No description available.

No description available.

As a part of the hydropower expansion in China, the Baihetan Hydropower Station is now being constructed in the southern parts of the country. This hydropower station will, when completed, become the third largest in the world in terms of installed power output.The construction of a hydropower plant of the Baihetans Hydropower Station’s size is not without problems and high standards of safety are essential as large land areas upstream and downstream of the dam are affected. One of the risks is that the flow of water through the dam can cause scour and erosion downstream of the dam which threatens the stability of both the dam and the riverbed. To evaluate this risk, studies of a model in the scale of 1:100 have been performed at the Department of Hydraulic Engineering at Tsinghua University in Beijing, China.This thesis evaluates whether the discharge through the dam causes a hydrodynamic pressure above the allowed limit in the plunge pool below the dam and which measures that can be made to reduce this pressure. Flow velocity measurements were conducted, both in the plunge pool and along the downstream riverbed, to further evaluate the risk of erosion.The experiments show that the use of nappe splitters in two of the surface spillways will reduce the hydrodynamic pressure in the plunge pool to well below the acceptable limit of 15 m H2O. However, the flow velocity downstream of the plunge pool is too large and protection measures are recommended to avoid riverbed erosion.The results obtained indicate that a shortening of the plunge pool is possible which would lead to a reduced construction cost. However, further studies would be necessary to determine if this increases the risk of erosion in the downstream river.

Detta examensarbete har gått ut på att finna en ny konstruktionslösning på uttlopps-diffusorns inloppsrör på gasturbin SGT-800. Arbetet har utförts på Siemens Industrial Turbomachinery AB i Finspång på avdelning RCTD (gasturbinkonstruktion). Målet med projektet har varit att ta fram en konstruktionslösning som underlättar för svetsmontörerna på site när det gäller installation av inloppsrören, samt reducerar monteringstiden. Målet har även varit att ta fram en kostnadsjämförelse för totalkostnaden mellan den nya och originalkonstruktionen. Den metodik som har använts till detta arbete är Voice of the customer samt Systematisk konceptutveckling som baseras på bl.a. Vladimir Hubkas princip. Även original-konstruktionen har undersökts via ritningar och bilder tagna från tidigare sitemontage. Originalkonstruktionen skickas idag till site omonterad tillsammans med utlopps-diffusorn direkt från SIT AB:s underleverantör KSG AB i Surte för att sedan monteras och svetsas fast på site. P.g.a. att inloppsröret måste monteras i vinkel samt att utloppsdiffusorn är rund till formen, måste svetsning idag ske med elliptisk hålpassning. Detta leder till att det är svårt att få rör och hål att passa ihop utan att modifieringar måste göras på något av dessa. Via intervjuer och brainstorming skapades 17 olika koncept, varav nio togs vidare för utvärdering med hjälp av de kundkriterier som tagits fram. Denna utvärdering resulterade i att sex koncept gick vidare till ytterligare en utvärdering, där slutligen tre koncept plockades bort. Genom jämförelse mellan de tre kvarvarande koncepten, valdes slutligen ett vinnande koncept. Det nya konceptet består av två rördelar där det övre röret har samma innerdiameter som det nedre rörets ytterdiameter. Detta ger montörerna möjligheten att justera rörets höjd och dess vinkelpassning till den bälg som sammankopplar inloppsröret med avtappningsröret. Den övre rördelen har svetsats fast på utloppsdiffusorn före transporteringen till site. För att montera ihop dessa rör krävs det att de svetsas ihop. Detta var ett monteringssätt som montörerna ville undgå. Dock har detta lösts genom att kapa de båda rördelarna så att passning och svetsning sker på runda mynningar. Det kommer även med största sannolikhet finnas möjligheter att minska rörets diameter, vilket minskar rörets totala vikt. Den nya lösningen kommer uppskattningsvis att reducera installationstiden på site med upp till 60 % jämfört med originalkonstruktionen. Detta kommer att ge en installationskostnad proportionellt minskad mot installationstiden. Det övre rörets installationsbehov före sitetransport kommer att generera en tillverkningskostnad som uppskattningsvis förblir densamma som för originalkonstruktionen. Den totala kostnaden för den nya konstruktionen kommer att minskas med ca 45 % jämfört med originalrören. Förhoppningen är att detta projekt genererat ett intresse hos SIT AB att gå vidare och göra en konstruktionsförändring på denna komponent, för att underlätta vid framtida montage. / In this examination paper, the bleed air inlet pipe on the exhaust diffuser for gas turbine STG-800 has been redesigned. The project has been performed at Siemens Industrial Turbomachinery AB in Finspång at the design department for gas turbines, RCTD. The aim for this project has been to develop a solution that makes it easier for the welders to mount the inlet pipes at site and to decrease the time for mounting. Another aim for the project has been to make a comparison of cost between the original design and the new design. The methodology that has been used in this thesis is the Voice of the customer table and Systematic design based on Vladimir Hubka’s design process, among others. There have also been studies of the original inlet pipe design by looking at drawings and pictures from former site mountings. Today, the original inlet pipe is shipped unassembled together with the exhaust diffuser direct from KSG AB in Surte, one of SIT AB’s subcontractors, to be mounted and welded on site. Due to the angled mounting caused by the design of the inlet pipe and the round exhaust diffuser, today’s welding must be made on an elliptic hole. This results in poor fitting of the inlet pipe and the hole and modifications have to be made to make them fit together. To find a new design for the inlet pipe, 17 concepts was created from interviews and brainstorming. Of those, nine was singled out and further evaluated by the developed criterions of the customer. This evaluation resulted in rejection of three more concepts. Last, the three maintaining concepts were compared and one final concept was selected. The new concept consists of two pipes. The upper pipe has the same inner diameter as the outer diameter of the downer pipe. This brings the opportunity for adjustments in height and angle to fit the bellow that does connect the inlet pipe with the bleed air pipe. The upper pipe has been welded on to the exhaust diffuser before it was shipped to site. To mount these two pipes together, they must be welded, even if the assemblers hoped this type of mounting would be avoided. This has been solved by designing round pipe endings. It is also most likely possible to make the design with reduced diameter, which will decrease the weight of the product. This new design will approximately decrease the mounting time on site up to 60 % in comparison with the original design. This will result in decreased installation cost. Due to the upper pipe’s need for mounting before it is shipped to site, the manufacturing cost will approximately be the same as for the original pipe. The total cost for both pipes will be decreased with approximately 45 %, compared to the original pipes. Hopefully, an interest has been generated at SIT AB by this project to make a change of the design for this component, to make the mounting easier in the future.

