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Öğe A Review of Solar Panel Cooling Methods and Efficiencies(Abylkas Saginov Karaganda Technical University, 2025) Aljumaili, Ahmed; Alaiwi, Yaser; Al-Khafaji, ZainabPhotovoltaics is one of the most widely employed clean energy sources on earth. However, when the temperature of the PV cell rises, its electrical power decreases, which makes it essential to find ways to develop the module's efficiency in high-temperature situations. One of the techniques used to raise efficiency and performance is cooling. Researchers have used a variety of ways to cool solar PV panels, including active and passive methods. Researchers used a forced air stream, PCM, a heat exchanger, water, and many other methods to make a solar PV thermal system work better. The principal purpose of this chapter is to look at the significant information the researchers found in their research about how to improve the efficiency and performance of PV cells, how to cool them, and other reasons that affect the output of solar cells.Öğe Advancements in Concentrated Solar Power: A Review of Heat Transfer and Parabolic Trough Technologies(Abylkas Saginov Karaganda Technical University, 2025) Al-Aloosi, Waleed; Alaiwi, Yaser; Al-Khafaji, ZainabThis review examines the advancements in concentrated solar power (CSP) technologies, focusing on their potential to meet energy demands sustainably while mitigating global warming. CSP systems, which harness solar energy through mirrors and lenses to generate high-temperature heat, offer a reliable alternative to fossil fuels. Key CSP technologies include Linear Fresnel Reflectors, Parabolic Dishes, Solar Towers, and Parabolic Trough Collectors (PTCs). Each system is assessed for its design, efficiency, and suitability in regions with high direct solar irradiance. Among these, PTCs are highlighted for their cost-effectiveness and thermal efficiency, with applications reaching temperatures up to 550°C, making them suitable for both small and large-scale implementations. The review also explores various heat transfer enhancement techniques, categorized into active, passive, and compound methods. Passive techniques, such as inserts, surface modifications, and nanofluids, are examined for their ability to increase heat transfer efficiency without external energy sources. Active methods like pumps, fans, and compound approaches are discussed for maximizing thermal performance. Advances in receiver design, including twisted tapes, wire coils, fins, and porous materials, are evaluated for their impact on heat transfer rates, thermal losses, and overall system efficiency. Additionally, the potential of nanofluids to improve thermal conductivity is explored. This comprehensive review underscores the importance of optimizing CSP systems to maximize efficiency, offering insights into innovations that could further enhance the adoption of solar thermal energy worldwide.Öğe Corrosion reduction in steam turbine blades using nano-composite coating(Elsevier B.V., 2023) Sattar, Sabaa; Alaiwi, Yaser; Radhi, Nabaa Sattar; Al-Khafaji, Zainab; Al-Hashimi, Osamah; Alzahrani, Hassan; Yaseen, Zaher MundherThe current study aims to reduce the hot corrosion issues in steam turbines for Al-Mussaib thermal power stations. To gain the aim of the study, many experimental tests were conducted by taking a sample from an existing broken steam turbine blade to identify the alloy composition and preparing samples with exact composition by powder metallurgy method, then using the electro-deposition method to coat the prepared samples by three different coating composite materials consists of TiO2 in different ratios (5, 10 and 15) g/l and 5 g/l SiO2 added to Watt's solution. To verify the efficiency of coating, several tests were conducted (surface roughness, hardness, wear, and oxidation test). The obtained results indicated that increasing the Ni-5%SiO2-TiO2 (5, 10 and 15) g/l caused an increase in the coating thickness, which is compatible with increasing the surface roughness. Also, the sample hardness increased after coating, which returned to increasing TiO2 amount (5, 10 and 15) g/l. However, wear resistance for the samples after coating by selected coating composite and 10 g/l TiO2 amount records the highest reduction in the wear of the sample.