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3118 Uppsatser om Engine control - Sida 2 av 208
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To achieve an optimal combustion, an even air/fuel ratio in the combustion chamber is required. An optimal combustion leads to reduced amount of emissions due to a more complete combustion, which is an important matter because of the sharpened environmental laws. This can be attained, among other things, by applying entirely variable cam times. To optimize the engines efficiency and its emissions at all workloads and speeds, an active valve control can be applied. This means that the intake and exhaust-valves can be opened and closed at any time, independent of the crankshaft position.
Utveckling av kyl- och smörjsystem för ekobilen Agilis HCCI motor
Every year, KTH participates in the Shell Eco Marathon, a competition whose goal is to design a vehicle that can go as far as possible using only the equivalent energy of one liter of petrol fuel. This year, one of KTH?s contributions to this race is the Agilis prototype; a car powered by a uniquely configured HCCI-engine developed at the university. The engine is dependent of several subsystems in order to work properly, among other, systems for cooling and lubrication.Combustion engines are in need of a cooling system that reduces the heat developed during the combustion. In general, two main types of cooling systems are employed; either air cooling, where the outside of the cylinder is exposed to a flow of the surrounding air, ore water cooling, where water flows in tubes around the engine, and the heat are transferred by the water to the surrounding air through a heat exchanger.The purpose of the lubrication system is to prevent the friction that builds up in the interference between moving parts in the engine.
Lingvistik och användbarhet i sökmotorer
This is a master thesis from Uppsala University in collaboration with B Locket AB (more known as www.blocket.se). B Locket AB is a large ad-company from Sweden, located in Stockholm.Search engines on the market today are becoming more and more complex. When they were first introduced, they only had one function and that was to produce search results containing the string that the user had typed. Today, users want it to be able to spellcheck, produce more results and sort search results on specific fields as well. Preferably, all these features should not affect the performance as a whole.The reason to why these demands have come up is that users are getting more and more used to internet services as a whole and they want everything to be as easy as possible.The user ability has become a substantially more important area in the computer industry and this needs to be taken into account when it comes to B Locket AB and its search engine.
Utformning av webbportal för tjänstlediga medarbetare vid Volvo Cars Engine och utexaminerade elever från Volvogymnasiet
This report describes the development of a web site for co-workers on leave of absence at Volvo Cars Engine AB and graduated students at Volvo Upper Secondary School in Skövde. The aim of the web site is to be a complement to existing communication channels in the promotion of the contact between the target group and the company. The work was divided into two parts; the first consisting of a preliminary study used to identify the information which the target group finds absent in their absence from their place of work/school, and the second part consisting of the development of a proposition of content layout and web site design. The finished proposition was presented along with a couple of alternatives for the technical implementation. The information department at Volvo Cars Engine AB in consultation with Volvo Cars IT will carry on the implementation, administration and further development of the proposed solutions..
Adaptive Charging System : Anpassningsbart laddningssystem för elbilar
This is a master thesis from Uppsala University in collaboration with B Locket AB (more known as www.blocket.se). B Locket AB is a large ad-company from Sweden, located in Stockholm.Search engines on the market today are becoming more and more complex. When they were first introduced, they only had one function and that was to produce search results containing the string that the user had typed. Today, users want it to be able to spellcheck, produce more results and sort search results on specific fields as well. Preferably, all these features should not affect the performance as a whole.The reason to why these demands have come up is that users are getting more and more used to internet services as a whole and they want everything to be as easy as possible.The user ability has become a substantially more important area in the computer industry and this needs to be taken into account when it comes to B Locket AB and its search engine.
Maskinrums design och layout : Varför ett maskinrum ser ut som det gör och hur det går till vid planerandet?
This report is founded in lack of knowledge concerning the design and layout procedureduring a new engine room construction.The prime question is how the engine room takes its form from idea to construction and whathappens in between. We want to give the reader a better understanding in how the work isdone and why it is designed the way it is concerning layout, ergonomics and safety. Duringthis report we will enhance the knowledge concerning regulations and rules that are of greatsubstance such as SOLAS, Swedish Sjöfartsverket and IMO.By contacting the parties involved in the process in newly designing a vessel and its engineroom, we will assume their approaches and experiences. We will study the work progressfrom planning to construction of a vessels machinery spaces. We will with the help ofinterviews with interested parties get an idea of the approach and also compare the finishedproduct a bit depending on company size and resources.The investigation resulted in a good basis for how a ship engine room design takes shape andwhich aspects are taken into account, however, we found that the existing rules concerningengine room layout was very vague and was seen as the most recommendations.
Adaptiv katalysatormodell för reglering
This master?s thesis describes the development of a model of the catalystsystem aiming at control by an MPC. A well functioning model, which is suitable in control purpose, is important while emission legislation become more and more hard to fulfill for the car manufacturers. Much research has been done in the field of physical modeling of the system, but in this work a linear adaptive time discrete ARX-model is developed and validated.The systems tendency to change its dynamic during usage implies that the model must be adaptive. The developed model proved to be well functioning and shows promising conditions for the MPC design.
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.
ESC-analys och studering av knack på en "Diesel Dual Fuel"-motor
A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated.At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NOxemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6.One issue with DDF is the high HC emission levels.
Direct-EGR tillämpat på HCCI
The Homogeneous Charge Compression Ignition (HCCI) engine is promising in terms of lowNOx, low particulates and high efficiency. Due to its homogeneous charge, where thecombustion starts almost simultaneously from a number of points in the combustion chamber,only lean mixtures are possible to burn because of the resulting rapid combustion, which is muchfaster than the combustion in an SI-engine or a diesel engine. When richer mixtures are used thecombustion will start earlier and also be more violent.To phase the combustion later and lower the combustion speed, external cooled EGR can beused. The EGR-system used in this thesis uses a divided exhaust channel where one channel andits corresponding valve are used only for transporting EGR back to the intake system.Consequently the EGR-valve is connected to the intake pressure. This system is called Direct-EGR (D-EGR).Engine tests verified that the CA50 indeed is phased later when cooled EGR is used.
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.
Konstruktionstudie av en ångexpander
This thesis applies to a novel steam expander, one part of a steam engine system, a wobble plateengine. The piston in the expander moves axially with the outgoing rotating shaft and is locatedon a plate, why the engine type is called axial engine. When steam is applied to the plungers theplate wobbles creating a rotation on the shaft going thru the wobble plate. The steam expander issupposed to be used in exhaust gas recovery (bottoming cycle) applications and small scaleenergy production. The commissioner is Ranotor Utveckling AB.
Utveckling av ny musiktjänst på Google App Engine
Idag använder många band och artister utan skivkontrakt olika tjänster på Internet för för att publicera sitt material. Dagens populära tjänster saknar antingen en välutvecklad musikspelare eller en webbplats med community.Syftet med det här arbetet är att med hjälp av molntjänsten Google App Engine, programspråket Python och ramverket Django utveckla en mer komplett tjänst.Arbetet resulterade i grunden till en tjänst samt en rad positiva och negativa slutsatser gällande valet av teknik..
Vätedriven förbränningsmotor : Klarläggande av framtida hållbarhet
Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These properties are both good and bad for combustion.
Zilent Ocean : EL-KONVERTERING AV INOMBORDSMOTORER TILL SEGELBÅTAR
Through extensive research it has shown that today?s sail boat owners are very frustrated concerning the limited choice of engine alternatives offered by today?s market. Besides rising fuel-costs, environmental awareness is very important in today?s society. Hence it is vital to find alternative environmental-friendly motors and replace combustion-engines. Zilent Ocean is an extensive project within Development engineering program at Halmstad University.