A coronavirus family is a diverse group of many viruses. Coronavirus disease 19 (COVID-19) spreads when an infected person breathes out droplets and very small particles that contain the virus. These droplets and particles can be breathed in by other people or land on their eyes, noses, or mouths. In this paper, the airflow distribution and the movement of coronavirus particles during normal breathing and sneezing in classrooms have been studied using a CFD model developed in ANSYS® 2022R2. The objective is to find ways to control the spread of the virus that enable us to practice academic activity and deal normally with the pandemic and the spread of the disease. Experiments were done with more than one turbulence model to know which was closest to the experiments as well as to determine the best number of meshes in the classroom. The effect of turbulent dispersion on particles is resolved using a discrete random walk model for the discrete phase and the RANS model for the continuous phase in a coupled Eulerian–Lagrangian method. Furthermore, that is done in two scenarios: the first is to find the best ventilation configuration by investigating the following parameters: the effect of air change per hour, the height of the air inlets and outlets, and the infected student's position. The second is to control the spread of the coronavirus in the classroom in the event of sneezing from an infected student by placing cabins and an air filter with optimal design installed at the top around each student. It was found that optimal ventilation is achieved when fresh air enters from the side walls of the classroom at a distance of 1 m from the floor and the air exits from the ceiling in the form of two rows, and the rate change of air per hour (ACH) is 4, which leads to energy savings. In addition, a novel transparent cabin is designed for the student to sit in while in the classroom, consisting of a high-efficiency particulate air filter (HEPA) that collects any contamination and recirculates it from the top of the cabin back into the classroom with different fan speeds. Through this study, this cabin with a filter was successfully able to prevent any sneeze particles inside from reaching the rest of the students in the classroom.

This paper discusses the effect of burning syngas in a configuration similar to that of the BERL (Burner Engineering Research Laboratory) 300 KW swirl-stabilized combustor which has previously been used with methane as a fuel. Due to the axisymmetric configuration, only 15° from the burner angle is studied with periodic boundary. The model adopts RANS (Reynolds Averaged Navier–Stokes) technique including a realizable k-ε turbulent scheme. The non-premixed combustion model used is based on applying flamelet concept. The study shows that the structure of the flame is affected with changing the burner quarl angle and the inlet air swirl number. The detailed parametric study of this synthetic fuel in the BERL paradigm relates easily to the accumulated experimental and numerical studies available in this configuration and then acquiring add noval value to the present work. The study also shows the presence of different recirculation zones, one of which is central recirculation zone and an external recirculation zone. When increasing quarl angle, the central recirculation zone is shifted outward and the turbulent interaction between the central fuel jet and the recirculation zone induces small vortices between these two flow patterns. On the other hand, the effect of flue gas recirculation and air staging into the burner on the reduction of NOx formation is discussed. The flue gas data show that FGR reduces NOx emissions significantly while having no influence on flame stability, total combustion efficiency, or CO emissions. Changes in fuel composition are also taken into account. The results reveal that when the hydrogen blending in the fuel increases, the temperature rises.

Airborne wind energy (AWE) regards the generation of usable power by airborne devices. In contrast to towered wind turbines, airborne wind energy systems are either flying freely in the air, or are connected by a tether to the ground, like kites or tethered balloons. It turns out that all airborne wind energy systems with significant power output are mechanically connected to the ground in order to exploit the relative velocity between the air mass and the ground; in fact, to be able to harvest wind power, they need to maintain a strong force against this motion. They can be connected to a stationary ground station, or to another moving, but non-flying object, like a land or sea vehicle. Power is generated in form of a traction force, e.g. to a moving vehicle, or in form of electricity. The three major reasons why people are interested in airborne wind energy for electricity production are the following: 1. First, like solar, wind power is one of the few renewable energy resources that is in principle large enough to satisfy all of humanity’s energy needs. 2. Second, in contrast to ground-based wind turbines, airborne wind energy devices might be able to reach higher altitudes, tapping into a large and so far unused wind power resource. The winds in higher altitudes are typically stronger and more consistent than those close to the ground, both on- and off-shore. 3. Third and most important, airborne wind energy systems might need less material investment per unit of usable power than most other renewable energy sources. This high power-to-mass ratio promises to make large scale deployment of the technology possible at comparably low costs. In Egypt a great challenge in producing electricity is to be faced and that may be because of overpopulation and difficult in connecting electricity to remote places so we thought about design and manufacture airborne wind energy in our graduation project to find a solution to overcome that problem. In this work, it is planned to give brief explanation of the procedures starting with an introduction to wind turbine project, the history, review of all airborne wind turbine types and explain the difference between them. Then the system components are to be explained identifying which materials will be used in the system and which generator will produce the electricity. After that attention will be turned into the aerodynamic equations which will benefit us in blades design and knowledge the suitable NACA airfoil which are to be used. At the final stage a suitable design for the balloon of the present system and implementation all the previous stages in manufacturing stage will be discussed.