Öğe Exploration Of Key Approaches to Enhance Evacuated Tube Solar Collector Efficiency(Penerbit Akademia Baru, 2024) Al-Abayechi, Yasir; Alaiwi, Yaser; Al-Khafaji, ZainabThis research is carried out to investigate and examine the critical benefits and significant contributions of integrating nanoparticles into the ETSC system to enhance the thermal efficiency, thermal performance, temperature out, and energy storage of the ETSC. The Simcenter STAR-CCM+ 2022.1 software package implemented numerical analysis and thermal simulations. Further, a comparative analysis is conducted on two case studies to validate the critical role and contributions of employing the aluminum oxide nanomaterial in the solar collector system to enhance its thermal efficiency and improve its thermal performance and heat transfer, including (1) conventional ETSC and (2) ETSC with Al2O3. According to the numerical analysis and comparative study findings, the results of this research revealed that employing and adding the aluminum oxide nanomaterial into the ETSC system had contributed to several beneficial impacts and significant advantages. In addition, using Al2O3 achieved enhancements in the thermal efficiency, increases in the outlet collector’s temperature, improvements in the rate of heat flux of the pipes, the tube inside the collector, heat transfer of the hot water storage tank, and a rise in the temperature gradient the hot water temperature increased from (between 44.3 and 74.8 ºC) to (between 49.6-80.3 ºC). Besides, the velocity of the water flow inside the solar collector in the second case in which the aluminum oxide nanoparticles are used was higher due to the absorption of further solar radiation and thermal energy, which resulted in a considerable increase in the kinetic energy of water molecules from 0.01 to 0.07 m/s. Also, it was found that the velocity directions and profile were slightly more turbulent in the second case than the conventional solar collector due to more thermal energy absorbed and stored in the ETSC from solar radiation. © 2024, Penerbit Akademia Baru. All rights reserved.Öğe INVESTIGATING BACK SURFACE COOLING SYSTEM USING PHASE CHANGE MATERIALS AND HEATSINK ON PHOTOVOLTAIC PERFORMANCE(Mustansiriyah University College of Engineering, 2024) Aljumaili, Ahmed; Alaiwi, Yaser; Al-Khafaji, ZainabThis research aims to improve thermal performance and compare the performance of two common crystalline PV panel types (Mono and poly). Modules with a back-cooling system were designed and numerically analyzed with SolidWorks and ANSYS-Fluent-2021-R2 for the simulation under Baghdad weather at noon. The cooling system used consists of a phase-change material, paraffin wax (RT55), with a thickness of 5 cm and a heatsink with 33 fins with heights of 10, 20, and 30 mm and thicknesses of 2, 4, and 6 mm. to select the best height of the wax 1, 3, 5, 10, 20 cm examined. The result showed that for polycrystals, the panel temperature was reduced by 8.4°C using PCM and 11.9°C using PCM-fins. Also, output power was enhanced to 200.6 W by 10.2 W, and efficiency improved by 5%. Similarly, using PCM and PCM-fins lowered the temperature of the monocrystalline by 8.3 and 12.5°C, respectively. Therefore, the output power is enhanced to 202.4 W by 10.7 W and improves the electrical efficiency by 5.2%. The results of the study showed that mono had better performance than poly. This result is acceptable and is in good agreement with previous studies. © 2024, Mustansiriyah University College of Engineering. All rights reserved.Öğe Investigation of Heat Transfer and Swirl Flow Between Concentric Cylinders(Hashemite University, 2025) Jasim, Mohanad Abdulkhudhur; Alaiwi, Yaser; Al-Khafaji, ZainabSwirl flows, especially in decaying forms, have shown promise in enhancing thermal performance with minimal mechanical complexity, providing a practical alternative to traditional forced convection methods in annular geometries. The swirling flows are created by introducing tangential air inflow, which promotes mixing and disrupts thermal boundary layers, thereby increasing heat transfer. This approach is valuable in applications where efficient thermal management is critical, such as in heat exchangers, reactors, and rotating machinery. This study highlights the potential effectiveness of swirling decaying flows in enhancing heat transfer, as initially proposed by Talbot. Local Nusselt numbers were experimentally measured in an annular space between concentric cylinders under a constant heat flux boundary condition. Swirling air motion was generated by tangential inlet slots, allowing air to enter with varying slot numbers and tangency angles. The resulting flow field within the annulus maintained a Reynolds number below 2000, aligning with the study's focus on low-Reynolds, laminar flow conditions for examining the impact of swirl flow on heat transfer between concentric cylinders. Careful consideration was given to keeping track of errors from their collection of sources and their propagation in the results. In heat transfer enhancement, swirling flow showed real promise; augmentation of up to 24 % could be achieved, while in power consumption, swirling flow was considerably more demanding than the fully developed non-working laminar flow. Even with the acceptable accuracy of the experimental measurements, the data reduction yielded substantial errors - up to 300 % of the calculated value - thereby undermining the results and the assumptions.