Sök:

Sökresultat:

416 Uppsatser om Monte Carlo simulation - Sida 4 av 28

Utveckling av en dynamisk Simuleringsmodell av en skotare

The predominant forestry harvesting method is based on the harvester-forwarder method, theharvester folds, branches and cuts trees, and sorts the logs into piles, while a forwarder transportsthe logs to a landing area.This master thesis work is about realization of a dynamic forwarder simulation model, and itspurpose is to provide an integrated forwarder simulation model in MATLAB/SimMechanicswhere the forwarder is based on a concept using pendulum arms to connect wheels and chassis.Active suspension control is developed and implemented into the simulation model, and finallycompared in simulation with passive suspension.In a first step, an integrated forwarder simulation model is developed, containing a simplifiedforwarder model, a tire-to-ground interaction model and a test track model. The simplifiedforwarder model is based a rigid multi-body system with a spring-damper suspension of thependulum arms. The tire-to-ground interaction model calculates the reaction forces, friction fromthe ground and applies the propulsion force. The test track model is a simplified version of thereal test track in Skogforsk. The propulsion wheel torque control is used to regulate theforwarder speed.

1-D Modellering av Piezoelektrisk Injektor

A piezoelectric injector was modeled, in this Master Thesis Project which was carried out at Scania CV AB in Södertälje, in GT-Fuel. GT-Fuel is simulation program from Gamma Technology.The simulation model for the piezo injector was divided into a hydro-mechanical system and an electrical system (Piezoelectric element). First the hydro-mechanic model was duplicated from Advance Continuous Simulation Language model (ACSL). The simulation results were then compared to the ACSL, to verify that the hydro-mechanical system was modeled correctly. The simulation results for the electrical model were also compared with a Simulink model.

Förutsättningarna för ett parallellt generation IV system vid svensk nybyggnation av kärnkraft.

A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.

MCNP-modell för beräkning av neutrondos och DPA på reaktortanken vid Ringhals 2

In this report an MCNP (Monte Carlo N-Particle) model is described for the reactor vessel at Ringhals 2. The model is validated against the specific activity in neutron dosimeters, extracted in 1977, 1984 and 1994. The validation showed that the calculations of the model are within the requirements of a maximum of 20 percent uncertainty for every neutron dosimeter except one, extracted after the first cycle. The uncertainty of this cycle was mostly due to the operation data rather than to the MCNP model.The model has been used to investigate various questions concerning radiation damage. The reliability of the traditional measure of radiation damage, fast neutron flux (En > 1MeV) has been evaluated.  This has been done by taking the ratio for this and another measure of radiation damage, DPA (Displacement Per Atom), for various positions and layers.

Simulation driven design : An iterative approach for mechanical engineers with focus on static analysis

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.

Simulering av simulinkmodeller med Extended Kalman Filter

Simulations of simulink models using Kalman filters are often very time-consuming. This problem depends mainly on the fact that the Kalman correction has to be performed at each sample instance through the whole simulation. The goal for this thesis work is to reduce that time-consumption for the filtering part (the integration partis treated in a complementary report) of a simulation. Furthermore a Matlab routine to perform parameter tuning and finally a graphical user interface is developed.The filtering part of the simulation in this thesis is based on an Extended Kalman Filter (EKF). The time optimization of this filter considers searching for the possibility to replace the today?s existing Matlab functions that is used to perform the filtering calculations.

Real Optionsanalys - En fallstudie på SCA Packaging

Syftet med uppsatsen är att identifiera och värdera eventuell flexibilitet i en traditionell investering med hjälp av Real Options Analys. Traditionella statiska investeringsverktyg tenderar att undervärdera projekt. Ett verktyg har senare utvecklats för att kunna värdera osäkerhet och flexibilitet, ofta inneboende i projekt. Uppsatsen är en fallstudie på SCA Packaging och utgår från en deduktiv ansats där data har inhämtats via personliga intervjuer. Historisk analys av de variabler som har störst påverkan på projektet, genomförs med Monte Carlo simulering.

En fordonsförares upplevelse av accelerationer som grund för en effektiv simuleringsmodell

Saab Aerosystems has a long tradition and a lot of competence in the field of flight simulation. Their ambition to broaden the market horizon has led to a discussion about also selling vehicle simulation solutions, both for military and civilian use.The aim of this thesis is to investigate the driver?s experiences of the accelerations he or she is exposed to whilst driving in rough terrain. The results may be used as a basis for future decisions and can act as a platform for the construction of an effective simulation model.To investigate the driver?s exposure of acceleration, some kind of dynamic simulation is needed.

Simulation driven design : An iterative approach for mechanical engineerswith focus on modal analysis

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.

Hur enkel- & dubbelportsturbin i kombination med två olika avgassamlare påverkar gasväxlingsprestanda på en Scania V8

The exhaust arrangement on a Scania V8 consists of one manifold at each bank connected to a twin entry turbine (8-2-2). A study in GT-Power has shown improved performance and reduced cylinder to cylinder variations using two manifolds at each bank in combination with a single entry turbine (8-4-1). This thesis work analyses the difference in performance shown in simulation and verify it by engine test.The initial work was focused on simulation in GT-Power. Investigating how exhaust manifold volume and pulses effects the turbine efficiency and the mean effective pressure during the gas exchange. To verify GT-Power simulations four engine tests with different exhaust arrangement have been made.The results from GT-Power simulation indicate that a larger exhaust volume improve the turbine efficiency.

Modellering av Panna 5 Mälarenergi AB : utveckling av en beräkningsmodell med simuleringsverktyget IPSEpro

Heat and power stations are often in need of optimizations. A simulation model is a tool for findingways to optimize the plant. The scope of this diploma work is to develop a simulation model ofBoiler 5 at Mälarenergi AB. Boiler 5 is a circulated fluidized bed boiler that was taken into service inyear 2001. Among the included parts in the boiler are cyclone, convection part andINTREX-chambers.

Jämförelse av olika reglersystem för undervisningsändamål

Examensarbetet syftar till att jämföra nya alternativ till olika system för användning i laborationer i reglerteknikkurser för olika studentkategorier. Det skall utredas vilket av ett antal alternativ till mjukvaruplattformar som är bäst lämpat att användas vid reglerteknikundervisningen i ITN:s reglerlaboratorium vid Linköpings universitet. Tidigare laborationer i berörda kurser skall även modifieras så att dessa kan genomföras i de nya systemen.Examensarbetet resulterade i en rad modifierade laborationer och system att tillämpa i dessa. De nya systemen medför att all reglering sköts direkt från en dator istället för tidigare variant med externa apparater som programmeras. På så sätt kan större fokus läggas på regleringen i sig och inte de system som tillämpas för att utföra den..

Vision eller Verklighet ? Vad säger kontoret om företaget som sitter där?

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.

FPGA baserad PWM-styrning av BLDC-motorer

This thesis work contains a litterature study about electrical motors in general and how PWM-patterns for brushless DC-motors can be made. A suitable method has been implemented as a simulation model in VHDL. A simulation model of a brushless DC-motor which describes the phasecurrents, torque and angular velocity has also been made. The motor model made simulations easier for the complete PWM-system. The design was synthesised and tested with a prototypeboard including a SPARTAN II FPGA.

Simulation driven design : An iterative approach for mechanical engineerswith focus on mesh, quality and convergence

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.

<- Föregående sida 4 Nästa sida ->