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Aerodynamic design and computational analysis of yaw sphere for subsonic wind tunnel

AIP Conference Proceedings 2020年第1期2311卷

作者： Akhila Rupesh J. V. Muruga Lal Jeyan 1PhD Scholar Department of Aerospace Engineering School of Mechanical Engineering Lovely Professional University India144111 2Professor Department of Aerospace Engineering School of Mechanical Engineering Lovely Professional University India144111

Flow analysis is considered to be the most crucial procedure in aerodynamics. Analysis of flow and its parameters over any object has to be done with considering aerodynamic loading acting over it. In the field of aerodynamics, wind tunnel test setup is used for flow analysis. The wind tunnel test section should always afford a laminar and uniform flow to provide exact results during flow parameter determination. But attaining cent percent laminar flow inside a wind tunnel test section is practically not possible. Hence there is an immense requirement of performing calibration before starting any research experiments in a wind tunnel. It is to be noted that wind tunnel calibration is done with ultimate care to avoid any error in the analysis. Generally a Pitot - static probe is used to calibrate subsonic wind tunnel. But the Pitot - static tube has many limitations like single point data sensing. Hence a new efficient and compact instrument has to be developed for the calibration of wind tunnels. In this paper, a yaw sphere is designed and analyzed to perform the calibration of a subsonic wind tunnel.

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Effect of Crystallinity on the Migration of Plastic Additives from Polylactic Acid-Based Food Contact Plastics

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SSRN 2022年

作者： Petrovics, Noémi Kirchkeszner, Csaba Patkó, Antónia Tábi, Tamás Magyar, Norbert Székely, Ilona Kovácsné Szabó, Bálint Sámuel Nyiri, Zoltán Eke, Zsuzsanna Hevesy György PhD School of Chemistry Eötvös Loránd University Pázmány Péter stny. 1/A BudapestH-1117 Hungary Joint Research and Training Laboratory on Separation Techniques Institute of Chemistry Eötvös Loránd University Pázmány Péter stny. 1/A BudapestH-1117 Hungary Department of Polymer Engineering Faculty of Mechanical Engineering Budapest University of Technology and Economics Műegyetem rkp. 3 BudapestH-1111 Hungary ELKH-BME Research Group for Composite Science and Technology Műegyetem rkp. 3 BudapestH-1111 Hungary Department of Methodology for Business Analyses Faculty of Commerce Hospitality and Tourism Budapest Business School Alkotmány u. 9–11 BudapestH-1054 Hungary Wessling International Research and Educational Center Anonymus u. 6 BudapestH-1045 Hungary

The dependence of swelling and migration on polymer crystallinity was investigated in the case of polylactic acid (PLA)-based plastics. Migration and swelling kinetic experiments were performed at two different temperatures, using plasticized/non-plasticized and annealed/unannealed PLA test *** swelling and migration proved to be inhibited by the presence of polymer crystals. Crystallization induced clear differences in migration at 40 °C contact temperature, which got more pronounced with the increasing molar weight (Mw) of additives. At 60 °C the differences diminished, except for Irgafos 168, possibly because of the formation of an inclusion complex type structure. Consequently, to lessen migration, the application of crystallized PLA and high Mw additives in food packaging industry is advantageous. The solvent-induced crystallization of PLA in ethanol 95 v/v% was also confirmed, therefore this alternative food simulant should be used only with restrictions in the migration testing of PLA-based plastics. © 2022, The Authors. All rights reserved.

