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Mosfequr Rahman

Bio: Mosfequr Rahman is an academic researcher from Georgia Southern University. The author has contributed to research in topics: Turbine & Wind power. The author has an hindex of 7, co-authored 44 publications receiving 173 citations.

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TL;DR: In this article, a series of wind tunnel investigations on semi-cylindrical three-bladed Savonius rotor scale models with different overlap ratios and without overlap were conducted in front of a low-speed subsonic wind tunnel at different Reynolds numbers.
Abstract: The purpose of this research work is to investigate experimentally and computationally the feasibility of improving the performance of the vertical-axis Savonius wind turbine. The authors first performed a series of wind tunnel investigations on semi-cylindrical three-bladed Savonius rotor scale models with different overlap ratios and without overlap. These experiments were conducted in front of a low-speed subsonic wind tunnel at different Reynolds numbers. Pressures around the concave and convex surfaces of each blade, as well as the static torque for the rotor models, were measured. Using these experimental data, the authors calculated aerodynamic characteristics such as drag coefficients, static torque coefficients, and power coefficients. The authors then performed computational fluid dynamics (CFD) simulations using the commercial CFD software FLUENT and GAMBIT to analyze the static rotor aerodynamics of those models. The experimental and computational results were then compared for verification. Three different models with different overlap ratios were designed and fabricated for the current study to find the effect of overlap ratios. The results from the experimental part of the research show a significant effect of overlap ratio and Reynolds number on the improvement of aerodynamic performance of the Savonius wind turbine. At higher Reynolds number, the turbine model without overlap ratio gives better aerodynamic coefficients, and at lower Reynolds number, the model with moderate overlap ratio gives better results.

52 citations

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TL;DR: Various wireless power transfer (WPT) methods for electric vehicles charging are conferred in brief with some scientific examples and approaches.

41 citations

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TL;DR: In this paper, the effects of nanofluid impingement on cooling-system materials are investigated using roughness measurements and optical-microscope studies, and the possible mechanisms of early erosion are discussed.
Abstract: Nanofluids are nanosize-powder suspensions that are of interest for their enhanced thermal transport properties. They are studied as promising alternatives to ordinary cooling fluids, but the tribiological effects of nanofluids on cooling-system materials are largely unknown. The authors have developed methodology that uses jet impingement on typical cooling-system materials to test such effects. The work is presented of the authors’ research on the interactions of a typical nanofluid (2% volume of alumina nanopowders in a solution of ethylene glycol in water) which is impinged on aluminum and copper specimens for tests as long as 112 hours. The surface changes were assessed by roughness measurements and optical-microscope studies. Comparative roughness indicate that both the reference cooling fluid of ethylene glycol and water and its nanofluid with 2% alumina produce roughness changes in aluminum (even for the shortest 3-hour test), but no significant roughness differences were observed between them. No significant roughness changes were observed for copper. Microscopy observations, however, show different surface modifications in both aluminum and copper by both the nanofluid and its base fluid. The possible mechanisms of early erosion are discussed. These investigations demonstrate suitable methods for the testing of nanofluid effects on cooling system-materials.

19 citations

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TL;DR: In this article, a finite element model was developed and analyzed to study the feasibility of photostrictively driven actuators for excitation of microbeams, and the effect of different parameters such as actuator thickness, incident light intensity, and convective heat transfer coefficient on the actuation of a beam using thin film photostrictionive actuators has been investigated.
Abstract: Photostriction is a phenomenon in which strain is induced in the sample by incident light. In principle, this effect arises from a superposition of the photovoltaic effect, i.e. the generation of large voltage from the irradiation of light, and the converse piezoelectric effect, i.e. expansion or contraction under the voltage applied. Photostrictive materials are ferrodielectric ceramics that have a photostrictive effect. Some photostrictive materials are (Pb, La)(Zr, Ti) O3 ceramics doped with WO3, called PLZT, which exhibit large photostriction under uniform illumination with high-energy light. They have potential use in numerous micro-electro-mechanical system (MEMS) devices where actuation of microbeams is a common phenomenon. The objective of this research is to develop and analyze a finite element model to study the feasibility of photostrictively driven actuators for excitation of microdevices. Much work has been carried out toward developing microdevices which are capacitively driven or piezoelectrically driven. The effect of different parameters such as actuator thickness, incident light intensity and convective heat transfer coefficient on the actuation of a beam using thin film photostrictive actuators has been investigated. Also the derived finite element for static analysis of photostrictive thin films has been used to investigate the application of photostrictive actuators for different structures and various boundary conditions of microbeams with various actuator locations and lengths. A successful conclusion of these tasks will affirm the potential of the technology for use in actual microdevices.

16 citations

Journal ArticleDOI
01 May 2020-Energy
TL;DR: In this article, the authors investigate the correlation between thermal characteristics of neat Iso-Paraffinic Kerosene (IPK) in relation to Low Temperature Heat Release (LTHR), ignition delay, and combustion delay within the Negative Temperature Coefficient region (NTC), utilizing a Box-Behnken design matrix.