Öğe Investigation of the Effect of Adding Nitrogen on the Torque Generated by a Four-Cylinder Engine(Semarak Ilmu Publishing, 2025) Jasim, Mustafa Raheem; Alaiwi, Yaser; Al-Khafaji, ZainabThe engine's power stroke involves injecting LN2 into the cylinder at the top dead centre, allowing nitrogen and air gas to escape. This process, without combustion, overcomes engine friction losses, enabling intake, compression, and output power. Previous studies have focused on improving diesel engine efficiency by adding materials like hydrogen, NO2, clean gasoline, ammonia, LN2, NO, and NOX and altering engine design and spark plugs. This study explores the potential benefits of liquid nitrogen-fuelled automobile engines despite their past inefficiency and similarity to compressed-air engines due to energy waste. The study underscores the potential of nitrogen gas addition in improving the cleanliness and efficiency of diesel engines, paving the way for further research and advancements. Uses CFD simulations to analyze the impact of nitrogen gas concentration on combustion effectiveness, emissions, and performance metrics of a compression-ignition diesel engine, explicitly focusing on nitrogen oxide and particulate matter emissions and their influence on mixture flow velocity. The addition of nitrogen gas significantly impacts combustion dynamics, altering temperature and pressure patterns. The mass flow rate and velocity are positively correlated, and the crankshaft deforms more rapidly with engine rotational speed. Nitrogen gas concentrations affect deformation and pressure, with higher values observed at 1800 RPM and 2200 RPM. The combustion process can be enhanced by adding hydrogen concentrations, changing engine shapes and designs, or using different fuel types. Nitrogen gas concentrations inversely relate to temperature, with higher concentrations causing lower temperatures, which is consistent with nitrogen gas's primary role in reducing engine temperature. Nitrogen gas concentration is linked to pressure gradients.Öğe Numerical investigation of nanofluid-based flow behavior and convective heat transfer using helical screw(Penerbit Akademia Baru, 2024) Khlewee, Abdulqader Sala; Alaiwi, Yaser; Jasim, Talib Abdulameer; Mahdi, Mohammed Alamin Talib; Hussain, Abdullah Jabar; Al-Khafaji, ZainabA multitude of industrial and residential customers have utilized heat transfer devices for heat conversion and recovery. For the last fifty years, engineers have diligently endeavored to refine a heat exchanger design that reduces energy use without compromising efficiency. Most techniques for enhancing heat transfer operate by either augmenting the effective heat transfer surface area or inducing turbulence, hence reducing thermal resistance. This work utilized CFD to model Al2O3 and CuO nanoparticles inside the adsorber tube of a parabolic solar collector with N=1 and N=2 turbulators at Re of 20000, 60000, and 100000, respectively, with a turbulence intensity of 5%. The turbulence intensity was determined to be 5% of the total energy of the particles. The inclusion of nanoparticles in the base fluid enhances heat conduction. Consequently, nanofluids are viable options for alternate heat transmission mechanisms. Torsional turbulator models with N=2 have a higher output temperature (Temp) than those with N=1 due to the elevated practical heat level of the N=2 models. The intake temp is elevated from 35 to 46 degrees Celsius due to the existence of CuO nanoparticles in the adjacent turbulator adsorber tubes. The Reynolds number (Re) consistently increases the Nusselt number (Nu). Furthermore, the Nu indicates a higher quantity of CuO nanoparticle models compared to Al2O3 nanoparticle models. Furthermore, CuO nanoparticles exhibit superior efficacy compared to Al2O3 in pressure reduction. In comparison to the N=2 dual-turbulator mode, the N=1 single-turbulator mode exhibits a 34% increase in conflict. Pressure loss coefficients are higher for devices including two turbulators. Across a broad spectrum of Re, the thermal PEC for N=2 models exceeded that of N=1 models by 12 percentage points. CuO nanofluid receivers have better efficacy compared to Al2O3 receivers in the conversion of solar energy into thermal energy. The two-turbulator model, operating at a Re of 100000 and using CuO nanoparticles, attains optimal thermal efficiency. The factor of friction decreases with increasing Re, with Water N=1 showing higher frictional losses than Water N=2, indicating greater turbulence and resistance.