Engineering and Technology Journal

Increasing global economic development leads to a continuous increase in energy demand, considering the limited conventional resources of energy as well as the impact on the environment associated with its use. The primary disadvantage of solar energy is that it is only accessible during the day. Thermal energy storage systems can overlook this flaw since they can store energy throughout the day for use at night. This paper presents a new cooling technique for low-concentration parabolic collectors with microchannel and Phase Change Material (PCM). A test model consisting of a parabolic concentrator was designed and fabricated to test the parabolic concentrator with and without PCM in Baghdad city during January, March, and July. The solar receiver is an essential component of a solar-powered system and was manufactured from Aluminum metal with 44 microchannels (0.3 m in length, 0.02 m in width, and 0.009 m in height), where the receiver consisted of four rows of microchannels, each row consisting of 11 channels is constructed with velocity and temperature measurement facilities to achieve the experimental results. The results show that the PCM will store the energy roughly three hours after sunset at a flow rate of 0.009339 kg/s. Also, the result indicated that the two-axis tracking system would increase thermal efficiency.

Photovoltaic panels are considered one of the important practical applications in converting solar energy into electrical energy, but they suffer from the effect of heat associated with solar radiation. Therefore, much research has been done to either harness the heat that comes with it or eliminate it by cooling the panel and boosting its effectiveness. In this work, a cooling box was designed and manufactured locally (the passage design is new) that is attached to the back wall as part of the panel without inserting an absorbent portion between it and the water to cool the panel. The new model was subjected to numerical and experimental tests to ascertain its efficacy in raising PV panel efficiency. ANSYS R19.2 software was used to compare numerical simulations with experimentally obtained results. The results showed good agreement between the two tests. The results also showed that the new model was able to raise the electrical efficiency of PV panels compared to the results of traditional panels without cooling, from 12.97% under the radiation intensity of 1035 W/m² to 14.87% under the same radiation intensity at a water flow rate of 4 L/min, this means an improvement of up to 12.78%. On the other hand, the control system reduced water consumption by 29.28% of the consumed water to maintain the efficiency ratio at semi-stable levels to its highest value of 15.37%, thus achieving an improvement of up to 15.56% for the same conditions above.

The increasing demand for sustainable and renewable energy sources has prompted extensive research into alternative biomass fuels, particularly in regions like Nigeria, where traditional wood-based fuels are prevalent. A comprehensive experimental analysis of briquettes derived from various wood sources found in Nigeria aims to assess their combustion characteristics and potential as a viable alternative to traditional fuels. The selected wood species include indigenous varieties known for their abundance and accessibility. This study examines the physical and thermal properties of briquettes made from six wood types commonly found in Nigeria: Ayo, Obobo, Obeche, Araba, Afara, and Eku. From the experiment study, the flame propagation rate, afterglow time of the briquettes, calorific value, and heat combustion value 0.72 to 0.73, 408 to 415 sec, 18,745 to 34,857 kJ/kg, and 17079 to 20012 kJ/Kg respectively. The experimental analysis of the briquettes showed that their physical and thermal properties varied, with notable differences in calorific value and propagation rate. The data suggests that the composition and density of wood play a significant role in determining the efficiency and performance of the briquettes. This research addresses the technical aspects of briquette combustion and emphasizes the potential socio-economic and environmental benefits of adopting such alternative fuels. This study's outcomes can guide future initiatives in the quest for cleaner and more sustainable energy practices in Nigeria, aligning with global efforts to mitigate the impact of traditional biomass consumption on the environment and public health.

The two-dimensional numerical simulations focused on fluid flow and heat transfer within a solar air heater (SAH) channel incorporating copper metal foam with a porosity of 90% were carried out in this study. The Local Thermal Non-equilibrium (LTNE) and Darcy-Extended Forchheimer (DEF) models were employed to predict fluid and thermal transport in the partially porous SAH channel. In the free flow zone, the turbulence model was utilized. The thermal and thermo-hydraulic performances of SAH were examined concerning several factors, including pore density ( ), Reynolds number ( ), and dimensionless foam height ( ). The results demonstrate that inserting a porous substrate into the SAH can substantially increase heat transmission. This enhancement ranges from 4.4 to 18.04 times compared to an empty duct for at . Moreover, increased porous layer height and pore density lead to a corresponding increase in pressure drop. Evaluating both the improvement in heat transmission and the associated pressure penalty, the case with , and demonstrate superior overall performance, boasting a higher Thermal Performance Factor ( ) of 2.82 when compared to an empty channel. This work presents significant findings on optimizing metal foam applications in SAH systems, offering new insights into the field.