关键词： Kinetics

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Development of the Gripper for the handwheel and the knob

Development of the Gripper for the handwheel and the knob

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International Conference on Ubiquitous Robots and Ambient Intelligence (URAI)

作者： Sucheol Lee Dongeun Choi Byungchul An Woosub Lee Division of Nano-Information Technology (HCI & Robotics) as a Master Candidate University of Science and Technology Daejeon Republic of Korea Department of Mechanical Engineering as Ph.D. Candidate Korea University Republic of Korea Center for Medical Robotics as a Post doctorial Researcher Korea Institute of Science and Technology Seoul Republic of Korea Center for Medical Robotics as a Principal Researcher and an Associate Professor of University of Science and Technology Korea Institute of Science and Technology Seoul Republic of Korea

ISBN: (数字)9781728157153

ISBN: (纸本)9781728157160

It is difficult for human beings to enter the dangerous terrain and to work there. In those places, robots work better than human beings do. To move into the place, the robots should have the appropriate gripper to unlock the door inside. In this paper, we have developed a robotic gripper that is able to hold a handwheel and a knob. This gripper is one degree of freedom system and compact design using lead screws but it has two motions such as the translational motion and the modified hyperbolic motion. Since the linkage of gripper has the translational motion in the axial direction, the gripper has much force than other grippers which are operated rotational direction. We have analyzed the geometric properties of the gripper to determine the optimal dimensions of the gripper link. Then, we present experimental results of sleeplessly opening doors with two handle types, such as a handwheel and a knob, using our novel gripper.

关键词： Grippers Robots Fasteners Lead Force Springs Pins

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Experimental Analysis of Aerodynamic Performance on asymmetric NACA 23018 Aerofoil incorporating a Leading-Edge Rotating Cylinder

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IOP Conference Series: Materials Science and engineering 2020年第4期912卷

作者： Md Abdus Salam MA Taher Ali Md Quamrul Islam PhD Student and Research Scholar Department of Mechanical Engineering Head Department of Aeronautical Engineering Military Institute of Science and echnology Bangladesh Professor Department of Aeronautical Engineering Military Institute of Science and Technology Bangladesh

The effects of Momentum Injection can play a vital role in increasing the efficiency of an aerofoil by increasing its lift and delaying the stall angle. Most of the studies regarding this concept analyzed the effects of momentum injection for higher velocity ratios (cylinder tangential velocity to free stream velocity) only. Almost no or less studies analyzed this effect for lower velocity ratios which created a research gap in this field. In this paper, a rotating cylinder is placed at the leading edge of an asymmetric aerofoil NACA 23018 and the aerodynamic performance with and without a rotating cylinder was studied for lower velocity ratios (<0.2). The experimental analysis was carried out for two Reynolds numbers (Re): 2 × 105 and 2.5 × 105 corresponding to two free stream velocities: 20 m/s and 25 m/s, respectively, for six different angles of attack (−5°, 0°, 5°, 10°, 15° and 20°). The experimental analysis showed that incorporating a leading-edge rotating cylinder increased the maximum lift coefficient by around 24% and delayed the stall angle by around 20%.

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Super Resolution for Improved Positioning of an MRI-Guided Spinal Cellular Injection Robot

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Journal of Medical Robotics Research 2021年第1-2期6卷

作者： Martinez, Daniel Enrique Meinhold, Waiman Oshinski, John Hu, Ai-Ping Ueda, Jun Robotics PhD Program Georgia Institute of Technology North Ave NW Atlanta 30332 GA United States Department of Radiology Emory University 201 Dowman Dr Atlanta 30322 GA United States Intelligent Sustainable Technologies Division Georgia Tech Research Institute 640 Strong Street Atlanta 30318 GA United States George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology North Ave NW Atlanta 30332 GA United States

This paper presents the development of a magnetic resonance imaging (MRI)-conditional needle positioning robot designed for spinal cellular injection. High-accuracy targeting performance is achieved by the combination of a high precision, parallel-plane, needle-orientation mechanism utilizing linear piezoelectric actuators with an iterative super-resolution (SR) visual navigation algorithm using multi-planar MR imaging. In previous work, the authors have developed an MRI conditional robot with positioning performance exceeding the standard resolution of MRI, rendering the MRI resolution the limit for navigation. This paper further explores the application of SR to images for robot guidance, evaluating positioning performance through simulations and experimentally in benchtop and MRI experiments. © 2021 World Scientific Publishing Company.

