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A solar air heater is an effective way to heat air and has applications in heating rooms, drying crops, vegetables and seasoning timber. This study conducted an experiment to evaluate the impact of different slant angles (30°, 45°, 60°) and mass flow rates (0.040 kg·s −1 , 0.045 kg·s −1 , 0.052 kg·s −1 ) of fins on the thermal efficiency of finned plate solar air heaters. A Finned Plate Solar Air Heater (FPSAH) system with an inclined fin array was developed and tested for thermal efficiency. An array of fins with different slant angles was attached to the rear of the absorber plate to improve heat transfer and thermal efficiency. Results showed that the thermal efficiency increased as the slant angle decreased, with the highest thermal efficiency (70 %) and outlet temperature (58.66 °C) achieved at a slant angle of 30° and mass flow rate of 0.052 kg·s −1 . The FPSAH system uses inclined fins to increase solar energy absorption and generate high air temperatures at the outlet. It performs better thermally compared to a solar air heater with a flat plate.

Modifying the geometrical structures is a potential strategy that targets the compactness of any new devices in order to produce greater cooling performance. The heat transfer enhancement over a BFS with unique square-rectangular ribs as FFS in a two-dimensional channel is investigated numerically in this study. Each of the structures features a pair of square-rectangular adiabatic ribs, and both its height and width are adjustable. The ribs are positioned uniformly on the bottom wall heated with uniform heat flux. The impacts of varying number as well as space in between the pair of ribs are also analyzed. Fresh external fluid is entering into the channel from the left and leaving the channel from the right. The methods of solution of the mathematical models are solved numerically following the finite element method along with the Galerkin technique. Through the rigorous computation, the results are obtained and presented systematically over wide range of parametric variations like: with height and width of square-rectangular ribs, space between each pair of ribs, number of ribs, heat flux strength, and flow Reynolds number. In order to compare the thermal performance of BFS with ribs structure, the case of no-ribs channel is also investigated. The results indicate that geometric parameters have major influences on the thermo-fluid flow as well as heat transfer characteristics. It is found that lesser number of ribs with moderate height and width with lesser spacing corresponds to the superior thermal performance compared to no-ribbed channel. Furthermore, lower number of ribs with higher height and width with higher spacing resembles to the worst thermal performance.

A design for a photovoltaic-thermal (PVT) assembly with a water-cooled heat sink was planned, constructed, and experimentally evaluated in the climatic conditions of the southern region of Iraq during the summertime. The water-cooled heat sink was applied to thermally manage the PV cells, in order to boost the electrical output of the PVT system. A set of temperature sensors was installed to monitor the water intake, exit, and cell temperatures. The climatic parameters including the wind velocity, atmospheric pressure, and solar irradiation were also monitored on a daily basis. The effects of solar irradiation on the average PV temperature, electrical power, and overall electrical-thermal efficiency were investigated. The findings indicate that the PV temperature would increase from 65 to 73 °C, when the solar irradiation increases from 500 to 960 W/m2, with and without cooling, respectively. Meanwhile, the output power increased from 35 to 55 W when the solar irradiation increased from 500 to 960 W/m2 during the daytime. The impact of varying the mass flow rate of cooling water in the range of 4 to 16 L/min was also examined, and it was found that the cell temperature declines as the water flow increases in intensity throughout the daytime. The maximum cell temperature recorded for PV modules without cooling was in the middle of the day. The lowest cell temperature was also recorded in the middle of the day for a PVT solar system with 16 L/min of cooling water.

Modifying the geometrical structures is a potential strategy that targets the compactness of any new devices in order to produce greater cooling performance. The heat transfer enhancement over a BFS with unique square-rectangular ribs as FFS in a two-dimensional channel is investigated numerically in this study. Each of the structures features a pair of square-rectangular adiabatic ribs, and both its height and width are adjustable. The ribs are positioned uniformly on the bottom wall heated with uniform heat flux. The impacts of varying number as well as space in between the pair of ribs are also analyzed. Fresh external fluid is entering into the channel from the left and leaving the channel from the right. The methods of solution of the mathematical models are solved numerically following the finite element method along with the Galerkin technique. Through the rigorous computation, the results are obtained and presented systematically over wide range of parametric variations like: with height and width of square-rectangular ribs, space between each pair of ribs, number of ribs, heat flux strength, and flow Reynolds number. In order to compare the thermal performance of BFS with ribs structure, the case of no-ribs channel is also investigated. The results indicate that geometric parameters have major influences on the thermo-fluid flow as well as heat transfer characteristics. It is found that lesser number of ribs with moderate height and width with lesser spacing corresponds to the superior thermal performance compared to no-ribbed channel. Furthermore, lower number of ribs with higher height and width with higher spacing resembles to the worst thermal performance.