In this study, the effect of an electronic control system (ECS) on the performance of a solar heater fabricated from recycled materials was investigated . The study found that the maximum thermal energy output before installing the ECS stood at 378 W, which was significantly improved to 450 W after integration, indicating a commendable enhancement in the efficiency of the solar heater. The thermal efficiency of the solar heater also saw a substantial jump from 71.7% to 82% after connecting the ECS. The study also uncovered the temperature disparity between the trapped and ambient air (max. ΔT = 20.4 °C) influenced heat loss from the space between the glass cover and the two heat exchangers. To address this issue, the sides and base of the heater assembly were insulated with foam material to minimize heat loss. Furthermore, the ECS was programmed to regulate the water flow rate in the solar collector to prevent the water temperature from surpassing 65 °C in winter and 40 °C in spring and autumn. The study harnessed solar panels to provide electricity to the ECS, which enabled the technology to adapt the solar heating process according to environmental conditions and user needs. The study's findings demonstrate the potential of utilizing an ECS for recycling waste solar heaters, leading to enhanced heat transfer efficiency and long-term financial and environmental benefits.

In remote areas, a scarcity of accessible water poses a significant predicament, and sun-powered propelling contraptions offer promising solutions. It is possible to collect solar energy with the goal of raising a fluid. Bubble pumps are used in the process of creating two-phase flows via the boiling of fluids in diffusion-absorption refrigeration cycles. In this investigation, a solar-powered bubble pump lifted the water. EES, which stands for engineering equation solver, was used in order to carry out the theoretical study of the bubble pump technology. Based on the results, it was determined that the void fraction displays a pattern that is comparable in applications using diffusion absorption refrigeration. In addition, the maximum water lift occurs at a certain heat flux value and any rise that is greater than this threshold causes the bubble pump to collapse entirely. Empirical tests were conducted utilizing bubble pumps with diameters of 8 mm and 10.21 mm to raise water across a distance of 4.53 m. The experiments examined a certain range of heat flow values at specified submergence ratios. According to the testing results, increasing the heat flux within the prescribed range significantly increased the 10.21 mm bubble pump's ability to lift water, yielding a maximum increase of 21%. According to the findings of the study, a universal set of optimal conditions and values for the bubble pump is not feasible to ascertain. This is because every system possesses distinct characteristics and operational elements that necessitate the utilization of optimized parameters for optimal performance.

Wind energy has become an easy-to-harness source by converting captured wind currents into electrical energy. Powerful and customizable wind turbines are used to convert wind energy efficiently. However, wind turbine development in terms of structure is still an active area of research aiming at efficiently building capable and long-lasting turbines. Additive manufacturing technology, particularly 3D printing, has revolutionized multiple industries, including its potential to create wind turbine blades with high cost-effectiveness and optimizable shapes and rigid structures. In this review, various 3D printing-based techniques, including Fused Deposition Modelling (FDM), Continuous Fiber Reinforcement (CFR), Stereolithography (SLA), and 3D Printing-enhanced Large-Scale Additive Manufacturing (LSAM), are examined in detail for complex and large-scale wind turbine blade production. Materials used in 3D printing wind turbine blades, such as thermoplastic composites, epoxy resins, and fiber-reinforced polymers, are assessed with a focus on their mechanical strength, durability, and environmental considerations. Furthermore, the importance of design optimization and customization for wind turbine blades, including aerodynamic and structural design optimization, is emphasized. Customization for site-specific conditions, infill structural optimization, and infill printing speed and cost are also discussed. The review highlights the importance of structural optimization in developing efficient and cost-effective 3D-printed wind turbine blades, customization for site-specific conditions, and infill structure. The review also mentions these technologies\' challenges, such as material limitations, surface finish quality, size limitations, and structural integrity. Therefore, addressing these challenges to utilize these technologies\' potential fully is crucial.

The present study delves into the incremental hole flanging process applied to AA1050 and DC01 sheet metals with 0.7 and 1 mm thicknesses. Employing a distinctive lathe-based fixture, the process utilizes a proposed tool profile and fixture incorporating mutually spinning and rolling motions. The investigation covers three forming angles (72°, 90°, and 45°) and three different rotational forming speeds (170, 350, and 525 RPM). The primary objective is to assess the impact of tool forming angle, forming speeds on microhardness, thickness ratio, and forming limit diagram. The study employs a microhardness test, measurements of flange height, and final thickness. Results revealed hardness and thickness variations depending on material type sheet thickness, showing a critical forming speed at which a critical change in variation trend occurs irrespective of forming angle. Forming speed and tool profile were selected carefully to produce a maximum forming limit and a large amount of plastic deformation with no failure of metals. Hardness distribution experienced smooth variation, and the maximum increase in post hardness didn’t exceed 73% without evidence of crack formation at the end of the process. As well as the thickness distribution shows a uniform variation along the flange profile with a maximum thickness reduction of 40% and 51% for 1 mm DC01 and AA1050 sheets, respectively. Finally, based on the proposed tool geometry and holding arrangement adopted in the present work, results indicated a good enhancement in forming limit is satisfied with no obvious large thinning occurring due to change in deformation modes can be used successfully in incremental hole flanging process.

