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499 Uppsatser om Fluid simulation - Sida 22 av 34

Hur ökad fukthalt påverkar pannor

This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor.

Gestaltningsförslag till ny förskola på Zakrisdal

Due to increasing regulations regarding new diesel vehicles particulate matteremissions the new Scania truck, Scania Euro 6, has been equipped with a particulatefilter. This component effectively stores the particles in the exhaust gas but must becleaned in order to prevent itself from clogging. The filter is cleaned through aprocess named regeneration which is a thermodynamic process in which thetemperature of the filter is raised through fuel supplied to the exhaust gas.The purpose of this thesis is to contribute to the development of improved controlstrategies of the temperature during the regeneration process through thedevelopment of model-based controllers. These controllers are designed in order tohave good performance in stationary as well as automatic regeneration.In order to develop these model-based controllers a model of the system isconstructed. The model is described as a linear thermodynamic grey-box model withflow varying parameters, showing good results in validation.The model provides a simulation environment during the controller design, which isfocused around the development of linear regulators with the exhaust gas mass flowas a scheduling variable whose size determines controllers? mode of operation.

Utveckling av en Multi-Zonsmodell för NOx Bildning i Diesel Motorer

This thesis work is the last part of the Master of Science education inmechanical engineering at KTH, Stockholm.The aim of this project was the development of a Multi-zone modelfor NOxformation in Diesel engines. Because of the stringent emissionlegislations, great effort is made to decrease the fuel consumption and theharmful emissions of internal combustion engines. Computer simulationsplay a decisive role in this context because they substitute the expensiveand time-consuming laboratory tests.The model is based on a multi-zone approach and uses the wellknownExtended Zeldovich Mechanism which gives a relation to calculatethe NO formation rate using the concentration of different gas speciesinvolved in the process.All the most important phenomena involved in the Diesel combustionhave been modelled. A special attention is then paid to the equilibriumconcentration calculation; this is a significant part of the model whichstrongly influences the following steps.A Simulink model has also been developed. This second version isbased on the previous model and it is made especially to allow theconnection with other external softwares, GT-power in this case.

Matematisk generering och realtidsrendering av vegetation i Gizmo3D

To render outdoor scenes with lots of vegetation in real time is a big challenge. This problem has important applications in the areas of visualization and simulation. Some progress has been made the last years, but a previously unsolved difficulty has been to combine high rendering quality with abundant variation in scenes. I present a method to mathematically generate and render vegetation in real time, with implementation in the scene graph Gizmo3D. The most important quality of the method is its ability to render scenes with many unique specimens with very low aliasing.

Uppbyggnad och reglering av en pumpstation till ett injektionssystem

I was assigned to the thesis as part of a project GMA AB (Ground Machinery Applications AB) is running. The project aims to develop a new method for injection of drilled holes in rock walls. Currently, the injections usually involve cement but the basic idea of the project is to replace cement with a supplement called Silica sol.Silica sol is known as a gelling liquid. The gel time is controlled by a mixing of saline. Depending on the amount saline that gets mixed in, the gel time varies.

Utbildningssimulator av funktioner i spa?rfordon : Ha?rdvarusimulator med felso?kning pa? do?rrsystem

This report is a description of a developed educational simulator over rail vehicles and its components. The simulator is a hardware-based prototype over a door system on rail vehi- cles. System specialists and technicians will use the prototype. The Simulator should give the user a technical demonstration on how components work in a door system. The proto- type consists of motor, switch, relay and sensor.

Inledande studie inför utveckling av ett virtuelltmikroskop för utbildning inom livsvetenskaperna

Forskning med hjälp av mikroskopi har med tiden ställt merspecialicerade krav på utrustning som används. Utrustningenhar blivit mer bättre men samtidigt också dyrare. Enhög kostnad innebär att avancerad mikroskopi inte kan användassom ett utbildningsverktyg inom grundutbildning.Dagens studenter tvingas på så sätt förberedas för framtidensforskning genom att använda gårdagens utrustning.I detta arbete visar vi hur virtuell mikroskopi kan användasför utbildning och forskning. Virtuell mikroskopi kananvändas som komplement, eller möjligtvis ersättning, förbefintlig undervisning. Vi har demonstrerat detta genomatt utveckla en pilotapplikation som simulerar de två metodernaFLIP och FRAP.

Prognosanvändning i företag

Inledning: Många företag genomför idag någon form av prognos som underlag för deras beslut.Det kan handla om prognoser för hur mycket marknaden kommer att efterfråga, hur storakostnader företaget förväntas ha eller hur mycket personal som kommer krävas.Problemformulering: Hur använder företag prognoser i sin verksamhet?Syfte: Syftet med den här uppsatsen är att beskriva och förklara hur prognoser används i företag.Metod: Den här studien har byggt på en kvalitativ forskningsstrategi. Arbetets forskningsansatshar varierat mellan en induktiv metod och en deduktiv metod. Uppsatsens empiriska material harinförskaffats genom semistrukturerade intervjuer på två utvalda företag; Galenica AB och SAABtraining and simulation.Resultat och slutsats: Undersökningen visar att företag använder prognoser som grund för attfatta beslut. Prognoser används främst som grund för budgetarbetet, men företag upprättar ävenprognoser över andra faktorer som påverkar företagets framtid.

