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Computational Performance of a LES Solver for Supersonic Jet Flow Applications

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arXiv 2023年

作者： Junqueira-Junior, Carlos Azevedo, João Luiz F. Yamouni, Sami Wolf, William R. Instituto de Aeronáutica e Espaço SP São José dos Campos12228-904 Brazil Instituto Tecnológico de Aeronáutica SP São José dos Campos12228-900 Brazil Universidade Estadual de Campinas SP Campinas13083-970 Brazil Aerodynamics Division Departamento de Ciência e Tecnologia Aeroespacial DCTA/IAE/ALA Brazil Graduate Program on Computer Sciences and Electrical Engineering Departamento de Ciência e Tecnologia Aeroespacial DCTA/ITA Brazil Faculty of Mechanical Engineering

An in-house large eddy simulation tool is developed in order to reproduce high fidelity results of compressible jet flows. The large eddy simulation formulation is written using the finite difference approach, with an explicit time integration and using a second order spatial discretization. The energy equation is carefully discretized in order to model the energy equation of the filtered Navier-Stokes formulation. Such numerical studies are very expensive and demand high performance computing. Message passage interface protocols are implemented into the code in order to perform parallel computations. The present work addresses the computational performance of the solver running on up to 400 processors in parallel. Different mesh configurations, whose size varies from approximately 5.9 million points to approximately 1.0 billion points, are evaluate in the current paper. Speedup and efficiency curves are evaluated in order to assess the strong scalability of the solver. © 2023, CC BY.

关键词： Large eddy simulation

Influence of Different Subgrid Scale Models in LES of Supersonic Jet Flows

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arXiv 2023年

作者： Junqueira-Junior, Carlos Yamouni, Sami Azevedo, João Luiz F. Wolf, William R. Instituto de Aeronáutica e Espaço SP São José dos Campos12228-904 Brazil Instituto Tecnológico de Aeronáutica SP São José dos Campos12228-900 Brazil Universidade Estadual de Campinas SP Campinas13083-970 Brazil Aerodynamics Division Departamento de Ciência e Tecnologia Aeroespacial DCTA/IAE/ALA Brazil Graduate Program on Computer Sciences and Electrical Engineering Departamento de Ciência e Tecnologia Aeroespacial DCTA/ITA Brazil Faculty of Mechanical Engineering

Current design constraints have encouraged the studies of aeroacoustics fields around compressible jet flows. The present work addresses the numerical study of subgrid scale modeling for unsteady turbulent jet flows as a preliminary step for future aeroacoustic analyses of main engine rocket plumes. An in-house large eddy simulation (LES) tool is developed in order to reproduce high fidelity results of compressible jet flows. In the present study, perfectly expanded jets are considered because the authors want to emphasize the effects of the jet mixing phenomena. The large eddy simulation formulation is written using the finite difference approach, with an explicit time integration and using a second order spatial discretization. The energy equation is carefully discretized in order to model the energy equation of the filtered Navier-Stokes formulation. The classical Smagorinsky model, the dynamic Smagorinsky model and the Vreman models are the chosen subgrid scale closures for the present work. Numerical simulations of perfectly expanded jets are performed and compared with the literature in order to validate and compare the performance of each subgrid closure in the solver. © 2023, CC BY.

关键词： Large eddy simulation

Throughput estimation of slotted np-CSMA based on semi-Markov process 7

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Throughput estimation of slotted np-CSMA based on semi-Marko...

7th International electrical engineering Congress, iEECON 2019

作者： Saenmuang, Adisorn Sitjongsataporn, Suchada Electrical Engineering Graduate Program Faculty of Engineering Mahanakorn University of Technology 140 Cheumsamphan Rd. Nongchok Bangkok Thailand Faculty of Engineering Mahanakorn University of Technology 140 Cheumsamphan Rd. Nongchok Bangkok Thailand

ISBN: (纸本)9781728107295

Throughput estimation of slotted non-persistent carrier sense multiple access (slotted np-CSMA) protocol based on semi-Markov process is presented. CSMA protocol, a random access, which are used widely in different communication systems packets. In Radio Frequency Identification (RFID), most problems are caused by data collisions, therefore, to analyze the collisions and avoiding collision in RFID system. We propose the concept of slotted np-CSMA protocol by means of Poisson-based packet size by semi-Markov process in the RFID system. This paper presents the study about throughput performance of slotted np-CSMA systems for the offered traffic. Simulation results show that the performance of semi-Markov-based slotted np-CSMA can obtain the good performance related to lower propagation delay compared with Markov model. © 2019 IEEE.