关键词： cellular therapeutics magnetic resonance imaging needle steering spinal cord Super resolution surgical robots visual robot guidance

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Identification of development of feasibility assessment for community based water power plant

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Journal of Physics: Conference Series 2020年第7期1477卷

作者： Suryadimal Ganefri Ambiyar Nizwardi Jalinus Fahmi Rizal Yeasy Darmayanti Department of Mechanical Engineering Faculty of Industrial Technology Universitas Bung Hatta Padang Indonesia and Phd Engineering Student Faculty Engineering Universitas Negeri Padang Indonesia Department of Electrical Engineering Faculty Engineering Universitas Negeri Padang Indonesia Department of Mechanical Engineering Faculty Engineering Universitas Negeri Padang Indonesia Department of Civil Engineering Faculty Engineering Universitas Negeri Padang Indonesia Department of Accountancy Faculty Bisnis and Economic Universitas Bung Hatta Padang Indonesia

This study aims to identify technical and non-technical aspects in developing the feasibility assessment of community-based *** technical aspects consist of the aspects of Hydrology, Civil and mechanical Electrical and non-technical aspects influenced by economic, socio-cultural and environmental aspects. In identifying the two aspects above exploration of Borg and Gall theory, and related studies in the feasibility assessment commonly used by a team of experts and technical consultants and government *** feasibility assessment is strongly influenced by 43.24% of technical and non-technical aspects, the relationship between hydraulics and economic aspects ranges 32.43%, and the influence of social and environmental aspects by 24.32%

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Drilling studies on Particle Board composite using HSS twist drill and spade drill

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Materials Today: Proceedings 2018年第8期5卷 16346-16351页

作者： A. Madhan Kumar K. Jayakumar Department of Mechanical Engineering New Prince Shri Bhavani College of Engineering and Technology Chennai - 600073 and PhD Scholar SSN College of Engg Chennai 603110 India Department of Mechanical Engineering SSN College of Engineering Chennai 603110 India

Composite materials are finding increased application in different engineering fields due to its favorable properties. In composites, wood based composites are natural composites in which particle board (PB) is extensively used in domestic and commercial purposes mainly in wood based furniture. Among different machining processes, drilling is the most generally used machining process in wood working industry for assembly operations. But during drilling, delamination at entry and exit sides of a hole, edge chipping, surface damage, etc are the major damages occur during drilling of PB composites. Therefore, study of effect of drilling parameters and cutting environment on machining of PB composite is an important area and it needs a detailed analysis. In this study, drilling of PB composite using HSS twist drill and spade drill of ∅ 10 mm is investigated. The objectives of the study are to measure and analyze the effect of process parameters on surface roughness and drilling time of PB for the two different drills. Process parameters considered are spindle speed (rpm), feed (mm/rev) and machining environment (Dry, Flood coolant and Kerosene). Drilling experiments were performed on 10 mm thickness board based on L 9 orthogonal array using twit drill and spade drill with the total of 18 experiments and average surface roughness (Ra) of all drilled holes surface was measured. From the results obtained with twist drill, machining time is decreased from 11.81 to 2.03 seconds with an increase of speed (S) and feed (f) for kerosene. Similarly, machining time is decreased from 18.54 to 2.97 sec with increase of “S” and “f” for the same kerosene with spade drill. With increase of “S” and “f” using kerosene, the Ra is decreased from 15.593 to 9.711 µm for twist drill. In the same way, the Ra is decreased from 15.3 to 10.083 µm with increase of “S” and “f” using kerosene for spade drill.

关键词： Drilling particle board composite coolant Surface roughness Machining Time HSS twist and Spade drill

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Computational analysis on hybrid composite material

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AIP Conference Proceedings 2020年第1期2311卷

作者： Sanjana Damodar Tulaskar Syed Shoeab Wazeer Poornachandra S. Goudar Abdul Rehaman Patel Akhila Rupesh UG Scholar Department of Aeronautical Engineering Mangalore Institute of Technology and Engineering Moodbidri 574225 India Assistant Professor Department of Aeronautical Engineering Mangalore Institute of Technology and Engineering Moodbidri 574225 India PhD Scholar Department of Aerospace Engineering School of Mechanical Engineering Lovely Professional University 144111 India

