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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Air Recirculation System for Electrolyte Filling Room : A CFD study of VOCs Distribution in Clean & Dry room

Chen, Lin January 2022 (has links)
Energy storage development is an important step for the energy transition, meanwhile Lithium-ion battery is the most common core component of electric vehicles. Over the past decade, investment has been poured into lithium-ion battery production, as a result, the production environment (Clean & Dry room) used for some processes such as Stacking, Electrolyte filling and so on and the energy consumption to maintain this special environment which precise control of air humidity and air cleanliness have become major concerns. In this study, only one production process is concerned: electrolyte filling. During this process, Volatile Organic Compounds(VOCs) are the substance that affects air quality, also it is the reason that no air recovery in this Clean&Dry room before investigating the air quality, which leads to huge energy consumption for treating 100% fresh air.  The main purpose of this thesis is studying the Volatile Organic Compounds(VOCs) distribution in the Clean&Dry room with electrolyte filling activity to check whether the air quality is good enough to be recycled. This part of the study was approached by combining ANSYS FLUENT and the onsite measurement. A secondary objective is studying the energy-saving of dehumidification system with air recirculation system, meanwhile do the environmental analysis and cost analysis. In the end, in order to safely recycle the air in the Clean&Dry room, the Building Automation System should be installed solve the worst case scenario. The conclusions drawn in this study include the Electrolyte Filling machine forms a ”negative pressure room” which means the Volatile Organic Compounds(VOCs) generated from the machine is not likely spreading to the room, and the energy-saving, carbon footprint decreasing, energy cost and the cost of Building Automation System were provided. / Utveckling av energilagring är ett viktigt steg för energiomställningen, samtidigt är litiumjonbatterier den vanligaste nyckelkomponenten i elfordon. Under det senaste decenniet har investeringar gjorts i produktion av litiumjonbatterier, som ett resultat av produktionsmiljön (Rent & torrt rum) som används för vissa processer som stapling, elektrolytfyllning och så vidare och energiförbrukningen för att upprätthålla denna speciell miljö där exakt kontroll av luftfuktighet och luftrenhet har blivit ett stort problem. I denna studie berörs endast en produktionsprocess: elektrolytfyllning. Under denna process är flyktiga organiska föreningar (VOC) ämnet som påverkar luftkvaliteten, vilket också är anledningen till att ingen luftåtervinning i detta rena&torra rum innan man undersöker luftkvaliteten, vilket leder till enorm energiförbrukning för behandling av 100% frisk luft.  Huvudsyftet med denna avhandling är att studera distributionen av flyktiga organiska föreningar (VOC) i Clean&Dry-rummet med elektrolytfyllningsaktivitet för att kontrollera om luftkvaliteten är tillräckligt bra för att kunna återvinnas. Denna del av studien togs fram genom att kombinera ANSYS FLUENT och mätningen på plats. Ett sekundärt mål är att studera energibesparing av avfuktningssystem med luftcirkulationssystem, samtidigt gjorde miljöanalys och kostnadsanalys. I slutändan, för att säkert återvinna luften i Clean&Dry-rummet, bör Building Automation System implementeras för att lösa det värsta scenariot. Slutsatserna som dras i den här studien inkluderar att elektrolytfyllningsmaskinen bildar ett ”negativt tryckrum” vilket betyder att de flyktiga organiska föreningarna (VOC) som genereras från maskinen sannolikt inte sprider sig till rummet, och det energibesparande, koldioxidavtrycket minskar, energi kostnaden och kostnaden för Building Automation System tillhandahölls.
42

