkaline water electrolysis of different potassium hydroxide aqueous solutions is conducted under atmospheric pressure using stainless steel electrodes. The experimental results showed that, the performance of alkaline water electrolysis unit is highly affected by the voltage input and the gap between the electrodes. Higher rates of produced hydrogen can be obtained at smaller space between the electrodes and also at higher voltage input. Higher system efficiency was also gained at smaller gap distances between the pair of electrodes.
M. Sakr; A-F.M. Mahrous; A. Balabel; K. Ibrahim. EXPERIMENTAL INVESTIGATION INTO HYDROGEN PRODUCTION THROUGH ALKALINE WATER ELECTROLYSIS. ERJ. Engineering Research Journal 2011, 34, 37 -41.
AMA StyleM. Sakr, A-F.M. Mahrous, A. Balabel, K. Ibrahim. EXPERIMENTAL INVESTIGATION INTO HYDROGEN PRODUCTION THROUGH ALKALINE WATER ELECTROLYSIS. ERJ. Engineering Research Journal. 2011; 34 (1):37-41.
Chicago/Turabian StyleM. Sakr; A-F.M. Mahrous; A. Balabel; K. Ibrahim. 2011. "EXPERIMENTAL INVESTIGATION INTO HYDROGEN PRODUCTION THROUGH ALKALINE WATER ELECTROLYSIS." ERJ. Engineering Research Journal 34, no. 1: 37-41.