This project has been assigned for the thesis group by one of the leading Swedishconfectionery company Cloetta AB, and the main goal of this work has been to investigate“What feelings trigger more chocolate in wafer-based chocolates” with chocolate consumers.The Kansei Engineering study was used to achieve this and should deliver useful informationfor the market research and the development department at Cloetta AB.The Kansei Engineering methodology origins in Japan and is about gathering and analyzinginformation from the customer impressions and feelings about a certain product. Gatheredresults considering the physical properties and customer’s impressions are analyzed in relationto each other through various statistical methods.In practice this project has been executed through planning and performing surveys onchocolate consumers and the gathered data has later been analyzed accordingly to the KanseiEngineering Methodology. Statistical methods such as factor analysis using the statisticalsoftware SPSS and regression analysis using QTI through KESo software have been utilizedfor the analysis.In the factor analysis the so-called Kansei-words, which describe impressions of the waferbasedchocolates, were reduced from twenty to five words; preferable, lifestyle, disadvantage,rewarding and quality. These words were connected with the properties given from CloettaAB; number of wafers and amount of chocolate; and used in the final survey. The factoranalysis also included benchmarking of several competing products within wafer-basedchocolates.The final survey resulted in nine varieties of chocolate samples, all with varieties in thenumber of wafers and the amount of chocolate. Input data from this survey was handledwithin KESo software and analyzed with the QTI method.The results were comprehended and interpreted in text format and delivered to Cloetta AB.From the QTI results it may be concluded that feelings which trigger more chocolate amountin wafer-based chocolates are preferable, rewarding and quality.

<p>Guazuigua is a small village in Bolivia, which has had too small water resources, especially for irrigation. A project started after some studies were made, to create a canal to provide the village with water from a nearby town. To make the canal work it had to cross a dried out river. There have been several attempts to cross these dried out rivers, but with poor results. The purpose of the report is to provide a solution for this problem. During the field studies, the project changed direction, and a decision was made to build a well system instead. This proved to be a better solution for the village’s water problem. The report still remained with solving the canal problem. Calculations show that a pipe placed across the dried out river would break down. The report suggests a support construction which resembles a cable stayed bridge, which is build economical and by materials accessible in the area.</p> / <p>Guazuigua är en liten by i Bolivia som länge haft för liten tillgång på vatten, och främst i bevattningssyfte. Efter att en förstudie gjorts startades ett projekt att med ett kanalsystem förse byn med vatten från närliggande stad. Projektet finansieras av en personlig gåva. För att kanalsystemet skulle kunna genomföras behövdes en akvedukt byggas där kanalen är tvungen att passera en uttorkad flodbädd. Metoder att leda vatten över dessa flodbäddar har gjorts på ett flertal platser i området, där konstruktionerna havererat. Rapportens syfte är att bidra med en lösning på detta problem. Mitt under fältstudien förändrades projektets inriktning, varav man valde att bygga ett brunnsystem istället. Denna förändring var en bättre lösning på byns vattenproblem. Rapporten kvarstod ändå vid att lösa problemet med akveduktkonstruktionen. Beräkningar visar att ett fritt liggande rör över flodbädden skulle plasticera och haverera. Rapporten föreslår en stödkonstruktion som liknar en kabelupphängd bro, som är byggd på material som är billiga, och finns tillgängliga i området.</p>

