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370 Uppsatser om Numerical simulations - Sida 18 av 25

Energikartläggning av polishuset i Gävle : Åtgärdsförslag för ett minskat energibehov i fastigheten Gävle Söder 17:10

The objective of this work was to introduce measures to reduce energy and water demand at Gävle Söder 17:10. To succeed, this energy audit has been made. The work is based on collected statistics from the property owner Norrporten, measurements, literature review and through consultation with experts in the field. Two models, one for each building, have been created in the simulation program BV2 to estimate the potential of energy measures based on the collected information. The models in BV2 have been verified against the statistics of the energy consumption.With the help of calculations and simulations, seven cost-effective measures have been identified.

Optimering av slutfasstyrning

Modern missiles must meet higher and higher demands. They should be autonomous, have long range and still have a big effect on the target. To maximize effect on target some missiles not only minimize miss distance, but also try to hit with a certain angle; often perpendicular to the surface of the target. In this thesis a method to guide the missile in the terminal phase of its mission where both point of impact as angle of impact are specified. The method consist of two parts.

Microstrip Solutions for Innovative Microwave Feed Systems

This report is introduced with a presentation of fundamental electromagnetic theories, which have helped a lot in the achievement of methods for calculation and design of microstrip transmission lines and circulators. The used software for the work is also based on these theories. General considerations when designing microstrip solutions, such as different types of transmission lines and circulators, are then presented. Especially the design steps for microstrip lines, which have been used in this project, are described. Discontinuities, like bends of microstrip lines, are treated and simulated.

Analys och dimensionering av robusta kilspårsförband

This master thesis comprises analysis and dimensioning of a keyed joint between a generator axis and a hub with aid from the FEM-software ANSYS Workbench 13.0.The generator axis is a part of a hydroelectric power station that generates electricity with a reactions turbine, a Kaplan turbine. The existing keyway consists of one parallel key with the width 90 mm and height 45 mm. Due to a planned increase of the power of the generated power with 32 % a design study was needed to see if the keyed joint would be suitable for the extra force. Because of the fact that the axis diameter is bigger than the standards covers/recommends a the keyway had to be re-dimensioned. In an earlier assignment from Skellefteå Kraft AB to Sweco Energuide the keyway was planned to be properly dimensioned, but no final solution was approved.During this master thesis a number of different numerical tests were made.

Undersökning av energiförbrukning och konceptutveckling av mer energisnåla frukostmaskiner

This master thesis comprises analysis and dimensioning of a keyed joint between a generator axis and a hub with aid from the FEM-software ANSYS Workbench 13.0.The generator axis is a part of a hydroelectric power station that generates electricity with a reactions turbine, a Kaplan turbine. The existing keyway consists of one parallel key with the width 90 mm and height 45 mm. Due to a planned increase of the power of the generated power with 32 % a design study was needed to see if the keyed joint would be suitable for the extra force. Because of the fact that the axis diameter is bigger than the standards covers/recommends a the keyway had to be re-dimensioned. In an earlier assignment from Skellefteå Kraft AB to Sweco Energuide the keyway was planned to be properly dimensioned, but no final solution was approved.During this master thesis a number of different numerical tests were made.

Dämplindningens inverkan på spänningens kurvform i en vattenkraftsgenerator

Harmonics are a well-known problem that has to be dealt with in the design of thegenerator. Internationally accepted standards limits the amount of harmonics allowedin the no-load voltage. These limits can be difficult to fulfill with integral slot winding,where the number of slots per pole and phase is an integer. The presence of thedamper winding often makes the problem with harmonics even worse and harmonicswith frequencies of order 6q±1 arise with significant amplitude. How the damperwinding is designed affect the content of harmonics in the no-load voltage and the aimwith these ? has been to investigate in which extent design of the damper windingaffects the contents of harmonics.Simulations with the 2-D finite element method have showed that if the damper barsis centered in the pole shoe, the amplitude of the harmonics of order 6q±1dependsboth on the ratio between the stator slot pitch and damper bars slot pitch and if thedamper bars are connected between the poles or not.If the damper bars is displaced with ¼ stator slot pitch alternately, the amplitude ofthe harmonics of order 6q±1 is reduced and the influence of the ratio between thestator slot pitch and the damper bars slot pitch will vanish.

En simuleringsmiljö för distribuerad navigering

This master thesis studies distributed navigation which isa function implemented in a future network based combat information system to improve the accuracy in navigation for combat vehicles in a mechanized battalion, above all in the event of loss of GPS. In the event of loss of the GPS the vehicles obtain dead reckoning performance through the backup system that consists of an odometer and a magnetic compass. Dead reckoning means a drift in the position that makes the accuracy in the navigation worse. The distributed navigation function uses position and navigation data with measurements between the vehicles to estimate the errors and uncertainties in positions, which are used to improve the accuracy in position for the vehicles. To investigate and demonstrate distributed navigation, a simulation environment has been produced in Matlab.