This comprehensive research paper reviews the latest techniques to enhance the productivity of double-slope solar stills by providing quantitative data on key research outcomes. With the global water scarcity crisis and the need for effective desalination technology, this study focuses on solar-based desalination techniques and their specific application in double-slope solar stills. This paper offers a comprehensive and quantitative analysis of heat addition methods in double-slope solar stills by examining published research findings, providing valuable insights for researchers and practitioners. The study reveals significant improvements in productivity through various modifications. Evaporation enhancement, heat transfer enhancement, and condensation enhancement have proven to be highly effective, resulting in substantial increases in water production. The use of thermoelectric modules in double-slope solar stills has shown a remarkable 250% increase in water production by heating the water in the basin, which enhances evaporation rates and condensation on the glass cover. Moreover, the integration of Evacuated Tube Collectors (ETCs) has demonstrated a notable improvement in double-slope solar stills' life cycle conversion efficiency. The system incorporating ETCs achieved an impressive 59.42% higher efficiency than a system without ETCs, primarily due to the enhanced thermal input provided by ETCs to the solar still's basin. Another significant finding is the six-fold increase in water production achieved by implementing the double-slope solar still with a PV heater (CSSPVH) compared to conventional solar stills (CSS). This substantial improvement positions the CSSPVH design as a highly efficient solution for long-term potable water generation. Furthermore, adding a water heater to the base tank of a solar still has been found to raise water temperature quickly, resulting in a significant boost in production by approximately 370%. However, it is important to note that productivity decreases with increasing wind speed. Even with an outer cooling fan to cool the solar still's glass surface, productivity is reduced by 4% and 8% for wind speeds of 7 m/s and 9 m/s, respectively.

The characterization of raffia palm fibre (RPF) for reinforcement in polymer composite for specialized applications was studied. The fibres were treated with NaOH solution and subjected to a tensile strength test. The fibres were also subjected to spectroscopy using Fourier transform infrared (FTIR), energy dispersive x-ray fluorescence (EDXRF), and x-ray diffraction (XRD). The study found that the alkaline-treated RPF presented a tensile strength of 195 MPa and Young’s modulus of 91.76 MPa. The strain at maximum stress in the fibre was found to be 2.125%. FTIR spectra of treated raffia palm fibres revealed that the fibres are characterized by O-H and C-H stretching. There is the presence of carboxylic acids, functional groups of methyl (CH3), methylene (CH2), and aliphatic saturated (CH) compounds. There was no observed peak at around 1000 cm-1 to 650 cm-1 bands characterized as the C-H ―oop‖ bond structure of a functional group of aromatics. The absence of a peak in the range indicates that the alkaline treatment of RPF has been effective, as evidenced by the absence of smell. EDXRF showed significant Ca, Fe, and K concentrations in raffia palm fibres. The XRD results show that RPF is semi-crystalline, with the crystalline index estimated at 57.3%. Therefore, RPF can be used as potential reinforcement in polymer composite applications where moderate strength and stiffness are required. From the spectroscopy, RPF is safe for deployment as an alternative source of reinforcement in polymer composites, especially for developing biomedical applications such as prosthetics and wheelchairs.

Atmospheric Water Generation assumes substantial significance as an innovative remedy for addressing water scarcity and augmenting water resilience. This technology facilitates water extraction directly from the atmosphere, presenting a sustainable and decentralized approach to water supply. The investigation into the feasibility of attaining the dew point temperature for a heatsink operating in the climatic conditions of Basra was conducted using Fluent 22.1 software. The minimum dew point temperature under extreme conditions was determined to be 10.52℃. A thermoelectric device was a primary component in cooling the moisture-laden air to produce water from atmospheric air. Simulations were executed using two complementary and two integrated heatsinks under turbulent airflow conditions ranging from 4 to 20 m/s. The results indicated an inverse relationship between heat distribution within the heatsink and fluid flow velocity, emphasizing the crucial role of airflow passage arrangement in the condensation process. Enhancing the heatsink's surface area and reducing airflow quantity proved effective in achieving the dew point temperature. The lowest temperature attained was 9.2℃, featuring intersecting heat exchangers with a flow velocity of 4 m/s. The result indicated that altering the flow pattern affects the condensation process's surface temperature by as much as 38%, while the rise in pressure difference can reach 20%. Under the same operational conditions, the difference in thermal conductivity between two distinct heat exchanger configurations, attributed to pressure variations, is notably 8%. The study concludes that the Qurna region benefits from favorable weather conditions, encompassing temperature and relative humidity, thereby enabling water generation from atmospheric air, notwithstanding the consideration of the dew point temperature as a limiting factor.