Municipal Solid Waste (MSW) has emerged as a core issue, which needs to be tackled effectively in developing countries. The burgeoning population indicates increased MSW generation rates indirectly posing challenge to the final disposal. The final disposal is of critical importance as it largely impacts the environment and public health. A number of technologies are available for management and treatment of MSW, but choosing the appropriate one depends on the nature of MSW and local conditions. Selecting the appropriate technology also helps to reduce the greenhouse gas (GHG) emissions, thereby mitigating climate change. The opportunity to reduce GHG emissions is offered by the Clean Development Mechanism (CDM). This paper reports how MSW can be managed effectively through CDM. In total, 350 MSW projects have been registered under CDM across 56 developing countries. In total, 51,292,568 metric tons of CO2e are estimated to be reduced through these 350 projects. China registered the maximum number of projects (102), followed by Brazil and Mexico registering 45 and 28 projects, respectively. Overall, 175 projects from China, Brazil, and Mexico account for about 51.63% of the total estimated emissions reductions. Asian region reported the highest number of projects of 191 followed by South American region. There were 16 methodologies that have been used as stand-alone as well as in combination for management of MSW through CDM and cover several areas through which the potential of MSW can be trapped. China and India used the maximum methodologies, followed by Brazil. Registering for CDM offers financial benefits as well as technology transfer and ultimately sustainable development. Source reduction and technology development to suit local needs are the areas where developing countries can focus. An integrated system for solid waste management is perfectly suitable for developing countries. The common practice for household refuse disposal in rural areas is to dump solid wastes openly in backyard gardens or in an open space. Such indiscriminate disposal is an environmental hazard and can threaten human health and safety. Solid waste that is improperly disposed of can result in a number of problems. It can create a breeding ground for pathogenic microorganisms and vectors of disease and cause a public nuisance due to unsightliness and bad smell. It can cause contamination of surrounding soil, groundwater, and surface water, and it can also create fire hazards, physical hazards and have poisoning effects (from pesticides and insecticides). However, these problems can be avoided by using appropriate management techniques [1]. For all waste management issues, your role should be to engage community members and families in awareness of the solid waste problems in their area and try to change their behavior. In doing so, it should be possible to have a clean, attractive, and sustainable environment. In this study session, you will learn about the different types of solid waste and their common sources. You will also learn about the stages in solid waste management and appropriate disposal methods. Proper management of solid waste will help your community prevent communicable diseases and safeguard the environment in a sustainable manner. Americans alone are responsible for producing a whopping 277 million tons of waste (annually). Since this number is far more than any other nation in the world, the US government and Environmental Associations have devised numerous methods to deal with this burning issue. But what exactly is Waste Management? In the simplest terms, it can be defined as the collection, transportation, and disposal of garbage, sewage, and other waste products. The process of waste management involves treating solid and liquid waste. During the treatment, it also offers a variety of solutions for recycling items that are not categorized as trash. The entire idea thus boils down to reusing garbage as a valuable resource and given our current environmental climate, this process is extremely vital for all households and businesses. Waste management or waste disposal is all the activities and actions required to manage waste from its inception to its final disposal. This includes among other things, collection, transport, treatment, and disposal of waste together with monitoring and regulation. It also encompasses the legal and regulatory framework that relates to waste management encompassing guidance on recycling, etc. You will find there are eight major groups of waste management methods, each of them divided into numerous categories. Those groups include source reduction and reuse, animal feeding, recycling, composting, fermentation, landfills, incineration, and land application.