关键词： Carrier sense multiple access

Topological solitonic macromolecules

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arXiv 2023年

作者： Zhao, Hanqing Malomed, Boris A. Smalyukh, Ivan I. Department of Physics University of Colorado BoulderCO80309 United States Department of Physical Electronics School of Electrical Engineering Faculty of Engineering Center for Light-Matter Interaction Tel Aviv University P.O.B. 39040 Ramat Aviv Tel Aviv Israel Instituto de Alta Investigación Universidad de Tarapacá Casilla 7D Arica Chile Materials Science and Engineering Program University of Colorado BoulderCO80309 United States International Institute for Sustainability with Knotted Chiral Meta Matter Hiroshima University Higashi Hiroshima Hiroshima739-8526 Japan Renewable and Sustainable Energy Institute National Renewable Energy Laboratory University of Colorado BoulderCO80309 United States

Being ubiquitous, solitons have particle-like properties, exhibiting behaviour often associated with atoms. Bound solitons emulate dynamics of molecules, though solitonic analogues of polymeric materials have not been considered yet. Here we experimentally create and model soliton polymers, which we call "polyskyrmionomers", built of atom-like individual solitons characterized by the topological invariant representing the skyrmion number. With the help of nonlinear optical imaging and numerical modelling based on minimizing the free energy, we reveal how topological point defects bind the solitonic quasi-atoms into polyskyrmionomers, featuring linear, branched, and other macromolecule-resembling architectures, as well as allowing for encoding data by spatial distributions of the skyrmion number. Application of oscillating electric fields activates diverse modes of locomotion and internal vibrations of these self-assembled soliton structures, which depend on symmetry of the solitonic macromolecules. Our findings suggest new designs of soliton meta matter, with a potential for the use in fundamental research and technology. © 2023, CC BY.

关键词： Macromolecules

A performance and efficiency comparison of an AFE rectifier with Finite Control Set – Model Predictive Control and Feedback Quantizer

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A performance and efficiency comparison of an AFE rectifier ...

CHILEAN Conference on electrical, Electronics engineering, Information and Communication Technologies (CHILECON)

作者： Jhon Henríquez Eduardo Espinosa Matías Veillon Hugo Garcés Pedro Melín Marcelo Reyes Carlos Baier Galina Mirzaeva Universidad Católica de la Santísima Concepción Concepción Chile Universidad del Bío-Bío Concepción Chile PhD Student Doctoral Program in Engineering at the MacroFacultad de Ingeniería UFRO-UBB-UTAL Chile Universidad de Talca Curicó Chile School of Electrical Engineering and Computing The University of Newcastle Callaghan NSW Australia

ISBN: (纸本)9781665408745

In this work, a comparative analysis of the performance and efficiency of the FCS-MPC and Modulation FBQ applied to an AFE active front rectifier is carried out. The above compares quality indicators of form in the input current of an AFE, THD, and WTHD rectifier. For efficiency, the conduction and commutation losses in the switches will be estimated to obtain a selection criterion between these two control methods, which will be based on the efficiency of the converter and the performance of the input current loop. The semiconductors losses are calculated by linear mathematical approximations, which depend on the operation point of the AFE rectifier and the switch parameters, which are obtained from the datasheet provided by the switch manufacturer, which for this work, IGBT IKW25T120 was selected. Finally, for the performance analysis, satisfactory simulation results were obtained.