High-density polyethylene (HDPE), like other polymers is important in many applications due to its unique properties like low cost, weight, and availability. Recently, HDPE reinforced with ceramic fillers was considered in biomedical applications, especially in fabricating joint/bone replacements. Therefore, these applications required high wear resistance materials to serve under specific conditions. In this work, an optimization with Taguchi method was considered to associate the influence of nano alumina fillers, normal applied load, and sliding time on the wear rate values for hip joint replacement applications. In the first step, a TEM test was conducted on the prepared composites to ensure that the nanofillers were distributed within the matrix phase without agglomeration. The results indicated that the optimum wear resistance was seen in a composite made of HD PE +3% wt nano alumina fillers with a specific wear rate equal to 2.6652 10-6 in mm3/N.m, as well as the most effective parameters on wear rate are arranged as nano content, applied load, and the sliding time. In contrast, SEM observation was considered to understand the wear mechanism. The addition of nano Alumina fillers prevented the test specimen surface from lessening by creating a transfer film separating the contact zone results from the self-lubricant behavior generated in prepared composites. In contrast, deep grooves, adhesive marks, and debris particles were generated in pure HDPE specimens, resulting in low hardness and weak wear resistance.

Indonesia faces a significant challenge in managing its waste effectively. Conventional incineration, while reducing waste volume, raises environmental concerns due to emissions. This research explores a novel approach by developing a thermoelectric incinerator prototype with a 10 kg/hour capacity. The incinerator aims to convert heat generated during waste incineration into electrical energy, offering an environmentally friendly alternative for waste management. The research involved designing and modeling the incinerator using Ansys Fluent 2021 R1 software. Incineration tests were conducted experimentally using 5 kg organic and 5 kg inorganic waste for 30 minutes. Critical parameters such as temperature distribution, moisture content, calorific value, combustion temperature, generated voltage, and ash production were analyzed. The analysis revealed good temperature distribution through Computational Fluid Dynamics (CFD) simulations, enabling the optimization of air and heat flow within the incinerator. Organic waste with a water content of 13.93% and a calorific value of 5327.76 cal/gram reached a combustion temperature of 181 °C. In comparison, inorganic waste (water content: 2.39%, calorific value: 10846.58 cal/gram) achieved a temperature of 210 ℃. The maximum voltage generated was 2.1 V for organic waste and 2.2 V for inorganic waste. Notably, the incineration process was reduced by 72% for organic waste and 68% for inorganic waste, highlighting its effectiveness in volume reduction. This thermoelectric incinerator prototype offers several advantages: a high level of waste reduction, a modular design facilitating easy assembly and disassembly, and the ability to handle various types of waste as fuel.

Hybrid composite sandwich structures, known for remarkable energy absorption, rigidity, and strength, are emerging as a preferred choice for fortifying structures against a diverse range of firearms and artillery. Despite their higher density, these panels demonstrate commendable qualities, making them optimal for armored vehicles and body armor. Numerous structural options compete for recognition as effective ballistic shields in today\'s context. In this study, three sample configurations were rigorously tested for ballistic impact using a 7.62×39 mm bullet. The first sample (S1) comprised silicon carbide ceramic tiles (SiC), Kevlar fiber, and carbon fiber in the face sheet, with an unfilled aluminum honeycomb core and a carbon fiber rear sheet. Subsequent samples, S2 and S3, maintained the S1 composition but varied in the core. S2 had a honeycomb core injected with polyurethane foam, while S3 utilized a silicone rubber-filled honeycomb core. Ballistic tests revealed a notable difference: S1 and S2 failed to prevent bullet penetration, whereas S3 successfully met this crucial objective. After penetration, the bullets\' velocities were S1 -45.9 m/s, S2-22.9 m/s, and S3 -0m/s. Remarkably, S3 exhibited an optimal 0mm back face signature (BFS) and a penetration depth (DOP) of 13.74 mm, well within limits. Cumulative energy absorption (EA) was as follows: S1-2577.23 J, S2-2583.57 J, and S3-2617.92 J. The armors demonstrated specific energy absorptions (SEA) of 2386.33, 2389.97, and 2015.32 J/kg, respectively. Their areal densities were 48, 48.1, and 57 kg/m2, respectively. The ballistic limit velocities (BLV), derived from initial (IV) and residual velocities (RV), measured 802.68, 803.673, and 804 m/s for S1, S2, and S3.