This paper is devoted to numerically investigate the influence of location and number of ventilation and air conditioning supply and extracts openings on air flow properties. The work focuses on air flow and thermal behaviour. Six different cases for change in location supply-extract air are studied to reveal the impact of changing the location on the overall comfort levels and indoor air quality for people. The performance of the air conditioning system is characterized by airflow patterns, temperature. This is the main target during the present thesis work. The study is carried out using computational fluid dynamics (CFD) simulation techniques as embedded in the commercially available CFD code (ANSYS 16). The CFD modelling techniques solved the continuity, momentum and energy conservation equations in addition to RNG k – ε model equations for turbulence closure.

Cooling Towers are one of the main components utilized in numerous major processes applications; any decrease in the cooling tower performance highly affects the main process. One of the major causes of deficiency is the recirculation of hot humid air from the cooling tower outlet back into the cooling tower air intake. As recirculation occurs, the average entering wet bulb temperature at the intake of cooling tower increases which results in efficiency loss at the cooling towers and accordingly the associated process equipment up to the limit that it might causes malfunction of the equipment. The present work aimed to study the aspects leading to cooling tower recirculation using Computational Fluid Dynamics CFD to determine recommendations and considerations for cooling towers layout to minimize recirculation and ensure stable and efficient operation. The current work focuses on predicting the air flow patterns around cooling towers via investigation of air flow thermal properties and moisture content. This current works utilized computational fluid dynamics (CFD) to investigate the effect of wind direction, wind velocity and cooling towers roof arrangement on cooling towers recirculation. The present investigation represents a parametric study on recirculation at different winds speeds, direction; fans exit velocities, architectural enclosure louvers location, and cooling tower position above ground.

Smoke management system in all buildings received great interest as a way to decrease fatalities during fires as it prevents spread of fire and provides a safe escape route for occupants. This research provides a numerical study for smoke control in the cinema. This research investigates the effects of natural ventilation and mechanical ventilation on basic design parameters such as smoke layer height, concentration of carbon monoxide (CO), temperature, and visibility at the entry and the exit doors which are the evacuation routes in the cinema. Fire Dynamic Simulator (FDS) was used in simulating seven design cases in a cinema hall that has dimensions of 13.8 m length, 13.5 m width and 6.5 m height. The FDS results were validated and the numerical results of FDS are shown to be in good agreement with the results of the experiment that is presented by Rinee et al. The results show that not using natural ventilation by closing the doors is very dangerous as the tenable conditions are worsened and exceed critical limit and the entry and the exit doors are exposed to high danger so natural ventilation is important. Also the results indicated that the mechanical ventilation is very important as increasing the air change per hour enhances the tenable conditions as it decreases the temperature and the concentration of CO and it makes them in the accepted range, also it enhances the visibility leading to easier and safe escape for the occupants.

Predictions of furnaces flow properties such as flow pattern, flame structure, heat transfer and pollutant emission rates furnish the bases for design computations foe efficient furnaces. The governing equations are solved through the use of SIMPLEC algorithm with finite differences or finite volume techniques. As Most of the actions occur in the combustion zone, the present work focuses on investigating the application of Computational Fluid Dynamics CFD to predict the flow and thermal patterns in the burner quarl. Efficient fossil energy utilization in power generation together with low pollution in conventional thermal power plants is of growing interest internationally. Efficient energy use is favorable for better productivity product quality, costs, and quality of human life but the energy use adversely impacts our environment. The ability of numerical computations to predict the boiler furnace thermal behavior is an ultimate goal. The heat transfer to furnace walls through thermal radiation is reviewed briefly to demonstrate the present capabilities applied to burner quarls.

