GCRIS Repository Collection: Colleciton of Mechanical Engineering / Makina Mühendisliği Bölümü koleksiyonu
https://hdl.handle.net/11147/4129
Colleciton of Mechanical Engineering / Makina Mühendisliği Bölümü koleksiyonu
2024-03-27T12:08:16Z
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Energy and exergy analysis of a roof-mounted photovoltaic system in Gebze-Turkey
https://hdl.handle.net/11147/14197
Title: Energy and exergy analysis of a roof-mounted photovoltaic system in Gebze-Turkey
Authors: Khalejan, Seyed Hamed Pour Rahmati; Cankurt, Tolga; Dede, Mehmet İsmet Can
Abstract: This study investigates the electrical and thermal exergy, power conversion efficiency and exergy efficiency of a roof-mounted photovoltaic (PV) system considering environmental parameters such as solar irradiation, ambient temperature and wind speed over a year. The values of solar exergy and solar potential are obtained by taking into account the solar insolation. Experimental and theoretical results indicate that wind speed and surface temperature have significant effects on the thermal exergy and exergy efficiency of solar PV systems. The mean solar potential in the region was found to be 93%. In addition, the electrical exergy was varied from 9145 W to 40460 W and the thermal exergy of PV systems was varied from 1639 W to 6193 W. While the range of PV power conversion efficiency varies from 6.15% to 11.56% over a year, the range of exergy efficiency varies from 5.31% to 9.78%. © 2024, The Author(s), under exclusive license to Springer Nature Switzerland AG.
Description: 16th International Federation of Theory of Machines and Mechanisms World Congress, IFToMM WC 2023 -- 5 November 2023 through 9 November 2023
2024-01-01T00:00:00Z
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The design and kinematic representation of a soft robot in a simulation environment
https://hdl.handle.net/11147/14167
Title: The design and kinematic representation of a soft robot in a simulation environment
Authors: Emet, Hazal; Gür, Berke; Dede, Mehmet İsmet Can
Abstract: The increase of human presence in the subsea and seabed environments necessitates the development of more capable and highly dexterous, innovative underwater manipulators. Biomimetic soft-robot arms represent a promising candidate for such manipulation systems. However, the well-known modeling techniques and control theories of traditional rigid robots do not apply to soft robots. The challenges of kinematic and dynamic modeling of soft robots with infinite degrees of freedom require the development of dedicated modeling methods. A novel procedure for representing soft-robotic arms and their motion in a rigid-body simulation environment is proposed in this paper. The proposed procedure relies on the piecewise constant curvature approach to simplify the very complex model of hyper-redundant soft-robotic arms, making it suitable for real-time applications. The proposed method is implemented and verified to be used in model-mediated teleoperation of the soft arms of a biomimetic robotic squid designed for underwater manipulation as a case study. © 2023 The Author(s). Published by Cambridge University Press.
2024-01-01T00:00:00Z
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Four-bar function generation using excel solver
https://hdl.handle.net/11147/14065
Title: Four-bar function generation using excel solver
Authors: Söylemez, Eres; Kiper, Gökhan
Abstract: The Chapter presents a simple and efficient way of approximating a function with a four-bar mechanism using four or five design parameters including one or both of the initial crank angles. The method only involves solution of linear set of equations and evaluating determinants, whereas nonlinear equations are numerically solved using a simple program such as Excel. So, the method is easy to explain and can be taught in an undergraduate course along with the wellknown linear three precision point synthesis problem. Precision point synthesis, order synthesis, mixed order synthesis, least squares approximation and extreme point synthesis can all be treated using the same method. The proposed method is illustrated with numerical examples for all mentioned synthesis problems and shown to be quite efficient with very low amount of structural error values.
Description: The 16th IFToMM World Congress (IFToMM WC 2023), Nov 05-07, 2023, Tokyo, Japan
2023-01-01T00:00:00Z
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Cold plate enabling air and liquid cooling simultaneously: Experimental study for battery pack thermal management and electronic cooling
https://hdl.handle.net/11147/13989
Title: Cold plate enabling air and liquid cooling simultaneously: Experimental study for battery pack thermal management and electronic cooling
Authors: Coşkun, Turgay; Çetkin, Erdal
Abstract: The temperature of cells varies greatly during dis/charge while their performance and lifetime are greatly affected by this fluctuation. Elevated temperatures may yield battery fire due to thermal runaway as well they accelerate ageing and capacity fade of cells. Thermal management systems are a necessity for electric vehicles to extend the lifetime of battery cells and eliminate any fire risks, especially for fast dis/charging applications. Here, we document a hybrid cold plate with a working fluid(s) of sole air or liquid as well as both of them. Hybridization of air and liquid cooling promises to minimize energy consumption requirements during a charge/ discharge cycle by combining the benefits of both thermal management strategies if energy management is controlled accordingly. The temperature of each cell can be kept below 30 degrees C with the proposed hybrid cooling heat exchanger, and the temperature difference between the cells is reduced by 30 % relative to liquid cooling. The maximum temperatures are decreased by 18 % and 3 % in hybrid cooling when compared to air and water cooling, respectively. Furthermore, a step function combining various discharge rates (1C and 3C) was employed in experiments to mimic a realistic situation, i.e. variable C-rate rather than constant. The results show that the temperature of the battery cells can be kept below 30 degrees C with air cooling for variable discharge rate and the effect of contact resistance should not be overlooked for liquid cooling. Furthermore, the possible use of the proposed hybrid cold plates is surveyed in the cooling of electronic devices which produce more and continuous heat than cells. Therefore, three resistance heaters with a capacity of 50W are used in experiments as well. The results show that the proposed cold plates could be used in both electronics cooling and battery thermal management with a control algorithm to switch between sole working fluid and combination modes which could be developed based on the results of this paper.
2023-01-01T00:00:00Z