The study aims to estimate the performance and emissions of a gasoline direct injection (GDI) engine by analyzing parameters such as engine speed between 2000 and 6000 rpm, compression ratio (CR) between 9 and 13, and the start of ignition between 140 and 180 deg. A thermodynamic mathematical model was developed using MATLAB to simulate the two-zone combustion process of a four-cylinder, four-stroke direct injection engine operating on gasoline at specified parameters. The results showed that parameter variations greatly affect the performance and emissions of the GDI engine. The highest values of in-cylinder pressure, burned and unburned temperature, cumulative engine power, Carbon monoxide CO and Nitrogen oxide NO emissions were found at low engine speeds, while heat transfer increased as engine speed increased, and it's been noticed that the maximum power per cycle at speed (2000 rpm), fuel injection pressure (40 MPa), and S.O. ignition angle (165). Increasing the compression ratio between 9 and 13 increased cylinder pressure, but it is observed that a compression ratio has a minimal effect on the temperature in both the burned and unburned areas. Cumulative engine power and heat transfer decreased when the compression ratio rose, and the percentage mole fraction of CO and NO emissions decreased with increasing CR. The engine observed maximum power per cycle at a compression ratio of 10, an engine speed of 2000 rpm, and a cylinder bore/stroke ratio of 100%. Advancing the spark timing increased in-cylinder pressure and burned and unburned temperatures while delaying the ignition timing increased heat transfer. It is also noticed that in cylinder pressure, burned, and unburned temperatures increase when spark timing is advanced. As the ignition timing was delayed, heat transfer increased. In contrast, the minimum cumulative engine power at the advanced spark timing and the peak power values at the ignition angle were 170 deg. The peak values of the percentage mole fraction of CO and NO emissions at early spark timing. Also, maximum power per cycle at ignition angle (170 deg.), engine speed (1500 rpm), and engine load (75%).

A solar-assisted heat pump system is a hybrid system that integrates a solar collector and a heat pump, serving diverse functions such as space conditioning, drying, and generating heated water. The system's classification is based on the connection configuration of the solar collector and heat pump, which may involve a serial, parallel, or dual arrangement. Solar-assisted heat pump systems enhance output efficiency by harnessing solar energy in various heating modes, with the effectiveness contingent on the prevailing environmental conditions. As stated above, these systems are essential in lowering power consumption and reducing emissions. This study comprehensively assesses the research and development of solar-assisted heat pumps for building applications. This study delves into the classification of these systems, including direct expansion and indirect expansion solar-assisted heat pumps. Each configuration is to be detailed, and their thermal performance and demonstration samples are thoroughly examined. Furthermore,
the study includes the assessment of energetic indicators for individual
components and the overall system. Additionally, an investigation has been
conducted on various refrigerant types that show promising potential for use in
solar-assisted heat pump systems. It shows that adding an air evaporator to direct
expansion solar-assisted heat pump solves the systems' deterioration during the
absence of solar energy. The effect of climate on the indirect solar-assisted heat
pump can be solved by designing the system to work in parallel or series
configuration, depending on the solar energy availability.

High heat generation is the main problem that sophisticated electronic devices can suffer. The pool boiling process can offer an excellent heat dispassion at constant temperatures. Therefore, it is one of the most powerful cooling processes used in nuclear power plants, data centers, air conditioning, etc. Because of that, enhancing pool boiling has become a goal of many recent investigations. The current paper presents an experimental study to evaluate the effect of nano and nanocomposite coating on the performance of pool boiling of deionized water under atmospheric pressure. Four surfaces made of copper were used in this study: smooth, CNT (1 g), GNPs (1 g), and (CNT-GNPs (1:1) g) surfaces. A four-step electro-deposition method was used to fabricate a nickel coating using the abovementioned materials. The variation in coating materials offers different surface wettability and roughness to the fabricated surfaces. The experiment's outcome revealed that the hydrophilic material can enhance the critical heat flux (CHF). The mixed wettability obtained by the nanocomposite coating can improve the heat transfer coefficient (HTC). Maximum enhancement in the CHF is obtained by GNPs (1 g) surface with 102%, while the maximum HTC is obtained by (CNT-GNPs (1:1) g) surface with 154% when it is compared with the plain surface.