The performance, safety, and cycle life of lithium-ion batteries (LiBs) are all known to be greatly influenced by temperature. In this work, an innovative cooling system is employed with a Reynolds number range of 15,000 to 30,000 to minimize the temperature of LiB cells. The continuity, momentum, and energy equations are solved using the Finite Volume Method (FVM). The computational fluid dynamics software ANSYS Fluent is applied to calculate the flow and temperature fields and to analyze the thermal management system for 52 LiB cells. The arrangement of batteries leads to symmetrical flow and temperature distribution occurring in the upper and lower halves of the battery pack. The impacts of SiO2 distributed in a base fluid (water) are investigated. The results show that SiO2 nanofluid with the highest volume fractions of 5% has the lowest average temperature values at all investigated Reynolds numbers. The innovative cooling system highlights the enhancement of the cooling process by increasing the SiO2 concentrations, leading to the recommendation of the concentration of 5 vol% due to better thermal diffusion resulting from the enhanced effective thermal conductivity. The flow turbulence is increased by increasing the Reynolds number, which significantly enhances the heat transfer process. It is shown that increasing the Re from 15,000 to 22,500 and 30,000 causes increases in the Nu value of roughly 32% and 65%, respectively.

This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT) collector and compound parabolic concentrators (CPC) on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar cells. The electrical efficiency and power output are directly correlated with the mass flow rate. The results show that electrical efficiency was improved by 7% when using CPC and jet impingement cooling in a PVT solar collector at 1:00 p.m. (solar irradiance of 1050 W/m2 and an ambient temperature of 33.5 °C). It can also be seen that the power output improved by 36% when using jet impingement cooling with CPC, and 20% without CPC in the photovoltaic (PV) module at 1:30 p.m. The short-circuit current ISC of the PV module experienced an improvement of ~28% when using jet impingement cooling with CPC, and 11.7% without CPC. The output of the PV module was enhanced by 31% when using jet impingement cooling with CPC, and 16% without CPC.

This study aims to investigate the thermal behavior and aerodynamic phenomena in a heated channel with varied rib configurations using computational fluid dynamics (CFD) simulations. Incorporating ribs in such systems enhances heat transfer and increases flow resistance and manufacturing costs. Understanding heat exchanger theory, measurement methods, and numerical calculations are crucial for creating efficient heat exchangers. The current research employs numerical analysis to assess the impact of hybrid ribs on heat transfer enhancement in forward-facing contracting channels (FFS). A two-dimensional forced convection heat transfer simulation under turbulent flow conditions was performed, considering the presence and absence of ribs with dimensions of 1 cm by 1 cm and spaced 11 cm apart. The arrangement of the ribs causes symmetrical temperature and flow distribution after and before each rib. The results demonstrate that the use of hybrid ribs outperforms the use of individual rib configurations in terms of thermal performance. This is due to the distinct flow patterns generated as the fluid passes through each rib. The triangle ribs had a more significant impact on the pressure drop than other rib configurations, while the cross ribs showed a lesser effect. The ribs improve the heat transfer coefficient while increasing the pressure drop, and the values of the Reynolds number were found to be directly proportional to the heat transfer coefficient and the pressure drop. The study concludes with a qualitative and quantitative analysis demonstrating the accuracy and coherence of the obtained computational results.

The performance, safety, and cycle life of lithium-ion batteries (LiBs) are all known to be greatly influenced by temperature. In this work, an innovative cooling system is employed with a Reynolds number range of 15,000 to 30,000 to minimize the temperature of LiB cells. The continuity, momentum, and energy equations are solved using the Finite Volume Method (FVM). The computational fluid dynamics software ANSYS Fluent is applied to calculate the flow and temperature fields and to analyze the thermal management system for 52 LiB cells. The arrangement of batteries leads to symmetrical flow and temperature distribution occurring in the upper and lower halves of the battery pack. The impacts of SiO[sub.2] distributed in a base fluid (water) are investigated. The results show that SiO[sub.2] nanofluid with the highest volume fractions of 5% has the lowest average temperature values at all investigated Reynolds numbers. The innovative cooling system highlights the enhancement of the cooling process by increasing the SiO[sub.2] concentrations, leading to the recommendation of the concentration of 5 vol% due to better thermal diffusion resulting from the enhanced effective thermal conductivity. The flow turbulence is increased by increasing the Reynolds number, which significantly enhances the heat transfer process. It is shown that increasing the Re from 15,000 to 22,500 and 30,000 causes increases in the Nu value of roughly 32% and 65%, respectively.