The recent advances in numerical methods and the vast development of computers had directed the designers to better development and modifications to airflow pattern and heat transfer in complex geometries such as combustion chambers, aluminum reductions cells and air conditioned operating theatres. The Present work fosters mathematical modeling techniques to primarily predict what happens in three-dimensional complex geometries and presents a summary of its status quo. Applications include, among others, combustion chambers, aero engines in terms of flow regimes and interactions .It also includes predictions of flow and heat transfer in Aluminum reduction pots where the pot is full with the molten metal and electrolyte in the anodes- cathode void. Magnetic field and forces would result in molten metal movement, stirring and consequently possible re-oxidation of aluminum at anode surfaces causing low productivity. The flow in air-conditioned operating theatres is also addressed in this paper. The present work is generally devoted to demonstrate the effect of design and operational parameters on performance of such systems. The governing equations of mass, momentum, species and energy are commonly expressed in a general finite difference form to be solved with the aid of SIMPLE Algorithm. The results are obtained in this work with the aid of the three-dimensional program; applied to axe symmetrical and three-dimensional complex geometries. The present numerical grid comprises, typically, total of 14 million grid node covering the volume in the X, R or Y and Z coordinates directions. The numerical residual in the governing equations typically less than 0.001 %. The obtained results include velocity vectors, turbulence intensities, temperatures and wall heat fluxes. Flow regimes and heat transfer were found to be strongly dependent on turbulent shear, mixing, blockages, wall conditions and inlet conditions. Examples of large industrial furnaces, reduction cells and operating theatres are shown and are in good agreement with available measurements in the open literature .One may conclude that flow patterns, turbulence and heat transfer in complex geometries are strongly affected by the inlet and boundary conditions; both micro and macro mixing levels are influential. The present modeling capabilities can adequately predict the local flow pattern and turbulence kinetic energy levels in Complex geometries

Many inserts are used for increasing the performance of double pipe heat exchangers that are mentioned in the literature review. Most of them work as swirl generators helping in increasing the turbulence of flow. This causes better mixing for flow and consequently increases the heat transfer rate and pressure drop. The goal of this thesis is to study the effect of using twisted tape, with different twist ratios, on the heat transfer rate and the friction factor of the inner tube of a double pipe heat exchanger. The aim is to decide on the optimum twist ratio resulting in the best heat transfer rate. It is found that the efficiency of heat transfer of double pipe heat exchangers can be improved by using twisted tape insert inside the inner tube. This causes better mixing for the flow and consequently increases the heat transfer and pressure drop. The results show that, using twisted tape increases the heat transfer rate and friction factor when compared with plain tube. As the twist ratio decreases, the heat transfer rate increases, but also leads to increasing the friction factor. The twisted tape with ratio H=1.7 gives the highest Nu which is 1.8 times that of plain tube at Re=18000 with the optimum thermal performance factor (PEC).

This paper studies the effect of exhaust grilles location on air flow regimes. The three presented cases study the air velocity profile in three different exhaust grille locations. The first design has two exhaust grilles along the same wall, while the second design option has the exhaust grilles on the opposite walls. The third design option combines the first two options, with four grilles in total, two on a common wall, and two others on the opposite wall. The study is performed by means of Computational Fluid Dynamics (CFD) using ANSYS 17.2. The objectives of this research were to determine the best exhaust grilles location which would create laminar flow and result in fewer vortices that might prevent generated particulates to settle down or migrate around the laboratory.

For cases when it is difficult to introduce sufficient amounts of natural ventilation air to air-cooled chillers, mechanical ventilation is required. A typical example is mechanical/chiller rooms. Due to the confined space, part of the Chillers exhaust air is expected to be circulated back as part of the total intake air, eventually decreasing the coefficient of performance (COP) of the chillers. The objective of this study is to simulate the airflow distribution around chillers in such mechanical rooms and to analyse the impact of room height, locations of the intake and exhaust louvers, number of chillers, and intake air velocity on the COP of chillers. This is achieved by developing a computational fluid dynamics (CFD) model in ANSYS® 19.0. The study shows that the intake louver air velocity is the most influential parameter that can significantly affect the performance of the chiller, and the lower this velocity is, the higher the chiller’s intake air temperature. The best configuration for the air louvers is to introduce the air from two side inlets and to locate the exhaust louver at the top of the room. Finally, the room’s clear height also affects the recirculation process, but it has a lower impact when compared to other parameters.