Present work describes an attempt to develop hybrid bio-composite material using Bombyx Silk & glass fiber reinforced in epoxy resin as matrix varying the orientation of silk fiber to the glass fiber at an angle of 90.˚ In medical industry weight is an important parameter that is considered widely in manufacturing of artificial limbs for physical disabled. Usually to support the person the structure needs enough strength to carry the weight of the person. The limb needs to be light in weight, so it should not affect the daily routine of the person. The structural member undergoes continuous cycles of compression and tension when the user is performing day to day activity. The procured materials were designed using COMSOL and different testing namely tensile, compression, flexure to be conducted on the samples

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Determination of Johnson Cook Material Model Constants for 93% WHA and Optimization using Genetic Algorithm

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Materials Today: Proceedings 2018年第9期5卷 18911-18919页

作者： Chithajalu Kiran Sagar Abhiram Chilukuri Amrita Priyadrashini PhD Scholar Mechanical Engineering Department BITS-Pilani Hyderabad campus Telangana 500078 India Student Mechanical Engineering Department BITS-Pilani Hyderabad campus Telangana 500078 India Assitant Professor Mechanical Engineering Department BITS-Pilani Hyderabad campus Telangana 500078 India

An accurate material constitutive model is a key concern to develop a realistic FE models both for machining as well as penetration mechanisms. A commonly used material model in both the cases is Johnson–Cook (JC) model which is generally available in most of the commercial FE codes. The constants of the JC constitutive model are generally determined by Split Hopkinson Pressure Bar (SPHB). In this paper, experimental SHPB test data taken from literature has been utilized to determine J-C model constants under wide range of strain rates and temperatures for 93% W Tungsten Heavy alloy (WHA). The calculated values of material model constants are then optimized using Evolutionary Algorithm based technique i.e. Genetic Algorithm (GA). The predicted results would help compare the efficiency of the optimization technique used in the present work for fine-tuning the JC model constants in terms of absolute error and coefficient of correlation. Furthermore, the predicted values of JC model constants can be appropriately used for FE simulations of both machining as well as penetration mechanisms for WHA alloys. The material taken into consideration for the present study finds application typically in armour piercing ammunition

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Kinetics and Isotherms of a Green Method for the Sorption of Metal Ions from Aqueous Solution

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IOP Conference Series: Materials Science and engineering 2020年第1期888卷

作者： H A Gzar K M Kseer M J Nasir Faculty member PhD Civil Engineering Department College of Engineering Wasit University Iraq. Faculty member MSc Mechanical Engineering Department College of Engineering Wasit University Iraq. Faculty member PhD Al-Mussaib Technical Institute Al-Furat Al-Awsat Technical University 51009 Babylon Iraq.

Owing to their toxicity, the existence of heavy metals in the environment has become a major global concern. In this study, the ability of albizia-lebbeck tree leaves (ALTL) as green and low cost adsorbent to remove Pb2+, Zn2+ and Cd2+ from Synthetic wastewater by adsorption was investigated. The initial metals' concentrations of 10-80 mg/l, adsorbent dosage of 0.3-1.0 gm, pH of 3-8, contact time of 30-240 min, and shaking speed of 200 rpm, have been studied by batch adsorption technique. Four ranges of adsorbent particle size were tested: 75-150; 150-300; 300-600; 600-1000 μm. Five different temperatures (20, 30, 40, 50 and 60°C) were selected to demonstrate the influence of temperature on metals' adsorption onto ALTL. Langmuir and Freundlich models were used to analyze the experimental data. Equilibrium data fitted well with the Freundlich isotherm model with maximum adsorption capacity of 9.124 mg/g at 20°C for metals' concentration of 40 mg/L. Pseudo-first-order and pseudo-second-order equations were utilized for analysis of the kinetic data. The second-order model was fitting very well with the experimental data. Thermodynamic parameters like entropy, enthalpy and Gibbs free energy changes were estimated to determine the spontaneity of the sorption process. The results revealed that the ALTL adsorbent performed good removal of metals.

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