Kartläggning av energianvändning under byggfasen vid nyproduktion av flerbostadshus

The energy consumption in the sectors of residential and public buildings is 40 % of the total energy consumption in Sweden. The main part, 85 %, of the energy use in these sectors is for operation of the buildings. The rest is used in the building process. When energy-efficiency measures are taken the energy use during the operation time decreases and the fraction of energy consumption during the building time increases. This project is carried out in cooperation with JM AB and concerns the energy use during the building time of production of blocks of flats at the building site.The main part of the electricity that is used during the production of apartment buildings goes into the heating of portacabins and illumination of the building during the construction phase.

Automatiska GUI-test : En teoretisk och praktisk studie för hållbarare test

To automate software testing is an investment, and that makes it important to have good knowledge about automation before an implementation is made. In this master thesis a study about automated testing is carried out. The study also includes a closer look at the testing tool TestComplete. TestComplete is one out of many tools on the market that is developed for automated GUI testing and the goal is to get a picture of how well the tool can adjust to CC Systems own applications. Studies show that it is hard to write lasting test scripts.

Energioptimering : Resteffektkylning av mellanlager för använt kärnbränsle (CLAB) Oskarshamn

This thesis is done in cooperation with SWECO Energuide in Växjö. They have been assigned by SKB in Oskarshamn to renew their electrical power supply and the ancillary processing systems in their Central provisional storage of spent nuclear fuel, CLAB. Today in the CLAB facility, the spent fuel is cooled down with water pumps, driven by asynchronous induction motors, where the water is regulated by mechanical valves to the desired flow. After the upgrade, the engines will be powered by AC drives that can control the pumps by changing the rotational speed and thus change the water's cooling effect on the nuclear fuel. In this study, I investigated the interference AC drives causes the feeding network and how to go about averting them.

Simulering av hydrauliska dämpare i borrslagverk

This master thesis consists of the creation of shock absorber models for percussive rock drills. A model of the rock was also developed. These models were connected to existing models of the rock drill to create a complete simulation of the rock drilling process.When the models had been created the rock model was evaluated by comparison with measured values from lab tests. The verified rock model was then used to evaluate the shock absorber models.Four new shock absorber concepts have been developed. Three of these have been modelled, while the fourth have only been sketched and described.The evaluation of the models showed the following:? Simulations of the single shock absorber don?t correlate to reality very well.

Fuktomlagringar i välisolerade ytterväggar : En undersökning för att fastställa en rimlig inbyggnadsfuktkvoti träreglar med fuktsimuleringsprogrammet Wufi 2D

To save energy it?s popular to build houses with low energy loss. In these houses the walls are keeping a lower temperature in the external side which leads to a higher relative humidity. In addition more material, such as wood studs, are used which means that there is more moisture to dry. More moisture in combination with higher relative humidity may pose a higher risk of microbial growth.

Föräldrars upplevelser av att förlora ett barn i cancer

It is not uncommon for math difficulties and reading difficulties to occur simultaneously. Despite this, math and reading difficulties are thought to have different cognitive profiles where math difficulties are linked to number sense; an innate ability to understand, approximate and manipulate both quantities and numerical information, whereas reading difficulties are linked to phonological ability; an innate ability to understand, create representations of and manipulate phonological information. A possible link between the difficulties is that phonological abilities also could affect mathematical ability. Support for this comes from studies where comorbid math and reading difficulties are associated with more severe difficulties in arithmetic ability compared to those with isolated math difficulties. The purpose of this study is to examine whether isolated math difficulties, isolated reading difficulties and comorbid math and reading difficulties can be linked to deficits in number sense, phonological ability or both of these, and whether comorbid math and reading difficulties differ in performance in mathematical tasks compared to isolated math difficulties for children in second grade.

Behavior Cards - ett programmeringsverktyg för barn

This thesis presents the work of developing and testing a programming tool specially designed for children. The purpose of this tool is to make children capable of creating visual simulations and games that consist of actors interacting in a virtual world. The name of the programming tool is Behavior Cards, which comes from the fact that actors are programmed by giving them cards representing different kinds of behaviors. Behaviors are to some extent pre-programmed and can include general events specifying how the actors should act in different situations, in contrast to specifying every possible situation that can occur. The idea is that Behavior Cards should be easier to use than a more traditional text based programming tool, but it should also be expressive within the domain of visual games.

Integration av simuleringsmodeller för bränslesystemet i JAS 39 Gripen

In this final thesis two simulation models have been integrated. The simulation models are models of JAS 39 Gripen?s fuel system, software and hardware. The time consuming and costly work to develop software has made the department of fuel system to build two models in Xmath/Systembuild. The software model also simplifies the comprehension of how the software in the control computer of the fuel system works.

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