关键词： Insulated gate bipolar transistors Simulation Conferences Rectifiers Modulation Control systems Performance analysis

Rabi antenna using microstrip add-drop multiplexer for electron warp speed investigation

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Chinese Optics Letters 2022年第7期20卷 80-87页

作者： Somchat Sonasang Prakasit Prabpal Piya Sirikan Pratimakorn Hakaew Nhat Truong Pham Preecha Yupapin Kanad Ray Sarawoot Boonkirdram Department of Electronic Technology Faculty of Industrial TechnologyNakhon Phanom UniversityNakhon Phanom 48000Thailand Department of Electrical Technology School of Industrial TechnologySakonnakhon Technical CollegeInstitute of Vocational Education Northeastern Region 2Sakonnakhorn 47000Thailand Division of Computational Mechatronics Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh City 72915Vietnam Faculty of Electrical and Electronics Engineering Ton Duc Thang UniversityHo Chi Minh City 72915Vietnam Amity School of Applied Sciences Amity University RajasthanJaipurIndia Faubert Lab Universitéde MontréalH3T 1P1 MontréalCanada Facultad de CienciasFisico-Matematicas Benemérita Universidad Autónoma de PueblaAv.San Claudio y Av.18 surCol.San Manuel Ciudad UniversitariaPuebla Pue 72570Mexico Program of Electrical and Electronics Faculty of Industrial TechnologySakon Nakhon Rajabhat UniversitySakon Nakhon 47000Thailand

This work presents experimental results of Rabi antenna characteristics using the coupled line microstrip *** was constructed by a modified coupled line microstrip four-port network,which is known as an add-drop *** driven AC input enters the device via an input port using the suitable frequency and coupled line microstrip ring *** multilevel system is generated by a wave-particle aspect before the two-level system is *** the resonance,the transitions of the states induce the energy called whispering gallery mode(WGM)at the circuit center,which is the squeezed *** generated electron oscillation within the WGM envelope oscillated by the frequency is known as the Rabi *** the successive filtering with continuous AC input via the selected port,the electron cloud warp speed can be generated and achieved inside the two-level *** constructed microstrip ring radius is 25 mm,and the experimental results of the Rabi antenna characteristics are in good agreement with the simulation *** obtained resonant antenna oscillation frequency is 2.103 *** electron cloud warp speed of 1.100c and time dilation of 0.006μs are obtained.

关键词： integrated photonics waveguide microwave photonics Rabi antenna

Reliability Analysis of IGBT Modules of Multilevel Inverters Operating in Hostile Environments

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Reliability Analysis of IGBT Modules of Multilevel Inverters...

Industrial Applications Society Annual Conference on Petroleum and Chemical Industry

作者： Caio Eduardo Silva Gabriela Lígia Reis André M. Alzamora Hélder de Paula Projects and Works Division (DPROB) Federal University of São João del-Rei (UFSJ) São João del-Rei MG Brazil Department of Education and Technology (DET) Federal Institute of Southeast Minas Gerais (IF Sudeste MG) Juiz de Fora MG Brazil Grad. Program in Elec. Eng. Federal University of Uberlândia (UFU) Uberlândia MG Brazil Electrical Engineering Faculty (FEELT) Federal University of Uberlândia (UFU) Uberlândia MG Brazil

ISBN: (数字)9798350353402

ISBN: (纸本)9798350353419

Throughout the industry, pulse width modulation voltage source inverters (PWM-VSI) are commonly utilized with adjustable speed drives (ASD) to control, most commonly, induction motors. Especially in the mining and petroleum industries, long cables connecting motors and inverters are often present, which can cause several problems. As an innovative solution, an alternative system configuration has been previously proposed, in which the rectifier is kept in its typical location, and the inverter bridge and DC bus capacitors are installed near the driven motor. Long cables are used as a DC transmission line, mitigating the high-frequency problems resulting from the inverter-cable-motor interaction. On the other hand, new concerns regarding the reliability of the power devices arise once the inverter is installed in harsh ambient conditions. In this context, this work proposes a reliability analysis of such drive configuration, applying the physics of failure (PoF) approach combined with the design for reliability (DfR) methodology to carry out the design adjustments to achieve the reliability required for the application, focusing on the inverter IGBT modules. Moreover, this paper will evaluate widely accepted multilevel inverter topologies and modulation strategies, verifying those capable of minimizing implementation costs and ensuring adequate reliability indexes for the system—aiming to enable the commercial use of this promising configuration. The results show that a three-level active neutral point clamped inverter (3L-ANPC) topology applying two pulse width modulation (PWM) strategies and 400 A – 6.5 kV IGBTs would be the most appropriate from this study's reliability and feasibility analyses.

