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This study investigates the structural displacements induced by aerodynamic loads in a future particle detector at the Large Hadron Collider (LHC): the Inner Tracking System 3 (ITS3) of the ALICE experiment. The development of an ultralight structure and use of air cooling lead to an unprecedentedly low material budget, resulting in improved accuracy compared to the current detector (ITS2). The airflow applied to the low-mass structure of the ITS3 is expected to cause vibrations, which requires an aeroelastic analysis that is performed using experimental and numerical methods. A novel experimental approach is proposed using confocal chromatic sensors to measure the structural displacements of an ITS3 prototype with submicron accuracy. A simplified mathematical model is developed for the fluid-structure interaction. The results obtained in the experimental setup show that the numerical model predicts the primary peaks in the spectrum of structural displacements induced by airflow. The validated model is used to analyze both the real anticipated configuration of the future ITS3 setup and potential modifications arising from changes in detector cooling and installation requirements. • Aeroelastic study of the ALICE Inner Tracking System 3 conducted. • Use of confocal sensors with submicron accuracy to measure structural displacements. • Development of a customized model for fluid-structure interaction analysis. • Experimental validation to predict natural frequencies and spectrum peaks. [ABSTRACT FROM AUTHOR]

The numerical modeling of the effect of wind direction and velocity over the air cooling of PV panels with heat sinks is realized. During the study, a random PV panel with typical characteristics was analyzed for three different wind directions—towards its back, towards its front and from the side. The analysis was realized on a fixed PV panel, oriented to the south, with an inclination of 45 degrees from the horizontal position. The accuracy of the numerical simulation was achieved by comparison with the experimental studies presented in the literature and by comparing the NOCT conditions. The numerical study is focused on different types of heat sinks attached to a typical PV panel. The fins were distributed both horizontally and vertically. A challenging task consisted in simulation of the real wind conditions around the PV panel by taking into account the entire air domain. The simulations were realized for air velocity vair from 1 m/s to 5 m/s, solar radiation of G = 1000 W/m2 and ambient temperature tair = 35 °C. The output parameters analyzed were the average temperature of PV panels and their power production. Although the lowest temperatures were achieved for the back wind, the cooling effect was more intense for the side wind. The other direction studied also determined the cooling of PV panels. The passive cooling solutions analyzed introduced a rise of maximum power production between 1.85% and 7.71% above the base case, depending on the wind direction and velocity. [ABSTRACT FROM AUTHOR]

In this article, a multiparameter model order reduction (MOR) is applied to the thermal modeling and simulation of power electronics modules and air cooling systems. Although widely employed, simulation tools based on finite elements (FE) or finite difference methods result in computationally expensive models that hamper the analysis in studies where one or more parameters are changed. MOR techniques can be applied to reduce the computational complexity. However, standard reduction techniques cannot easily consider parameters variability and need to be reapplied for each parameter value. This article proposes a multiparameter order reduction technique that can significantly improve the thermal simulation efficiency without having a significant impact on the prediction accuracy. The method is applied to multichip SiC power module mounted on a forced air-cooled finned heatsink with variable air flow. [ABSTRACT FROM AUTHOR]

Highlights • Battery cell spacing distribution of the parallel air-cooled BTMS is optimized. • Optimization is conducted by a strategy for homogenizing the airflow rates. • An adjustment coefficient is introduced to improve the optimized result. • Cooling efficiency of the BTMS is improved remarkably after the optimization. • The present optimized results are better than the ones in previous studies. Abstract In this paper, the cell spacing distribution of the battery pack in the parallel air-cooled BTMS is designed to improve the cooling efficiency of the system. The flow resistance network model is used to calculate the airflow rates in the cooling channels. A modification factor is introduced to reduce the error of the model. The effectiveness of the model is verified by the computational fluid dynamics (CFD) calculation, and the CFD method is validated by the experimental air-cooled system with aluminum blocks. Combining with the improved flow resistance network model, an optimization strategy is adopted to optimize the battery cell spacings for the homogenization of the airflow rates among the cooling channels. Then an adjustment coefficient is introduced to adjust the airflow rates in the cooling channels for more uniform cell temperatures. The results of typical numerical cases indicate that the cooling efficiency of the BTMS is improved remarkably after the cell spacing optimization using the developed strategy. Compared to the original BTMS, the maximum temperature of the battery pack for the optimized BTMS is reduced by about 4.0 K, and the maximum cell temperature difference is reduced by more than 69% for various inlet airflow rates. Compared to the optimized BTMS in previous study, the maximum cell temperature difference for the present optimized BTMS is reduced by more than 25% for various inlet airflow rates. [ABSTRACT FROM AUTHOR]

A comparative experimental study on the heat transfer characteristics of steam and air flow in rectangular channels roughened with parallel ribs was conducted with the use of an infrared camera. The effects of Reynolds numbers ( Re ), rib spacing ratio ( P / e ) and rib angles ( α ) on steam and air convective heat transfer were obtained and compared. The blockage ratio ( e / D h ) of the tested channel is 0.078 and the aspect ratio ( W / H ) is fixed at 3.0. In the paper, the Reynolds number for both coolants ranges from 3000 to 15,000, the rib spacing ratios were 8, 10 and 12, and rib angles were 90°, 75°, 60°, and 45°, respectively. For a square channel with 90° ribs with wider rib spacing ratio ( P / e = 10 and 12) respectively give a area-averaged heat transfer about 8.4% and 11.4% more than P / e = 8 model. The heat transfer enhancement of both steam and air increased with decreasing the rib angle from 90° to 45°. Although the heat transfer distributions of steam and air flow in the rib roughness channels were similar to each other in all the investigated channels, the steam flow can obtain a high convective heat transfer enhancement capability. The area-averaged Nusselt numbers of steam flow at a Reynolds number of 12,000 were approximately 13.9%, 14.2%, 19.9%, and 23.9% higher than those of air flow for rib angles of 90°, 75°, 60°, and 45°, respectively. [ABSTRACT FROM AUTHOR]

Abstract: Lithium ion batteries are commonly employed in hybrid electric vehicles and achieving high energy density in the battery has been among the most critical issues in the automotive industry. Since thermal management is very important in the automotive batteries with layout limitation, a design strategy for effective cooling should be carefully opted. Particularly, a forced air cooling has been considered as a practical option in the automotive industry. In this article, a specific design of air-cooled battery system is theoretically investigated and numerically modelled to satisfy the required thermal specifications. Since a typical battery system in hybrid electric vehicles consists of the stacked multiple battery cells, cooling performance is determined mainly by the uniform distribution of air flow in the coolant passage which dissipates heat generated from the battery cells. It is demonstrated that the required cooling performance can be achieved by employing the tapered manifold and pressure relief ventilation even without changing the layout/design of the existing battery system. Furthermore, a theoretical analysis is performed as a design guideline to enhance the cooling performance. [Copyright &y& Elsevier]

The space scientific payload rack is a multifunctional experimental platform, and the requirements of the environmental temperature index are different for diversified experimental modules inside. The air cooling system is an important part of the rack thermal control system. A new type of air cooling system with small size and flexible arrangement is proposed in this paper, that is, micro air ducts with pinhole-sized air vents. The rack physical models of new and traditional air cooling modes are established, respectively. The numerical simulation of the inner air flow is carried out by Ansys Fluent CFD software (Ansys Inc., Canonsburg, PA, USA), which verifies that compared with the traditional method, the temperature field and flow field of the new air cooling method are more uniform, and the heat sources located at the edge of the rack can also be cooled better. [ABSTRACT FROM AUTHOR]