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487 Uppsatser om Google App Engine - Sida 7 av 33
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.
Utformning av konst- och musikhus med läge i unik miljö
Examensarbetets mål var att utforma två förslag på ett musik- och konsthus för placering i Växjösjön. Konstruktionen ämnas vara flytande och mobil.Gemensamt undersökte författarna byggnadens förutsättningar och möjligheter, i syfte att underlätta utformningsprocessen.Författarna utformade var sitt förslag. Det resulterade i två förslag med skilda arkitektoniska särdrag, skapade utifrån gemensamt stipulerade avgränsningar.Det ena förslaget är utformat med hjälp av geometriska former med raka sidor. Det kontrasterar mot det andra förslaget som har organiska och mjuka former..
Reglerstrategi för fria ventiler : ? Utveckling av en fyrtakts förbränningsmodell för att prediktera optimala ventilinställningar
As emission legislations across the world continuously pushes engine development forward,engineers constantly need to come up with and implement fuel saving technologies. During thelast decade, variable cam phasing has become a popular solution to increase gas exchangeefficiency. This configuration is typically mechanically constrained by camshaft limitations, anda solution to circumvent this problem would be to use a different valve actuation principle.One example of this is to use pressurized air controlled by electrical solenoids. Such a systemhas been developed byCargine Engineering and this provides the starting point for this work. Tobe able to operate the valvetrain on an actual engine, a control system is needed.
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.
Folkbibliotekariers användning av sökverktyg på webben i referenstjänst
The web is a constantly growing medium that presumably plays an increasing role in public library reference services. In order to provide high quality reference service the librarians need to be able to master this medium. Therefore it is interesting to get an understanding of how librarians actually use the web. The aim of this Master s thesis is to investigate what web search tools are used by public librarians in reference service. Furthermore, the aim is to get an understanding of how the librarians think about those tools and what background factors influence their selection of tools.
Effekten av discoverytjänster på bibliotekens e-resurser? ? En undersökning om Summons effekt på Chalmers bibliotek.
The purpose of this essay is to examine what happens with library e-resources after implementing the discovery tool Summon. Summon provides a Google-like experience and uses multiple facet options when users need to narrow their discovery. Observations of change in the libraries e-resources with regards to database searches, click-throughs in linkresolvers and full text downloads are examined through looking at earlier reports and statistics from libraries in America and England. This provides a way to compare with Chalmers University of Technology?s Library.
DNS prestanda
Use of computers and computer networks is nowadays a part of everyday life. You do not use them only at home when you sit at you computer, but you can use them all the time everywhere. This can involve everything from surf to any website when you are at home, to checking your email on your mobile when you are on your way to work. Most people do not think about how it really works when they try to access a web page by typing the address into their browser, but something that most people probably notice is how long it can sometimes take to access a web page.All items which are directly connected to the IP network have a unique IP address that is used to make it possible to communicate. The IP address is either a period separated sequence of digits representing 32 bits or a colon separated sequence of digits representing 128 bits, depending on whether the address is an IPv4 or IPv6 address.
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..
Smartphoneapplikationer ? ett värdeskapande verktyg? : I bank- och livsmedelsbutiksbranschen
The smartphone market is growing rapidly, between Google Play and App Store more than 25 billion apps have been downloaded since 2008. Today many companies develop their own smartphone applications (apps) for their customers. We believe that many apps are developed without much consideration about the actual value it brings to the customer, and through them, value for the company. Instead they create applications with hope of keeping the company modern. Developing and implementing apps in a business is neither easy nor free and must therefore add value to the business in some way.
DATAKONSUMTIONEN I EN GWT-APPLIKATION : En jämförelsestudie mellan en webbapplikation skriven i GWT och en traditionell webbsite
Det finns flera anledningar till att minimera datamängden som överförs då en webbplats besöks. Ökad responsivitet och avlastning vid svåra förhållanden är två av dem. I denna rapport utforskas huruvida en webbapplikation, skriven i GWT och som använder sig av AJAX kan minska datakonsumtionen jämfört med en traditionell webbsite. Detta undersöks genom att två identiska webbplatser med avseende på innehåll och struktur skapas men som skiljer sig i hur webbsidorna byggs upp. En webbsite sammanställs i webbservern och skickar webbsidor till webbläsaren, en GWT-applikation skapar webbsidorna m.h.a.
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.
Studentdrivna onlinediskussioner i högre utbildning - En studie om skolrelaterade diskussioner på Facebook, Google Wave och IRC
Studier på universitetsnivå omfattar oftast mycket eget ansvar och individuellt arbete. På samma gång hörs röster om kollaborativt lärande och gruppkognition där studenter lär bättre när de arbetar tillsammans. I min förstudie intervjuas 4 studenter på det systemvetenskapliga programmet vid IT-universitetet i Göteborg om sitt laptopanvändande i skolan. I intervjun framkommer de att många av studenterna i årskursen på eget initiativ startat kollaborativa mötesplatser för att kunna arbeta och diskutera tillsammans med sina klasskamrater online utan lärares interaktioner. Efter vidare undersökning framkommer det att sådana mötesplatser finns hos alla de tre årskurserna på det systemvetenskapliga programmet.
Biogas till kraftvärme på Wapnö : en projektanalys utifrån ett företagsekonomiskt perspektiv
Biogas is a gaseous fuel, rich in methane, produced through a biological route in an anaerobic digester. A gas engine generates combined heat and power, which can be used at the farm to reduce energy cost. The process also generates a digestate, with better utilization of nutrient compared to cattle manure.
The aim of this study is to analyze the profitability of a farm-scale biogas plant for combined heat and power (CHP) at Wapnö. Wapnö is an agriculture company located in the southern part of Sweden.