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Brownian motion effects and thermophoresis on heat transmission mechanism of hybrid nano liquid flow over a stretched wedge surface
(2025-06-01)
Swami, Sharanayya
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Biradar, Suresh
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Tawade, Jagadish V.
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Govindan, Vediyappan
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Byeon, Haewon
The current study observes the impact of thermophoresis, Brownian motion, and magnetic fields on the flow and heat transfer properties of a hybrid nanofluid containing Al<inf>2</inf>O<inf>3</inf>, CuO, and ethylene glycol over a wedge-shaped surface undergoing horizontal stretching. The study addresses the critical need to enhance energy transfer and thermal management systems, which have significant technical and industrial applications. To model the problem, flow equations were transformed into ordinary differential equations using similarity transformations and solved numerically via the Runge-Kutta-Fehlberg method. The results reveal that the wedge angle and magnetic field strength are crucial factors influencing the flow and thermal behavior. Specifically, increasing the wedge angle enhances the Nusselt number but reduces the thermal and diffusion profiles. The suction and injection of the fluid significantly impact the local heat transfer rates and boundary layer thickness. Additionally, the Buongiorno slip parameter reduces the rate of energy transfer while amplifying thermal distributions. The thermophoresis parameter was found to influence both concentration and thermal boundary layers. A comparative analysis between Newtonian and non-Newtonian fluids showed that hybrid nanofluids improve mass and energy transfer rates in both cases, with enhanced effects observed in non-Newtonian fluids. The study's novelty lies in its comprehensive exploration of magneto-flow dynamics and hybrid nanofluid behavior in the context of wedge geometries and external magnetic fields. The findings extend previous research by offering quantitative insights into how key parameters like wedge angles, thermophoresis, and Brownian motion affect heat and mass transfer processes, providing a robust framework for optimizing hybrid nanofluid applications in engineering and industrial systems. The results align well with existing literature, validating the study's contributions to the field.
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Research of Magnetic and Electric Fields to Design and Develop the Prototype of Magnetic Resonance Imaging Device
(2025-01-01)
Chompoo-Inwai, Chai
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Chompoo-Inwai, Chow
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Suksathit, Witchayaphorn
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Kaewpromrat, Weerapat
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Maneerat, Saranyu
This research presents a study and preliminary design of a main magnetic field generation system for an MRI machine using simulation software. The objective is to investigate the factors affecting magnetic field strength. Six coil models were preliminarily designed and simulated to analyze the magnetic field behavior. Simulation results were compared with experimental magnetic field measurements, showing that the software accurately reproduces the magnetic field. It was found that distributed winding improves field uniformity, and that both the number of coil turns and conductor size directly affect the strength of the main magnetic field in the air core.Based on the simulation outcomes, a prototype magnetic field generation system was designed. The proposed prototype consists of an aluminum core with a diameter of 110 mm and a height of 335 mm, suitable for arm imaging. The system uses a superconducting NbTi wire wound 6,516 turns in eight segments, with a current of 120 A. Cooling is achieved using a cryocooler model RDE-418D4 4K, which can reach temperatures as low as 4.2 K. This study provides essential guidance for the development of main magnetic field systems in future MRI devices.
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Magnetic and ultrasonic integrated photocatalytic hydrogen evolution effects with Nanosize CoOCu2OZnO and TiO2 decorated on reduced graphene oxide
(2023-12-01)
Areerob, Yonrapach
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Meng, Zeda
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Ullah, Kefayat
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Wijaya, Karna
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Otgonbayar, Zambaga
In this study, metal oxide composite (CoOCu<inf>2</inf>OZnO) and TiO<inf>2</inf> on graphene oxide composite (CCZ−G−T) were synthesized to improve visible light-driven H<inf>2</inf> evolution through the addition of a cation scavenger, ultrasonic effect, and magnetic field effect. The synthesized nanocomposites were characterized through structural, surface, and electrochemical analyses with band structure. The photocatalyst showed hydrogen production of 792 μmol·g−1 for 4 hours. Moreover, this CCZ−G−T photocatalyst exhibits relatively high photocatalytic activity at (530−810) μmol·g−1 when using a scavenger, 1,190 μmol·g−1 when using a magnetic field of 0.14 T, and 1,230 μmol·g−1 when using ultrasonic waves. The CCZ−G−T composite exhibited 630 μmol·g−1 under a magnetic field condition of 0.14 T for 1 hour, which was significantly higher than the hydrogen production rate of 510 μmol·g−1 under ultrasonic conditions. The current study provides new insights into the magnetic field effect on the hydrogen evolution reaction (HER) of graphene-based photocatalysts.
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Analysis Of Mutual Inductance Between Transmitter And Receiver Coils In Wireless Power Transfer System Of Electric Vehicle
(2023-01-01)
Zheng, Junlong
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Jettanasen, Chaiyan
In the electric vehicle wireless power transfer (WPT) system, the mutual inductance (M) between the transmitting and receiving coils is an important factor influencing overall system efficiency. The M is affected by various factors such as the physical structure of the coils diagram, the distance and relative position between the transmitting and receiving coils, and so on. Our work here has two outstanding contributions. First, the detailed mathematical model of the M was developed. Second, the three-dimensional spatial distribution diagram of the M was drawn using Python software, the maximum value of the M and its corresponding position coordinates were calculated. Then, the theoretical analysis of the M distribution was proven correct through experiments. The theoretical analysis and experimental verification of the M distribution provided a theoretical reference for the positioning requirements between the transmitting and receiving coils.in the electric vehicle WPT system.
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Measurement of metal particles in oil lubricant using hall effect sensor under temperature conditions
(2017-11-10)
Inthawatkul, Itti
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Sriratana, Witsarut
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Satthamsakul, Sutham
This paper develops a Hall-Effect sensor based system to assess the performance of a lubricant. The measurement methodology is based on the fact that the electromagnetically induced voltage is directly proportional to the amount of contaminants, which in turn affects the state of the lubricant. Two main cases are considered: the metal particles contaminant, and viscosity. The sample lubricant viscosity was experimentally found to be 49.2874 Cst, which is well within the range of internationally accepted values. Furthermore, the lubricant flow rate was also found to be temperature dependent. The output Hall voltage for the contaminated lubricant was 0.8 A for liquid flow rates between 0 to 30 l/h, which significantly deviates from the non-contaminated lubricant. These results suggests that the presented approach is a simple, low cost system capable of accurately assessing the performance of lubricants without consulting the manufacturer's information, even under normal operational loading.
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