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368 Uppsatser om Mean value engine modelling - Sida 5 av 25

Transportsfordon för rullstolsburna

A vehicle that carries a person sitting in a wheelchair has been rebuilt. The original vehicle was provided with a petrol engine, hydrostatic drive and a mechanical steering rod, making it noisy and hard to maneuver. The purpose with this project was to convert the vehicle to make it more environmental and easier to drive.A new design has been proposed where an electrical drive has replaced the noisy combustion engine and an electrical motor with joystick control has replaced the manual steering.The project was divided into two parts. One mechanical part where the construction of the drive and steering were to be decided. The other part involved programming the microprocessor and implementation of all the necessary electrical for the control system of the vehicle.

CFD simulering av en fyrtakts Otto motorcykel motor

This thesis deals with the numerical 3D simulation of a four stroke, spark-ignited, internalcombustion engine, which is mounted on a high performance motorcycle. The work, carried outin collaboration with Politecnico di Milano and MV Agusta, focuses on the simulation of theintake, compression and expansion stroke, including combustion simulation, using an opensource CFD code.Simulation of internal combustion engines offers a great challenge in the field of CFD research.Moving boundaries of the solution domain, caused by the motion of the piston and valves, leadsto deformation of the computational grid, with decreasing quality of the solution as result. Basedon this, a previously developed mesh motion strategy was employed where a number of meshesare used to cover the whole simulation cycle. Within each mesh interval the internal cell pointsof the mesh are moved to account for the boundary motion of the piston and valves. This strategywas previously applied to simplified geometries as well as real engine geometries.

VVA-strategier för avgastemperaturhöjning på en HD-Dieselmotor

Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder research engine equipped with a hydraulic variable valve actuation system.

Att göra eller inte göra : Hur kontroll och nyfikenhet påverkar regelverket på Facebook

This paper is a literature study on search engine optimization (SEO) considering the leader of the search engine market: Google. There´s an introductory background description of Google and its methods of  crawling the Internet and indexing the web pages, along with a brief review of the famous PageRank algorithm. The purpose of this paper is to describe the major important methods for improved rankings on Google´s result lists. These methods could be categorized as on-page methods tied to the website to be optimized or off-page methods that are external to the website such as link development. Furthermore the most common unethical methods are described, known as ?black hat?, which is the secondary purpose of the text.

Akademiska söktjänster: En jämförande studie av Google Scholar, MEDLINE och Web of Science

The purpose of this paper is to compare the three search engines Web of Science, Google Scholar and MEDLINE in regards of recovery efficiency and the overlap of relevant documents when it comes to information searching for academic purposes. Furthermore, it raises the question whether freely available search engines and licensed search engines are interchangeable with each other. The empirical data in this study were collected through searches conducted in the three search engines Web of Science, Google Scholar and MEDLINE. Twenty search queries were used and the first twenty retrieved documents for each query were examined for relevance using previously designed criteria. The documents were scored by a binary relevancy scale and thereafter a precision value for each search engine was calculated.

Beslutsmodell för inköp och lagerhållning av motorer i ett produktionssystem : En fallstudie på Sandvik

AbstractIt is important to choose which spare parts to keep in stock. With the right spareparts in stock the costs for inventory and production loss will decrease. Cavalieri et al. (2008) highlights that the balance between inventory cost and production loss is underestimated.  It affects the company and must be considered before decision on purchase.The problem with spare engines is that they are all more or less critical for the production. That can be a reason for why no previous research targeting engines and classification of with engine should be kept in stock has been found.

Avbördningskapacitet för Traryd kraftverk: en modellstudie vid dimensionerande flöde

Sydkraft Vattenkraft AB owns and operates the Traryd hydropower plant, located in the river Lagan in the southern part of Sweden. The gravity dam is classed according to RIDAS guidelines (Hydropower Industry Dam Safety Guidelines) as a class 1B dam. This means that the dam must discharge a class 1-flow which has a return period of 10 000 years. The inflow into the dam has been calculated in an earlier report to 495 m3/s, with a waterline at an elevation of 126, 3 meters above sea level. The gravity dam has a discharge system with two rectangular weirs, which results in a smaller discharge than the necessary 495 m3/s.

3D modelling of a Laser Welding Cell for movie presentation : making of the movie

This report describes a Bachelor thesis work in which a robotised laser welding cell has been modelled and simulated for the purpose of making a presentation movie. The report shows that the work has been concentrated on making the movie from the modelling phase through the recording of the movie and ending up with the editing of the final presentation movie. A pre-study was made prior the Bachelor thesis work. In the pre-study a literature study was conducted about measurement and calibration of a welding cell. Measurement of almost all equipment in the entire cell was also conducted in the pre-study.

