This study presents a detailed numerical analysis of substrate boards made from various materials (FR-4, Si cladding, and Cu cladding) with nine electronic components mounted on them. Each component is subjected to different heat fluxes, and the analysis covers both natural convection (NC) and forced convection (FC) modes of heat transfer at air velocities of 4m/s and 6m/s. The findings reveal that at an air velocity of 6m/s, using a copper cladding board significantly lowers the temperatures of the electronic components by 340C to 540C compared to FR-4 and Si cladding boards. Additionally, the copper cladding reduces the required air-cooling velocity by 2m/s and achieves a temperature reduction for the IC chips ranging from 3.500C to 13.120C. It is recommended to use an air velocity of 4m/s with copper cladding to minimize fan power consumption while maintaining component temperatures below 1250C. These results provide crucial insights for thermal design engineers, aiding in the selection of appropriate substrate boards for effective thermal management of electronic components. The study emphasizes the benefits of copper cladding in distributing heat more uniformly, reducing energy consumption, and maintaining optimal operating temperatures. Furthermore, it suggests that placing high heat-dissipating components at inlet or outlet points can minimize thermal interactions and overall configuration temperatures. The research offers valuable guidance to the heat transfer community, particularly electronic thermal designers, by highlighting the importance of substrate material choice and component placement in enhancing the reliability and lifespan of integrated circuits (ICs). The comprehensive analysis and recommendations serve as a vital resource for optimizing thermal control strategies in electronic devices, ultimately contributing to improved performance and durability.
15 September 2024 in Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
In the present study the experiments were conducted on steady-state that incorporated nine symmetric and asymmetric separate discrete integrated circuits (ICs), strategically positioned at different locations on a substrate board, both with and without phase-change material (PCM). These ICs were subjected to varying levels of heat flux. It has been noted that the temperature is highly influenced by variables such as the size and positions of integrated circuits (ICs), the heat flux applied to the ICs. Furthermore, the non-dimensional geometric distance parameter, λ, is notably affected by both the size and positioning of the ICs. It's observed that at a higher value of λ (0.19), the temperature decreases by 18.79% at a velocity of 3 m/s and by 26.48% at a velocity of 5 m/s without PCM. With PCM, the temperature drop is 23.58% at 3 m/s and 32.47% at 5 m/s. The correlation shows a regression of 0.97 and an RMS error of 0.012%. A proposed correlation establishes a connection between θ (non-dimensional temperature) and λ, suggesting that the maximum non-dimensional temperature (θ) decreases with an increase in λ. This implies that the maximum temperature of the integrated circuits (ICs) is reduced at higher λ values. These findings provide valuable insights for thermal design engineers, aiding them in optimizing the placement of integrated circuits (ICs) to improve the reliability and lifespan of the ICs.
30 September 2024 in Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
This study explores the impact of wavy corrugated twisted tape inserts on enhancing heat transfer and reducing pressure drop in a double pipe heat exchanger. Cu inserts with twist ratios of 3.2, 4.2, and 5.2 were used to create turbulence in the inner tube. Varying water flow rates and measuring bulk mean temperatures at different points revealed significant improvements in heat transfer over smooth tubes. The insert with a 3.2 twist ratio achieved the highest Nusselt number increase (185%) and a 36.33% rise in the friction factor. These results highlight the effectiveness of wavy corrugated twisted tape inserts for optimizing heat transfer, with a 3.2 twist ratio identified as the most effective. Across Reynolds numbers from 4000 to 18000, Nusselt number increases were 77.75% for a 5.2 twist ratio, 167% for a 4.2 twist ratio, and 185% for a 3.2 twist ratio. Friction factors rose by approximately 10.42% for a 5.2 twist ratio, 32.54% for a 4.2 twist ratio, and 36.33% for a 3.2 twist ratio, demonstrating the relationship between twist ratio, heat transfer enhancement.