12 citations


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TL;DR: A review of the progress made in the area of nanofluids preparation and applications in various heat transfer devices such as solar collectors, heat exchangers, refrigeration systems, radiators, thermal storage systems and electronic cooling is presented in this paper.
Abstract: The field of nanofluids has received interesting attention since the concept of dispersing nanoscaled particles into a fluid was first introduced in the later part of the twentieth century This is evident from the increased number of studies related to nanofluids published annually The increasing attention on nanofluids is primarily due to their enhanced thermophysical properties and their ability to be incorporated into a wide range of thermal applications ranging from enhancing the effectiveness of heat exchangers used in industries to solar energy harvesting for renewable energy production Owing to the increasing number of studies relating to nanofluids, there is a need for a holistic review of the progress and steps taken in 2019 concerning their application in heat transfer devices This review takes a retrospective look at the year 2019 by reviewing the progress made in the area of nanofluids preparation and the applications of nanofluids in various heat transfer devices such as solar collectors, heat exchangers, refrigeration systems, radiators, thermal storage systems and electronic cooling This review aims to update readers on recent progress while also highlighting the challenges and future of nanofluids as the next-generation heat transfer fluids Finally, a conclusion on the merits and demerits of nanofluids is presented along with recommendations for future studies that would mobilise the rapid commercialisation of nanofluids

181 citations

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TL;DR: In this paper, the link between the aspect ratio of a vertical-axis straight-bladed (H-Rotor) wind turbine and its performance (power coefficient) was analyzed.
Abstract: This work analyses the link between the aspect ratio of a vertical-axis straight-bladed (H-Rotor) wind turbine and its performance (power coefficient). The aspect ratio of this particular wind turbine is defined as the ratio between blade length and rotor radius. Since the aspect ratio variations of a vertical-axis wind turbine cause Reynolds number variations, any changes in the power coefficient can also be studied to derive how aspect ratio variations affect turbine performance. Using a calculation code based on the Multiple Stream Tube Model, symmetrical straight-bladed wind turbine performance was evaluated as aspect ratio varied. This numerical analysis highlighted how turbine performance is strongly influenced by the Reynolds number of the rotor blade. From a geometrical point of view, as aspect ratio falls, the Reynolds number rises which improves wind turbine performance.

143 citations

Journal ArticleDOI
TL;DR: In this paper, a photovoltaic thermal collector was constructed by laminating a copper sheet directly to the silicon cell, thereby reducing the thermal resistance and its performance was improved by using copper oxide -water (CuO/H 2 O) nanofluid.

128 citations

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TL;DR: A prototypal system for the dynamic inductive power transmission whose goal is to extend the battery range by a fast partial recharging during the movement of the vehicle is described.
Abstract: The paper discusses the development status of the inductive power transmission for automotive applications. This technology is, in fact, gaining the interest of electric vehicle manufacturers as an effective strategy to improve the market penetration of electric mobility. Starting from the origin of this technology, the paper presents an overview of the current state of the art as well as the current research and industrial projects. Particular attention is devoted to the description of a prototypal system for the dynamic inductive power transmission whose goal is to extend the battery range by a fast partial recharging during the movement of the vehicle.

111 citations

Journal ArticleDOI
TL;DR: In this paper, the effect of temperature on PV electrical efficiency, construction of Photovoltaic-Thermal (PV/T) module, historical development of PV/T, about different types of PV and thermal modules developed around the globe along with performance of developed PV/Ts, effect of operating parameters and methods of thermodynamic management are reviewed and presented.
Abstract: Carbon dioxide emissions from burning fossil fuels are believed to be the main factor for alarming rise in global temperatures. Conference of Parties 21 held at Paris in the year 2015 strictly warned and asked the nations to reduce their greenhouse gas emission level. This makes the nations to adopt renewable energy technology to substitute burning fossil fuels. Solar energy due to its accessibility and affordability leads the renewable energy application race. Even though Photovoltaic (PV) technology is mature but the effect of temperature on its efficiency is considerable, which opens up new front of research where combination of PV and thermal absorber is focussed to harness thermal energy which otherwise negatively affect the PV electrical efficiency. In the proposed study starting from the effect temperature on PV electrical efficiency, construction of Photovoltaic-Thermal (PV/T) module, historical development of PV/T, about different types of PV/T's developed around the globe along with performance of developed PV/T's, effect of operating parameters and methods of thermodynamic management are reviewed and presented. The study emphasised on the use of nano fluid and phase change material to harness maximum thermal energy from the system, also includes an insight into commercially available PV/T modules across the globe. This paper presents enviro-economic evaluation of PV/T systems developed by various researchers and also enumerated thermodynamic methods for evaluating system efficiency, which includes both energy and exergy analysis. This paper also provides the necessary information about the requirement of future research in PV/T.

110 citations