VÄRDEFLÖDESANALYS AV PW1000G 30k TEC

The thesis work has been carried out at Volvo Aero Corporation (VAC) in Trollhättan. VAC has entered a partnership as developing and producing partner with engine manufacturer Pratt & Whitney and is currently at the starting phase of producing the turbine rear frame (TEC) to the engine PW1000.The purpose of this study was to create a report on process level that describes the conditions and the potential with PW1000 TEC to reach the product cost calculation taking into account lead times and describe alternative method solutions.The report describes a comparison between the present flow (2012), a flow based on product cost calculation (2016) and a potential flow (2016). The work has mainly been based on acquiring the knowledge and information available to inspect the present flow; this has been done by workshop observations, meetings and gathering of the information that is available on the work site for the PW1000 TEC.The information obtained has been merged into an Excel document, called Roadmap. It serves as a roadmap with current situation as the start and the potential flow for 2016 as the goal. With the roadmap as a tool, assumptions have been taken considering the flow and how it will change, where processes have been eliminated, reduced or marked as a problem..

Google Bilders användbarhet : Gränssnitt, sökfunktioner och återvinning

This essay explores to what extent the Swedish language version of Google Images meets the usability requirements of average everyday users. Previously published studies on user behaviour and users? interface and search option preferences define the usability requirements, which are matched against Google Images? actual interface and search options. The retrieval method of Google Images is also briefly discussed, and users? opinions about Google Images too, as they come across in the previously published user studies.The findings are that Google Images lack some of the things that users ask for, but it still seems to be the most used image search engine among average internet users and more appreciated than other search engines.

Dynamisk modellering av kärnreaktor

The purpose of this thesis has been to develop a tool for modelling and simulating the nuclear plant Ringhals 3. The model should be used to improve the knowledge on the dynamics of the plant. Ringhals 3 is being upgraded to produce more power and a tool for analyzing the new operating conditions is needed.The work in this thesis has consisted of improving and developing an existing model of Ringhals 3 made with the modelling tool Dymola. The model has been validated by comparing the results of a simulated house load transient with data from the actual plant. Validation shows good agreement with data from the real plant.

Momentfördelning i pelardäck av armerad betong

The purpose of this thesis has been to develop a tool for modelling and simulating the nuclear plant Ringhals 3. The model should be used to improve the knowledge on the dynamics of the plant. Ringhals 3 is being upgraded to produce more power and a tool for analyzing the new operating conditions is needed.The work in this thesis has consisted of improving and developing an existing model of Ringhals 3 made with the modelling tool Dymola. The model has been validated by comparing the results of a simulated house load transient with data from the actual plant. Validation shows good agreement with data from the real plant.

Kvalitetsarbete i samband med byggande av betongkonstruktioner

The purpose of this thesis has been to develop a tool for modelling and simulating the nuclear plant Ringhals 3. The model should be used to improve the knowledge on the dynamics of the plant. Ringhals 3 is being upgraded to produce more power and a tool for analyzing the new operating conditions is needed.The work in this thesis has consisted of improving and developing an existing model of Ringhals 3 made with the modelling tool Dymola. The model has been validated by comparing the results of a simulated house load transient with data from the actual plant. Validation shows good agreement with data from the real plant.

Modellbaserad prediktiv reglering av en dieselmotor med variabel geometriturbin och återcirkulering av avgaser

Control of a diesel engine equipped with Variable Geometry Turbine (VGT) and Exhaust Gas Recirculation (EGR) requires a multivariable control method. One problem is that the engine system is non-linear. Furthermore there are strong cross-connections between inputs and outputs and the inputs have alsoboundaries. To be able to manage these control problems, MPC has been used that is a multivariable method. The MPC-controller consists of an optimization problem and therefore MPC can find the optimum control signals in an easy way.

Diesel Dubbelbränsle Teknologi

The work covered in this report includes a literature study of the diesel dual fuel technology(hereinafter referred to as DDF). The literature study covers earlier work that has been doneregarding the use of compressed natural gas (CNG) and diesel in a DDF system. Moreover a onecylinder research diesel engine was fitted with a CNG fuel system for experimental testing. Theinstallation of the engine and the test cell is described. Results from the tests are presentedcovering emissions, heat release and pressure traces from the DDF-concept.During the literature study it was found that most research was related to heavy duty dieselengines.

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