<p>This thesis focuses on the structural behavior of a washer machine cylinder. The cylinder is the component in the washing machine that rotates and keeps the laundry in place. The aim of this thesis is to determine the maximum load applied to the cylinder at which crack propagation occurs. Three experiments are performed to determine the structural behavior of the cylinder. Two experiments are performed to estimate mechanical properties i.e. stress-strain relation and critical fracture energy of the stainless steel sheet in use today. This is to derive a good estimation of the maximum load the cylinder can endure. The third type of experiment is performed to determine the strains on the outer surface of the cylinder when an evenly distributed load, 11 kg, and 2200 revolution per minute are applied on the inner surface of the cylinder. Three numerical models are performed from these three types of experiments which gives an estimation of the work to be done to propagate the crack at 15 kg and 2400 rpm. The question is if this load is overestimated to start crack propagation? This load is considerably higher than the washer machines operating speed.</p>

<p>Rapporten beskriver konstruktionsarbetet av det vertikala vindkraftverket V3 från prototyp till produkt. Det är det nystartade företaget Windforce som arbetar med att ta fram smarta hybridsystem där V3 är en del i konceptet. En serieproduktion av V3 är planerad till hösten 2010. V3 är klassat som ett litet vindkraftverk, har en rotordiameter på 3 meter och en kapacitet på 5 kW. Vindkraftverket kräver inget bygglov i Sverige och ska säljas till gemene man som vill bli självförsörjande på el. Denna rapport utgår från den befintliga prototypen, tillverkarens direktiv och myndigheters krav för att produkten ska bli så bra som möjligt. De områden som berörs är konstruktion, FEM beräkningar och certifiering. Den internationella vinklingen på rapporten belyser möjligheterna och användningsområden för V3 i utvecklingsländer med bristande infrastruktur. Förändringar på konstruktionen görs för att förbättra till exempel, luftfolier för bättre effektivitet och vajrar mellan ekrarna för att stärka hållfastheten. Dessutom görs det vissa standardiserade detaljer för att sänka tillverkningskostnaderna. Lager till vindkraftverket väljs för att bättre passa konstruktionen och delar av CE-märkningen görs.</p>

<p>A modern diesel engine is capable of running efficiently with low exhaust gas emissions over a wide operating range. This is thanks to techniques such as turbocharging, EGR, charge air cooling and an advanced fuel injection process. The fuel injection process is important for the combustion and emission formation in the diesel engine. The fuel injector has to atomize and vaporize the fuel as it is injected. During the combustion the emission formation has to be kept to a minimum. Very strong pressure gradients are present in a modern diesel injection nozzle, this causes cavitation to occur in the nozzle holes. The influence of cavitation on flow parameters such as the various discharge coefficients is discussed. The occurrence of cavitation helps the spray break up and it can keep the nozzle holes free from deposits. Excessive amounts of cavitation can lead to hole erosion and thus impact the long term operation of the nozzle in a negative way. Hole erosion as well as other mechanisms can cause hole to hole variations in fuel spray impulse, mass flow, penetration etc. This is a very important issue in any low emission diesel engine, especially during transients, as less than optimal conditions have to be handled. The influence of hole to hole variation on fuel consumption and emissions is not very well known and this thesis contributes to the field. As a part of this work a fuel spray momentum measurement device was developed and tested. Any automotive engine needs to be able to perform quick transitions between different loads and speeds, so called transients. In a turbocharged diesel engine with EGR issues related to the turbocharger and the EGR-circuit arise. A diesel engine has to run with a certain air excess in order to achieve complete combustion with low emissions of soot. When turbocharging is used the turbocharger turbine uses some of the exhaust enthalpy to drive the turbo compressor, in this way the engine is provided with boost pressure. In order for the engine and turbocharger to function at the higher load and thus higher mass flow rate the turbocharger has to increase its rotational speed and the surface temperatures have to settle at a new thermodynamic state. Both of these processes take time and during this time the combustion process may have to proceed under less than optimum circumstances due to the low boost pressure.</p>

No description available.