关键词： Insulated gate bipolar transistors Commutation Voltage Pulse width modulation Reliability engineering Inverters Topology Power system reliability Reliability Cables

A simple approach for curcumin extraction from turmeric roots

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AIP Conference Proceedings 2022年第1期2537卷 040016页

作者： Siti Fauziyah Rahman Adella Josephin Ridha Alviny Syakirah Grace Priscilla Nadia Wulandari Nurul Intan Yudan Whulanza Biomedical Engineering Study Program Department of Electrical Engineering Faculty of Engineering Universitas Indonesia Kampus UI Depok West Java 16424 Indonesia Research Center for Biomedical Engineering Faculty of Engineering Universitas Indonesia Kampus UI Depok West Java 16424 Indonesia Department of Mechanical Engineering Faculty of Engineering Universitas Indonesia Kampus UI Depok West Java 16424 Indonesia

Turmeric, particularly its most active ingredient, curcumin, has a long list of scientifically documented health advantages, including the ability to boost heart health and protect against a variety of diseases. Curcumin is one of the most important active components in turmeric, with a wide range of bioactivity and medicinal uses. Preparing samples from biological components is a time-consuming and difficult operation. This study aims to understand the process of extracting curcumin from turmeric and to analyze the appropriate solvent for curcumin extraction. The method used is Soxhlet extraction with acetone and ethanol as solvents. The analysis of curcumin content was carried out using a UV-Vis spectrophotometer. The results showed that the curcumin extracted with acetone solvent had a higher concentration than the extraction with ethanol. Therefore, extracting curcumin from turmeric using the Soxhlet method, acetone is a superior solvent than ethanol.

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Revealing preference in popular music through familiarity and brain response

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arXiv 2021年

作者： Sangnark, Soravitt Autthasan, Phairot Ponglertnapakorn, Puntawat Chalekarn, Phudit Sudhawiyangkul, Thapanun Trakulruangroj, Manatsanan Songsermsawad, Sarita Assabumrungrat, Rawin Amplod, Supalak Ounjai, Kajornvut Wilaiprasitporn, Theerawit Bio-inspired Robotics and Neural Engineering Lab. School of Information Science and Technology Vidyasirimedhi Institute of Science & Technology Rayong Thailand Vision and Learning Lab. School of Information Science and Technology Vidyasirimedhi Institute of Science & Technology Rayong Thailand School of Energy Science and Engineering Vidyasirimedhi Institute of Science & Technology Rayong Thailand Biological Engineering program Faculty of Engineering Neuroscience Center for Research and Innovation Learning Institute King Mongkut’s University of Technology Thonburi Thailand Faculty of Electrical Engineering Sirindhorn International Institute of Technology Thammasat University Thailand School of Engineering Tohoku University Japan

Music preference was reported as a factor, which could elicit innermost music emotion, entailing accurate ground-truth data and music therapy efficiency. This study executes statistical analysis to investigate the distinction of music preference through familiarity scores, response times (response rates), and brain response (EEG). Twenty participants did self-assessment after listening to two types of popular music’s chorus section: music without lyrics (Melody) and music with lyrics (Song). We then conduct a music preference classification using a support vector machine, random forest, and k-nearest neighbors with the familiarity scores, the response rates, and EEG as the feature vectors. The statistical analysis and F1-score of EEG are congruent, which is the brain’s right side outperformed its left side in classification performance. Finally, these behavioral and brain studies support that preference, familiarity, and response rates can contribute to the music emotion experiment’s design to understand music, emotion, and listener. Not only to the music industry, the biomedical and healthcare industry can also exploit this experiment to collect data from patients to improve the efficiency of healing by music. © 2021, CC BY-NC-ND.

关键词： Decision trees