This paper reviews the previous attempts to evaluate the Indoor Air Quality (IAQ), investigates previously proposed IAQ factors and analyses the evaluation methods of these factors. The present work introduces, also, a new hypothesis of the optimum HVAC airside system design of the surgical operating theatres to achieve the comfort and hygiene levels. The present work is devoted to propose and formulate a new scale capable of adequately evaluating the airflow pattern in the surgical operating theatres. The proposed new scale is proposed to cover the local and overall air quality evaluations. A new Neuro fuzzy technique was applied to derive measures for indoor air quality indices. Indoor Air Quality (IAQ) is more critical in healthcare facilities due to the dangerous microbial and chemical agents present and the increased susceptibility of the patients. Hospitals and other healthcare facilities are complex environments that require ventilation for comfort and to control hazardous emissions. Surgical operating theatre is the most important and complex zone in the hospital, and requires more careful control of the aseptic conditions of the environment. Most of the previous researches aiming at evaluating the IAQ were based on the evaluation of the air distribution depending on the residence and leaving age of the air supplied to the enclosure. Other attempts were also reported to indicate the effectiveness of contaminant removal by the entire airflow pattern as an indication to the IAQ. This paper recommends some designs of the supply air outlets to provide the vertically downward airflow as a practical solution. The near ceiling and near floor extract ports are to be used instead of the hypothetical complete floor extract as a practical solution.

Today we spend more and more time indoors, where we expect a level of thermal comfort, so providing an acceptable level of thermal comfort in a classroom is important for our health and to improve student’s performance when studying in order to get the most scientific benefits. The thesis is keen to numerically investigate influence of changing the type of air outlet on the distribution of air and the thermal comfort for the occupants inside the teaching space and choosing the best design of air conditioning inside an educational classroom in Institute of Aviation Engineering and Technology, Cairo, Egypt. The classroom is located on the second floor of the building of architecture, Hall 3201. An experimental investigation on the same classroom was accomplished which aims to validate the used CFD code ANSYS 19 (FLUENT), and a Good the agreement is found among both predictions. These investigations included the measurements of relative humidity, and temperature, which were done using (Elcometer 319 Dewmeter gauge); the average error between numerical and experimental data of relative humidity is 3 %, and1.8 % for temperature results. The domain assembly case was finally discretized into 4,444,200 averaged tetrahedral elements. In case of using a four-way square diffuser, results illustrate that The appropriate design in case of using a 4- way square diffuser as an air outlet type is by discharging air with an angle of (30°) and a velocity of 4 m/s, which attains stages of thermal comfort, while discharging air with a velocity of 5m/s has no agreement with the conditions of thermal comfort due to the value of air velocity at occupant level which is more than 0.25 m/s.

A smart city provides a high quality of life to its inhabitants through optimal management of its resources. By definition a smart city is equipped with smart infrastructure that provides improved quality of life with sustainable environment through smart built solutions. In their operation, smart cities would entail a highly reliable, energy efficient, and high-quality power; smart grid becomes obviously imperative. Energy management is demanded within such urban centers due to the complexity of the energy systems and their important role. Mathematical simulation and predictions are the major tools commonly used to assess the technological and policy impacts of smart solutions. Distributed energy systems can be represented in the form of microgrids and combined heat and power. As cities are developed to become smarter, energy form and access to it become consequently even more integral part of modern living forms. Newer energy systems must also be transformed to become increasingly more reliable and resilient. Solar cells and wind energy technologies remain the best candidates in terms of new major energy sources in smart cities even with their dependence on natural processes. These energy sources should remain the future backbone of smart energy systems. In fact, solar panels for practical applications in buildings have made such substantial jumps since their inception a few years ago that prices have remarkably dropped worldwide. However, the transition to a fuller solar-wind energy economy arrives with a drastic set of challenges, including inherent inefficiencies in current energy battery storage capabilities. This is particularly apparent in the transport sector, which has the most trouble when anticipating its energy transition. Considering the unavoidable intermittent nature of wind and solar energy supply within a day, week, month, traditional centralized power production, and distribution are questionable. If unchanged, it will be more difficult to maintain a robust energy provision. The integration of wind and solar into practical energy system in cities demands significant investment.