Konstruktion Signalgenerator

SAAB Aerotech division FGR in Arboga builds and develops equipment and components used in both military and civilian applications. To build a test system for a specific project that SAAB is responsible for requires a simple signal generator that can provide a pulse modulated signal. The need to buy a new advanced signal generator for example from Agilent is not as profitable as the instrument is expensive and contains features that SAAB does not require in their applications and test systems. That was the reason why SAAB offers two students a thesis where the goal is to construct a signal generator in accordance with what SAAB requests.This thesis contains several different phases. The first step was a meeting with our supervisor Mats Bergman and by reading the data sheets for components to be used in the project, with these information and specifications that we have received from SAAB we started to construct the signal generator.What we did during the construction work was to simulate and draw a schematic to be able to design the circuit board.

Premiepensionens Marknadsrisk : En Monte Carlo-simulering av den allmänna pensionen

A reforming trend is captured showing that countries are shifting from defined benefit pension systems towards defined contribution systems. The reforms have been justified through predictions that the defined benefit systems will not manage to provide good enough pensions to members in the future. The newer defined contribution pension plans often include individual financial accounts where individuals have the possibility to choose how a part of their pension savings should be invested. Sweden was early to introduce such a system, which at the moment provides more than 800 funds to choose from. The aim of this thesis is to capture the market risk associated with these individual investments and does so by using Monte Carlo simulations for six selected pension funds.

Inledande studie inför utveckling av ett virtuellt mikroskop för utbildning inom livsvetenskaperna

Forskning med hjälp av mikroskopi har med tiden ställt merspecialicerade krav på utrustning som används. Utrustningenhar blivit mer bättre men samtidigt också dyrare. Enhög kostnad innebär att avancerad mikroskopi inte kan användassom ett utbildningsverktyg inom grundutbildning.Dagens studenter tvingas på så sätt förberedas för framtidensforskning genom att använda gårdagens utrustning.I detta arbete visar vi hur virtuell mikroskopi kan användasför utbildning och forskning. Virtuell mikroskopi kananvändas som komplement, eller möjligtvis ersättning, förbefintlig undervisning. Vi har demonstrerat detta genomatt utveckla en pilotapplikation som simulerar de två metodernaFLIP och FRAP.

Energieffektivisering och solenergi i en universitetsbyggnad : Undervisningshuset och Biblioteket i Uppsala

Akademiska hus is a real estate company that specializes in providing Swedish universities with housing facilities for educational and research purposes. The company strives to reduce its use of energy by 40% between the years 2000 and 2025. The aim of this thesis is to determine which measures can be taken to reduce the need of purchased energy in a building that is used by theSwedishUniversityof Agricultural Sciences inUppsala.In order to determine the results of various changes to the building envelope and ventilation system, the building was modelled in the computer simulation program VIP-Energy. Other proposed changes to make the use of energy more efficient concerned water use and lighting. The need of purchased energy can also be reduced by producing electricity or heat on site, using solar energy.Results show that economically viable measures include upgrading windows and faucets, adjusting control systems for ventilation and lighting, and installing roof mounted solar panels for power production.

Banken som relationsskapare

Bakgrund: I och med att Basel II har instiftats i Sverige så måste finansiella institutioner beräkna sin marknadsrisk på sina portföljer. Detta kan göras genom olika VaR metoder. Dessa ger dock olika uppskattningar på marknadsrisken. De finansiella instituten får använda sig av den metod som de anser reflektera marknadsrisken bäst. Det finns dock ingen metod som utsetts till standard.Syfte: Syftet med detta arbete är att jämföra olika VaR-metoders skattning av marknadsrisken utifrån verkligt utfall, för att urskilja vilken metod som är funktionsdugligast.Avgränsningar: Denna undersökning inkluderar fyra olika VaR metoder.

Lathund för 2000-talet : Utvecklingen av en användarcentrerad sökfunktion och en undersökning i utbildningens roll vid införandet av nya IT-system

Forskning med hjälp av mikroskopi har med tiden ställt merspecialicerade krav på utrustning som används. Utrustningenhar blivit mer bättre men samtidigt också dyrare. Enhög kostnad innebär att avancerad mikroskopi inte kan användassom ett utbildningsverktyg inom grundutbildning.Dagens studenter tvingas på så sätt förberedas för framtidensforskning genom att använda gårdagens utrustning.I detta arbete visar vi hur virtuell mikroskopi kan användasför utbildning och forskning. Virtuell mikroskopi kananvändas som komplement, eller möjligtvis ersättning, förbefintlig undervisning. Vi har demonstrerat detta genomatt utveckla en pilotapplikation som simulerar de två metodernaFLIP och FRAP.

Implementering av höghastighetsgränssnitt i 0,15 µm halvledarprocess

This study investigated the possibility of implementing three standards, Transistion Minimized Differential Signaling (TMDS) and two versions of Stub Series Terminated Logic (SSTL), for inter-chip communication in a specific manufacturing process. The two SSTL standards were implemented in one transceiver system while TMDS was implemented in a separate system. The evaluation was done with Spice simulations on schematic level with some parasitic capacitance and resistance. The idea was to investigate the possibility of implementing these standards and get an idea of eventual shortcomings. In order to create models as a basis for evaluation, simulation environments with models for circuit board and packages were created and transmitters and receivers were designed.

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