20 October 2024 in Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
This study investigates the heat transfer and friction factor characteristics in a heat exchanger utilizing copper wavy (corrugated) twisted tape inserts. By inducing turbulent flow within the inner tube of the heat exchanger, these inserts generated increased turbulence, thereby enhancing heat transfer and causing a rise in pressure drop. The copper twisted tapes, with various twist ratios (TR=10.7, 8.5, 7.1), measured 1 meter in length and 14 mm in width. The heat exchanger's outer tube was made of mild steel, with an outer diameter of 0.0198 m and an inner diameter of 0.0142 m, while the inner tube was constructed of copper, with an outer diameter of 0.038 m and an inner diameter of 0.032 m. The overall length of the pipe-in-pipe heat exchanger was 1.4 m. Bulk mean temperatures were recorded at different positions for various water flow rates, and new correlations for the Nusselt number and friction factor were derived from the results for the twisted tape inserts. The Reynolds number ranged from 5000 to 17000. Comparative analyses revealed that the wavy twisted tape with a twist ratio of 7.1 provided the highest heat transfer rate, showing a 172% increase in the Nusselt number and a 32.11% increase in the friction factor relative to a smooth tube.
10 October 2024 in Journal of Advanced Research in Fluid Mechanics and Thermal Sciences
This study focuses on analysing the impact of seasonal variations in heat on different parts of a "wind energy system," serving as a representative mechanical system. The proposed methodology utilizes wind rose analysis, offering a straightforward means to assess heat transfer effects, applicable to any mechanical system comprising numerous small heat-dissipating components. Furthermore, this work elucidates the correlation between mechanical component performance and heat dissipation impact, providing breakdown alerts for various wind turbine components. Additionally, it analyses the influence of mechanical part temperatures on energy generation, highlighting how high temperatures can indicate component deterioration, such as bearing damage. Notably, the study focuses on wind speeds ranging from 10 to 15 m/s, a typical operational range for wind turbines. By employing wind rose charts and real-time readings, the graded heat dissipating potential of mechanical parts under various wind velocities and weather conditions is determined. Moreover, the study emphasizes the significance of heat transfer analysis in optimizing wind turbine performance, demonstrating how temperature differentials between mechanical components and the environment, along with increased surface area, affect heat transfer. The proposed analysis underscores the importance of considering heat's impact on each mechanical component in tandem with seasonal environmental temperature fluctuations. The wind rose methodology, integrated with sensor implantation, emerges as a cost-effective tool for studying -level heat variances in mechanical systems, enabling the development of heat profiles for future turbine designs and computational fluid dynamics (CFD) analyses. As heat transfer coefficient increases the wind turbine performance decrease. The heat transfer coefficient decreases 14.28% from rainy to winter season and 42.85% from winter to summer season. The wind rose analysis provides valuable insights into wind patterns and characteristics at a specific location, which can inform decision-making in various fields such as energy, construction, environmental management, and safety planning. As the turbine temperature increases the wind velocity decreases. Here it decreases 28 % from rainy to winter season.
30 November 2024 in Journal of Advanced Research in Numerical Heat Transfer
Modern smartphones are used for a wide range of demanding tasks, such as gaming, high-resolution photography, and internet browsing, which significantly increases their power consumption. This excessive power use leads to higher heat generation within the device, typically between 2 and 6 watts. To manage this heat and maintain optimal performance, smartphones employ various cooling techniques. A new mobile cooling method could use innovative approaches like advanced phase change materials, liquid cooling systems, or emerging technologies such as thermoelectric and microfluidic cooling. This paper proposes a new cooling method using phase change materials. This approach leverages the material's ability to absorb heat by transitioning from a solid to a liquid state and vicecersa. This helps keep the device's temperature below 45 degrees Celsius. In mid-range smartphones, cooling methods such as natural convection, indirect heat-pipe cooling, and forced convection are commonly used, but these methods often fail under high-power usage conditions.