To reach the required thermal comfort in addition to the safety environment and conditions for the travelers. The present numerical investigation was carried out using ANSYS FLUENT CFD (Computational Fluid Dynamics) package. Full three dimensional governing equations of mass, three momentum, energy and species concentrations were solved. The turbulence characteristics of the flow were represented through the application of the RNG k-epsilon model equations for turbulence model. Mesh sizes used in the present study were about 7,000,000 mesh volumes and 1,000 iterations for each case. CFD simulations are incorporated to indicate the effects of attaining thermal comfort through selection of the location of air inlets at the ceiling and variation the locations of air outlets inside the metro cabin to achieve the best the thermal comfort conditions. The main objective of the research conducted is to examine the airflow regimes and thermal comfort in metro cabin using computational fluid dynamics (CFD) software. The designed air velocities were in the range from 0 to 0.12 m/s(24 fpm) and this provides thermal comfort; the range of temperature was from 19 to24oC(66 to75 oF) with rise in the temperature in between the passenger’s bodies due to crowdness.

In this paper, thermal-hydraulic characteristics and performance of turbulent flow of various Nanofluids in a various conical double pipe heat exchanger (fourteen different combinations of flow direction and conical tubes geometries) are numerically investigated. Intensification of heat transfer rate with geometrical modification of double-pipe heat exchanger by altering the traditional straight cylindrical form of the tubes into conical tubes as a passive heat transfer enhancement technique with a combination with various Nanofluids as another passive technique of heat transfer enhancement is numerically studied. Effects of the combination between various straight/conical tube arrangements with different flow directions (parallel/counter) and various Nanofluids (DW/SiO2, DW/Al2O3, and DW/GNP-SDBS) are studied and compared with water as a base-fluid within Reynolds number range from 7000 to 35,000. Validation and grid independence study were performed. Structured, non-uniform grid generation is applied. Continuity, momentum, and energy equations were treated by means of a finite volume method (FVM) using the SIMPLE pressure-velocity coupling algorithm with the k–ε turbulence model and enhanced wall function as a wall treatment using Ansys-Fluent package. Heat transfer in terms of Nusselt number (Nu), pressure drop in terms of friction factor (f), and overall thermal efficiency in terms of performance evaluation criteria (PEC) have been carried out as the main parameters of the study. In addition, for deep-studying of the thermal/flow structure, contours of velocity, temperature, and turbulent kinetic energy (TKE) are presented. The results reveal that the combination between the straight/conical shapes and Nanofluids have noticeable effects upon the Nusselt number (Nu), the friction factor (ƒ) and thermal evaluation criteria (PEC) compared with the traditional straight tubes or without Nanofluids. Case (g) provides the highest values of heat transfer rate in the form of Nusselt number (Nu), and the highest values of pressure drop in the form of friction factor (f) is presented by Case (j) and Case (m) compared with the rest of studied cases. For case (g), the average percentages of enhancement of Nu compared with the traditional straight tube with parallel flow are 55.2%, 48.1%, 48.8%, and 28.8% for DW, DW/Al2O3, DW/SiO2, and DW/GNP-SDBS. Furthermore, for case (g), the average values of PEC are 1.13, 1.065, 1.06, and 0.87 for DW, DW/SiO2, DW/Al2O3, and DW/GNP-SDBS. Moreover, the maximum values of PEC are 1.209, 1.138, 1.133, and 0.92 for DW, DW/SiO2, DW/Al2O3, and DW/GNP-SDBS. It can be concluded that the conical double pipe heat exchangers are considered as a promising technique in heat transfer enhancement (percentage of augmentation in Nu is 55.2 % compared with the traditional straight double pipe heat exchanger) with taking in consideration energy saving (PEC ≥ 1).