Level Up CFD - GPU-Beschleunigung in Ansys Fluent

Findeisen, Fabian 20 June 2024 (has links)
In der numerischen Strömungssimulation (Computational Fluid Dynamics, CFD) stellt die Berechnungsgeschwindigkeit einen kritischen Faktor dar. Insbesondere bei transienten Berechnungen oder bei der Simulation von umfangreichen Modellen können Berechnungen auf Hochleistungsrechnern mit mehreren hundert Kernen schnell zu einer zeitintensiven Aufgabe werden, die Tage oder sogar Wochen in Anspruch nimmt. Der Vortrag bietet einen detaillierten Einblick in die Möglichkeiten der GPU-Beschleunigung in Ansys Fluent und beleuchtet das Potenzial dieser innovativen Technologie. Zu Beginn wird der neue GPU-Solver in Ansys Fluent vorgestellt. Dieser Gleichungslöser nutzt die Rechenkapazität von Grafikprozessoren (GPUs), um CFD-Berechnungen durch extreme Parallelisierung effizienter durchzuführen als herkömmliche CPU-basierte Solver. Ein zusätzlicher Vorteil dieser Methode ist die signifikante Reduzierung des Energieverbrauchs und der Hardware-Investitionskosten. Im Anschluss werden Benchmarks von CPU- gegenüber GPU-basierten Lösungen anhand verschiedener Anwendungsfälle präsentiert. Diese Benchmarks verdeutlichen die Leistungsfähigkeit und Effizienz von GPU-Solvern im Vergleich zu CPU-Solvern. So kann beispielsweise die Außenumströmung eines Fahrzeugs mit dem Coupled GPU Solver zehnmal schneller auf einer Nvidia A100 GPU berechnet werden als auf herkömmlicher HPC-Hardware mit 48 Kernen. Der Vortrag bietet auch einen Überblick über den aktuellen Funktionsumfang und die zukünftige Entwicklungsroadmap von Ansys Fluent. Dies gibt einen Einblick in die aktuellen Funktionen des Tools und die geplanten Entwicklungen für die Zukunft. Ein weiterer wichtiger Aspekt sind die Lizenz- und Hardwareanforderungen. Dies hilft, die notwendigen Ressourcen für die Implementierung dieser Technologie in eigenen Projekten zu verstehen. Abschließend bietet der Vortrag einen Ausblick auf die Anwendung von Künstlicher Intelligenz (KI) für CFD. Mit der fortschreitenden Entwicklung der KI-Technologie eröffnen sich neue Möglichkeiten für die Verbesserung und Beschleunigung von CFD-Berechnungen. Insgesamt bietet der Vortrag einen umfassenden Überblick über die Anwendung von GPU-Beschleunigung in moderner CFD-Software und die zukünftigen Entwicklungen in diesem Bereich. / Calculation speed is a critical factor in computational fluid dynamics (CFD). Especially for transient calculations or the simulation of extensive models, calculations on high-performance computers with several hundred cores can quickly become a time-consuming task that takes days or even weeks. The presentation offers a detailed insight into the possibilities of GPU acceleration in Ansys Fluent and highlights the potential of this innovative technology. At the beginning, the new GPU solver in Ansys Fluent will be introduced. This solver uses the computing power of graphics processing units (GPUs) to perform CFD calculations more efficiently than conventional CPU-based solvers through extreme parallelization. An additional advantage of this method is the significant reduction in energy consumption and hardware investment costs. Subsequently, benchmarks of CPU- versus GPU-based solutions will be presented based on different use cases. These benchmarks illustrate the performance and efficiency of GPU solvers compared to CPU solvers. For example, the external airflow of a vehicle can be calculated ten times faster with the Coupled GPU Solver on an Nvidia A100 GPU than on conventional HPC hardware with 48 cores. The presentation will also provide an overview of the current range of functions and the future development roadmap.
43

Numerical Investigation of Flow Around a Deformed Vacuum Lighter-Than-Air Vehicle

Kerestes, Jared N. 02 June 2021 (has links)
No description available.
44

Matematicko - fyzikální analýza dynamického tlaku pro experimentální diferenciální komoru. / Mathematical-physical analysis of dynamic pressure for the experimental differentially pumped chamber

Lepltová, Kristýna January 2018 (has links)
This thesis is based on the series of scholarly article dedicated to the issue of pumping in the differential scanning chamber of an environmental scanning microscope. The thesis is based on Danilatos’s study where the pumping of the differential pumped chamber is solved by means of the Monte Carlo statistical method. The thesis analyzes gas flow in the experimental chamber using the Pipot tube. The analyses will be used for the design of the experimental chamber which will serve for the experimental evaluation of the flow results in the chamber using the continuum mechanics.
45

Analýza vlivu umístění kónické clony v nadzvukovém proudu v komoře diferenciálního čerpání. / Analysis of the impact of the conic aperture placement in the supersonic flow in the differentially pumped chamber

Rous, Miroslav January 2018 (has links)
The thesis is focused on the medium dynamics simulation in the environmental scanning electron microscope. Specifically, it researches (examines) the conical aperture location effect in the differential pumped chamber and the width of the pumping channel in this chamber. The theoretical part deals with the environmental scanning microscope generally and other tools used in this thesis, e.g. ANSYS Fluen software, fluid turbulence, medium free path of molecules and electrons scattering. In the practical part, the work is focused on data processing from the ANSYS Fluent program and on their evaluation.
46

Výpočtová analýza proudění v bubnové sušičce prádla / Computational analysis of fluid flow in a tumble dryer

Dohnal, Miloslav January 2014 (has links)
The aim of this work is to create a computational model of radial industrial tumble dryers, to calculate and identify the amount of air that flows through the inside of the drum itself. The calculation will be performed via computational fluid dynamics (CFD). Furthermore, compile transient balance model of mentioned dryers. Perform simulation balance model and compare the results of simulations with experimental measurements. By comparing the experimental data and simulation to determine the degrees of freedom of balance model and evaluate their impact on the assembled transient model. For a better understanding of the drying process, there is constructed a system of differential equations describing heat and moisture within the material being dried on a simple model. In the section devoted to the computational analysis of fluid flow is analyzed existing geometry of the drum, which has a major impact on the flow of air inside the drum itself. Following describes how to simplify its complex geometry entering the computational fluid dynamics. Then, there is carried out a simulation of fluid flow inside the tumble dryers using MRF and Sliding Mesh models. Finally, there is an analysis of the data obtained and determined the average amount of air flowing through the drum itself. On the contrary, the aim of the work is not to create another text tool for students engaged in CFD theme.
47