Öğe Numerical simulation for effect of composite coating (TIO2+SIO2) thickness on steam turbine blades thermal and stress distribution(Editura Politechnica, 2023) Sattar, Sabaa; Alaiwi, Yaser; Radhi, Nabaa Sattar; Al-Khafaji, ZainabThe steam turbine is the most effective and straightforward method of converting thermal energy into mechanical power. As steam expands, its velocity increases, exerting strong stresses on the turbine blades. The linear motion of the incoming steam with high temp and pressure is converted to rotation of the turbine shaft by the turbine blades. The most important issue in power plants might be corrosion in the turbine blades. Corrosion might cause turbine blade masses to be out of balance, which can cause major vibration issues. The ANSYS software program did a numerical analysis to investigate the impact of coating thickness for the selected coating materials (Ti, TiO2, and SiO2) on the steam turbine. The numerical analysis was done using six coating groups; three of them consist of single materials (Ti, TiO2, and SiO2), and the other three consist of hybrid coating (Ti+ TiO2, Ti+ SiO2, and Ti+TiO2+SiO2) and each group has three coating thickness (0.01, 0.02 and 0.04) μm. Numerical analysis results indicated that the total heat flux and the temp increased after applying the coating. In contrast, total deformation for all selected groups was decreased after applying a coating for all of them; the change in the coating thickness from (0.01 to 0.04) μm has no effective changes on the samples after coating. Using (Ti and TiO2) show a significant increase in max principal stress compared to the uncoated sample. The application of Ti shows the impact of coating thickness on max principal stress, where a change in the coating thickness from 0.01 to 0.04 μm leads to a reduction in the max principal stress value from 1421.9 to 1211.4 MPa.Öğe Performance Evaluation of Multiple Wind Turbines Integrated with Buildings(Semarak Ilmu Publishing, 2025) Alaiwi, Yaser; Al-Khafaji, Zainab; Jasim, Talib Abdulameer; Mahdi, Mohammed Alamin Talib; Falah, Mayadah; Al-Kafaji, Mustafa Raad HasanWind power became easy to access, clean, safe and cost-competitive among all renewable energy sources. It became one of the fastest-growing renewable energy resources in electricity generation. The wind power Horizontal axis wind turbine (HAWT) is proportional to the swept area. A multi-rotor can increase the area of the wind turbine in an array or a large diameter of a single rotor. Rotor sizes are continuously expanding with mature technology. In this research, a study was carried out to describe the flow simulation of a two-rotor, three-blade, ducted horizontal-axis wind turbine to evaluate its performance. The coefficient of performance increased by converging channels with convergence angles of 20° and 12°, respectively, because convergent ducts cause an increase in wind speed. DMRWT simulation and numerical analysis by MATLAB and ANSYS FLUENT. Both approaches presented good results.Öğe Reducing oil pipes corrosion by (ZN-NI) alloy coating on low carbon steel substrate by sustainable process(Taylor's University, 2023) Radhi, Nabaa Sattar; Al-Khafaji, Zainab; Mareai, Basim M.; Radhi, Sabaa; Alsaegh, Ayam M.The problem of corrosion is quite risky and costly. There is always the possibility of bridges and buildings collapsing, oil pipelines bursting, chemical plants leaking, and bathroom flooding. Corroded medical implants might result in blood poisoning, corroded electrical connections could start fires and cause other problems, and worldwide air pollution could damage artwork. Corrosion threatens the safe disposal of radioactive waste that should be stored in containers for millennia. This study makes an effort to enhance further the electroplated layer's (Zn-Ni) alloy characteristics. In this study, samples of low-carbon steel are electrodeposited with layers of varying thicknesses of (Zn-Ni) from an alkaline solution throughout various coating times (15, 30, and 60 minutes). The mechanical and corrosion characteristics of the electrodeposits layer are determined using X-ray fluorescence (XRF), which is also utilized to analyse the microhardness and corrosion test results of the (Zn-Ni) deposited layer.Öğe Reducing vibration and noise in the oil sector using nanoparticle-reinforced polymers(Editura Politechnica, 2024) Al-Abboodi, Taif Mohsin Maeli; Alaiwi, Yaser; Al-Khafaji, ZainabVibration in pumps is a common problem and can lead to various problems that can affect the performance, reliability, and safety of the equipment. When pumps vibrate excessively, it can lead to decreased efficiency, increased wear, and premature failure of pump components. Therefore, it is essential to address pump vibration quickly and effectively. Maintenance personnel can take corrective action by monitoring and diagnosing the cause of pump vibration, which will help ensure reliable and efficient pump operation, reduce downtime, and improve workplace safety. This study conducted experimental work to determine the static specifications, such as tensile and tear strength of specimens manufactured from natural rubber reinforced with materials such as ZnO, MWCNTs, and NaHCO3. Another essential dynamic study was performed on a structure of aluminum sheets resting on flexible rubber foundations. The rubber base around the outer bottom border of the metal plate (Al6061) will be 15 mm wide and in three thicknesses (5, 10, 15) mm. In this work, both computational and experimental methodologies for creating elastomers with confirmed material constants are investigated. The FEA analysis of the seventy-two samples showed results related to the fundamental natural frequencies with a maximum variance value of 3.37%.