Contaminant transport in the aircraft cabin became one of the most vital issues that should be concerned; because there are over 4.6 billion passengers choose travelling by aircrafts, as they are safe, comfortable, and fast. In addition, aircrafts manufacturers aim to produce large aircrafts that are able to contain the highest number of passengers. Airborne diseases, for example, SARS and Influenza are considered the most fatal diseases, which can transport in the cabin rapidly, due to the large number of particles or droplets in one cough or sneeze as well as the velocity of these particles, as a consequence these characteristics, airborne pathogens such as cough and sneeze can spread and reach great number of passengers at one time. This study shows the result of simulation of cough droplets that produced from an infected moving passenger using computational fluid dynamics simulation (CFD) and dynamics mesh and discrete phase models in ANSYS FLUENT program, also it reveals the effects of these produced droplets on the other passengers inside the cabin. The results reveals that, cough droplet that produced during the movement of the passenger are extremely detrimental, as it could spread to a distance more than 4 meters along the cabin, moreover, it affected too many passengers in the cabin.

Heat exchanger is a device used to transfer heat from one medium to other. Baffles are used to enhance heat transfer performance in shell and tube heat exchanger. The most common type of baffles is segmental baffles because of their strong geometry construction and easy maintenance. In the present study, 3-D numerical model is used to investigate the effects of changing number of baffle, mass flow rate and orientation angle of the baffle on the thermal characteristics of a shell and tube heat exchanger. The shell side heat transfer coefficient, pressure drop and the outlet temperature are resolved using commercial CFD package, ANSYS Fluent Version 19. The shell and tube heat exchanger used in this study had a shell of (600mm length, 90mm diameter) and one pass with 7 tubes of (20mm diameter) with 36% baffle cut. The investigated cases are carried out with four numbers of baffles (6, 8, 10, and 12 baffles) and three baffles orientation angles of 45⁰, 90⁰, and 180⁰ at different mass flow rates. The validation is done by comparing the numerical results using realizable k-epsilon turbulence model with Bell-Delaware analytical method results and the predictions of Ozden et al. The results reveal to that, the important role of increasing the number of baffles from 6 to 12 in enhancing the heat transfer and increasing the outlet fluid temperature, but on the other hand increasing the pressure drop. Also It is noticed that, at the same number of baffles, case of 180⁰ orientation angle is better than of 45⁰ one in heat transfer rate and outlet temperature, moreover it is very close to case of 90⁰ orientation angle in results

A smart city is an energy efficient and sustainable urban center that supplies a high-quality life for its users and dwellers. This is achieved through optimum management of its available and affordable resources. A smart city is defined as a city equipped with intelligent services and infrastructure that assure an improved quality of life with sustainable smart built environment solutions. Smart cities aim to attain a reliable, energy efficient, and high-quality power and thus smart grid becomes imperative. Energy management in smart cities would be one of the most demanding issues due to the complexity of the energy systems and their vital role. Significant attention and effort need to be focused directed and dedicated to efficiently solve this problem. Mathematical modeling and simulation are among the major tools commonly utilized to assess the technological and policy impacts of smart solutions, as well as to plan the best directions of shifting from current cities to smarter ones. Distributed energy systems, likely in the form of microgrids and combined heat and power—small, local energy system comprised of single or multiple entities that generate electric and thermal, energy and operate autonomously from or are integrated into the power grid. Energy and access to smart cities will become an even more integral part of modern living in cities. In other words, on top of addressing an unsustainable demand for energy, new energy systems must also be increasingly more reliable and resilient. Broad agreement among energy experts is that solar and wind remain to be the best candidates in terms of new major energy sources in smart cities, and should be considered as the backbone of future energy systems. Solar panels have made such substantial leaps since their inception a few years ago that prices have dropped drastically with the expansion of their utilization in the United States, Europe, and Middle East. However, the transition to hybrid solar-wind energy systems comes with its own set of challenges, limitations including current inefficiencies in present energy storage capabilities. This is quite apparent in the transportation sector, which exhibits the most trouble when anticipating its energy transition. Given the intermittent nature of wind and solar energy, it is also necessary to consider the present focus on traditional centralized power production and distribution, which if neither unchanged, nor developed will become harder to maintain. Evidently, hybrid wind and solar integration into our energy system implies significant investment in research, as well as improvement of equipment and deployment.