Výpočtové modelování aerodynamického hluku při obtékání tělesa / Computational modelling of aerodynamic noise of flow past a solid body

Sýkora, Daniel January 2016 (has links)
Diploma thesis is focused on computational modelling of aerodynamic noise of flow past a solid body. Computation of flow around a cylinder is performed for different meshes and time steps in initial part of the thesis. Results from every computation are compared. Computation aerodynamic noise due to flow around a cylinder is simulated in other part of diploma thesis. In the second benchmark computation, turbulent models have to be considered, because flow with high Reynolds number is turbulent. Computation is based on two different ways: acoustic analogy and direct method. A few different turbulent models is described and is analyzed influence to modelling aerodynamic noise. The results and knowledge of the benchmarks computation have been used in compu-tational modelling of aerodynamic noise of flow around simplified side view mirror. Surface (2D) and spatial (3D) simulations are performed. Based on computation modelling of aerodynamic noise of flow around simplified side view mirror has been designed new geometry, that aim is reduced aerodynamic noise and improved aerodynamic parameters.
48

Analysis of the Inner Flow in the Wave Energy Converter WaveTube

Kapell, Jennie January 2012 (has links)
Wave energy technology is currently growing and gaining popularity. With around 100 separate technologies researched globally in over 25 countries wave energy are believed to soon be able to compete with other renewable sources such as wind energy. One of the new technologies is WaveTube; a wave energy converter currently under development and in need of technical verification. The basic idea of WaveTube is a partially submerged container with an enclosed fresh water volume. The kinetic energy of the ocean waves are transferred onto the floating container, creating an inner flow in the structure and electricity is generated as the fresh water flows through turbines. Previous small-scale model tests have confirmed the basic idea of WaveTube and an inherent continuation is visualizing and evaluating the inner flow using Computational Fluid Dynamics. A simplified 2D simulation where the WaveTube structure is subject to a pure sinusoidal, rotational motion was believed to be able to give useful information about the inner flow field. However, this Master Thesis project shows that a simulation using ANSYS Fluent of this case is not a successful approach. With inner moving parts a so called dynamic mesh was required, which updates the mesh as the boundaries move. In order for this method to be successful the mesh needs to be of high quality. However, for the complex geometry that WaveTube is no mesh was found to meet the requirements and the calculations using the Volume of Fluid method were not able to proceed.
49

Aerodynamic Analysis of a Blended Wing Body UAV

Harrisson, Oliver January 2022 (has links)
The focus of this thesis is to analyse the flight characteristics of the blended wingbody (BWB) unmanned aerial vehicle (UAV) Green Raven currently being developed by students at the Royal Institute of Technology (KTH) in Stockholm,Sweden. The purpose of evaluating a BWB aircraft is due to its potential increasein fuel efficiency and payload compared to conventional aircrafts which would enable more sustainable flights. The analysis is conducted in ANSYS Fluent 2020R2 where the goals are to extrapolate lift, drag and pitching moment coefficients,aerodynamic efficiency and evaluate stall patterns. The analysis is conducted with free stream velocities from 5 m/s to 40 m/s with5 m/s increments at angles of attack from −4◦ to stall plus 4◦. The result of thisthesis is that an analysis have not been able to be conducted due to a lack ofcomputational power. Thusly, the conclusion to this thesis is that to be able toperform a complete analysis of the Green Raven, a more powerful computer needsto be used.
50

Modeling of Heat Transfer in LDConverter (BOF) Lining

Jahan, Georgina January 2012 (has links)
During the production of steel in the LD converter the refractory lining is exposed to high temperature emulsion of steel, slag and gas. It protects the steel body of the vessel to come in contact with the molten steel.The main purpose of this work was to observe the temperature distribution profile in converter refractory lining which is very important to understand the life of the refractory lining of the LD converter.In this study, a three dimensional (3D) heat transfer model for the refractory lining of converter was developed. The lining of the refractory material was considered as magnesite brick for inner lining, dolomite for intermediate lining and steel shell as outer part. In order to do the numerical modeling, the CFD software Ansys Fluent 13.0 was used. After considering the proper dimensions, meshing, properties of the lining material and boundary conditions, the modeling in Ansys was performed in two stages. In the first stage, the modeling was performed by assuming that the converter is already heated and the inside temperature of the furnace is 1923K and the outside temperature of the steel body is 300K. In the second stage, the temperature change of the molten steel, slag and the gas was considered as function of blowing time and slag height based on theories from different references. Firstly, the three dimensional (3D) heat transfer model was used for the refractory lining of the converter to show transient heat flow through the lining at different times. Secondly, 3D modeling results from fluent 13.0 was used to develop temperature distribution profile through the lining at different height for different time steps and at different positions with time and also along the converter height from the bottom to top. It has been noticed that refractories in the lining in contact with steel and slag must be of good quality for the reduction of wear cost and downtime and therefore the reduction of refractory cost per ton of steel production.

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