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370 Uppsatser om Simulation - Sida 4 av 25

Analys av turbulensmodeller för CFD

This thesis has been a part of Forsmarks Kraftgrupp AB's evaluation of a turbulencemodel used in Simulation of turbulent flow called PRNS (Partially Resolved NumericalSimulation). This model has promising properties and may be of use in savingcomputational resources. The purpose of this thesis was to analyze this model andcompare it with industrially applied models such as k-omega SST and LES (Large EddySimulations).PRNS works as a hybrid of the k-omega SST and DNS (Direct Numerical Simulation)where a constant, RCP (Resolution Control Parameter) with a value between 0 and 1are selected. This constant is then used in the calculations and determines thebehavior of the Simulation. When RCP is set to zero the equation are the same as fora DNS Simulation and when RCP is set to one the equations for k-omega SST issolved.

Aktivitetsbaserat kontor eller öppet kontorslandskap? ? En multivariat studie av attityder till kontorstyperna

This thesis of 15 hp has been implemented at Halmstad University, in collaboration with Saab Dynamics in Linköping. Saab Dynamics is a company operating in the defence industry where competition is tough. This necessitates new ways to increase efficiency in the company, which is the basis for this thesis. Saab Dynamics wants to introduce Simulation driven design. Since Saab Dynamics engineers have little experience of Simulation, required a user methodology with clear guidelines.

Modellering och reglering av drivenheter i gaffeltruck

To enable the enhancement of the driver's environment in a forklift, an alternative form of steering has been evaluated. An earlier concept with a combined driving and steering wheel has been exchanged to a concept with two driving wheels. A link wheel has replaced the combined driving and steering wheel. The steering is done through differentiation of the velocities of the two driving wheels. The scope of this master thesis is to create a Simulation model, create a control program and to evaluate the concept of two driving wheels.

Höghastighetståg - Är det framtiden?

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

Rayleigh-Bénard konvektion.

AbstractConsider a ?uid being heated from below. The heating leads to an upward convectiveforce that is counteracted by the viscous forces of the ?uid. If the convectiveforce is large enough in comparison to the viscous forces the ?uid will be put in anunstable state.

Tekniken bakom den digitala filmtekniken : Vilka tekniska faktorer ligger till grund för den digitala revolutionen inom den professionella kameratekniken?

This thesis of 15 hp has been implemented at Halmstad University, incollaboration with Saab Dynamics in Linköping. Saab Dynamics is a companyoperating in the defence industry where competition is tough. This necessitatesnew ways to increase efficiency in the company, which is the basis for this thesis.Saab Dynamics wants to introduce Simulation driven design. Since SaabDynamics engineers have little experience of Simulation, required a usermethodology with clear guidelines. Due to lack of time, they chose to assign thetask to students, which resulted in this thesis.The aim of the thesis is to develop a methodology in mechanical design, wherethe designer uses the FE analysis early in the design process to develop thestructures' mechanical properties.

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.

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.

Parametriserad modell av motorprototyp med Solidworks

The purpose of this thesis has been to build a parameterized model of a prototype motor in the program Solidworks, to use in future optimization of aspects of effectiveness and weight. The result were two models. The first model were one minor part of the whole design in 2D, to be able to optimize and study the minor part with a faster loss Simulation. The second model was the whole design in 3D. The whole model were done with the three programs Solidworks, Comsol and Matlab.

Effektiv partiformning : analys och tillämpning på Uppåkra Mekaniska AB

This paper is the result of a case study conducted at Uppåkra Mekaniska AB during the spring of 2006. The task that was presented by Uppåkra was to develop a basis for a decision for the planning activities at the company, so that in the future they can create lot-sizes which are based upon a total cost perspective. Total cost in regards to lot-sizing is defined as the sum of the administrative reordering costs and warehousing cost per stock keeping unit.To collect data a series of interviews and observations were conducted. This data was then used during the lot-sizing Simulation and analysis. The 15 units that the Simulation was conducted on were grouped into three item classes depending how many different machine setups they required during the production process.

Optimering av OTEC-system

Ocean Thermal Energy Conversion, OTEC, is a sustainable energy conversion technology that is not yet commercialized. OTEC is a technology that utilizes the temperature difference in oceans between the warm surface water and the cold water at 1 000 m depth to run a Rankine Cycle. This technology can produce electricity and provide synergies like fresh water, air conditioning and aquaculture. A Simulation program for three alternative OTEC systems has been created in order to decide which OTEC system is most profitable; closed, open or hybrid system. In this Simulation a production cost analysis is performed in order to investigate and decide which one of the three systems that has the lowest production cost. The production cost analysis also analyzes if the profitability is affected by the size of the facility. After these analyzes, the most profitable of the three different OTEC-systems is expanded by an installation of solar collectors in order to see if the thermal efficiency is improved. The result shows that the most profitable system varies with the size of the facility.

????Att lösa reglertekniska problem med Modelica

Modelica is a multi-domain and equation-based modeling language. Modelica is based on object-oriented principles and non-causal modeling. The language is constructed to facilitate reuse and decompose models. The models and the modellibrary can modified to design a new nonlinear components.Object-oriented modeling is an excellent way to analyze and study large complex heterogeneous physical systems. The object-oriented modeling approach build on reusing and decomposition of models and non-causal modeling.Modeling physical systems often leads to a DAE system with index 2 or 3.

Cykeltidsoptimering av sjuaxligt robotsystem

This master thesis studies how much the cycle time, i.e. the time it takes for an industrial robot to perform a given task, can be reduced if an extra degree of freedom (DOF) is added to the robot system. The extra DOF consists of a linear track, which is supposed to be used in an optimal way. The problem has been studied using Simulations in the robot Simulation tool RobotStudio. To be able to run an optimization in Matlab, with the RobotStudio Simulation cycle time as the object function, communication between Matlab and RobotStudio has been set up with an interface written in Visual Basic.

Simuleringsmodell över Ålö AB

During year 2004 Ålö AB made significant change in their production process. The production of front loaders is nowadays highly automated with short operation times. To be able to control their process in a better way Ålö recently decided that they needed a tool for Simulation of their production and to shift patterns. This final thesis started with a pilot study in Ålö?s factory in Brännland.

Robotiserad produktionsanpassad magnetmontering för vågkraftverk

This thesis work includes studies and Simulation how magnetization of the translator in a linear generator for wave power can be automated. The translator is the moving component in the generator that is "dressed" with permanent magnets. The translator is magnetized with rectangle-shaped permanent magnets that are today's strongest permanent magnet type of neodymium-iron-boron (NdFeB).Eight equivalent metal sheets are mounted around the translator. The plates have milled tracks where 106 permanent magnets per sheet are mounted. Today the assembling of the magnets is done by hand, which is a very tedious and time-consuming work.  This project presents investigations about the automation of the translator magnetization theoretically and Simulation results are preformed in ABB's robot Simulation software RobotStudio. Even robot-held tool was designed that enables the robot to be able to magnetize the translator in a simple manner.  The investment cost is roughly 1.5 million SEK. With an economic life-time of five years, the investment costs are estimated to 24000 SEK / month.  According to the calculations, this project is very motivated to implement, as it provides savings up to 17 000 SEK per translator which is 10.2 million SEK assuming that the robot cell is operating at full speed the whole year.According to this thesis work the result is a 4x9 meter cell with two industrial robots of the type ABB IRB6650S.The cycle time to magnetize one translator was calculated to about 10 hours.This prototype of project can possibly be implemented in a full-scale production line and performed according to the calculations and Simulations presented in the report. Further work is suggested to improve the tool.Lyssna .

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