<p>In order to map the effects of blockage and aspect ratio, pressure distributions were measured around four different floor-mounted semi-circular cylinders in nominally two-dimensional flow. Diameters ranged from 0.05m to 0.30m for 0.3·10^5<3.5·10^5. No significant blockage effects were found for B=0.05. It was shown that by using the bulk flow velocity as the reference velocity, blockage and aspect ratio effects could be partially counteracted. The use of the bulk flow velocity was identified to be especially efficient in correcting the base pressure coefficient, but led to a larger variation of the minimum pressure coefficient with Re, for a given blockage ratio. Results also indicate that blockage is the governing factor of the base pressure coefficient for L/D>10, while the aspect ratio has the largest influence below this threshold. Separation bubbles occur in a manner similar to that of circular cylinders. The results do, however, indicate that the progression from laminar separation to purely turbulent separation may be accelerated by increased blockage. Further, the speed up over the cylinder was found to be approximately constant for a given blockage, and proportional to the square root of the blockage.</p>

<p>Two rigs have been developed and built to measure thermal conductivity and permeability for porous materials. The intention of the rigs is to investigate the properties of some hydrogen adsorption materials. The materials are only available in small volumes which have been taken into consideration under the development. Fourier’s law of heat conduction has been used as a basis for the development of the thermal conductivity rig. A cylindrical geometry with centered heater was chosen to ensure that all heat must be transported through the specimen. The temperature and heat distribution have been evaluated numerically to find the required insulation on top and bottom. Based on the chosen insulation, the rig is able to measure the conductivity for specimens with minimum conductivity of 0.1 W/mK. To make the rig capable of measurements at different temperatures, a side wall cooling system has been developed where fluid is transported on the outer side of the rig. Depending on the coolant fluid, the rig is capable of measurements within a wide temperature range. Liquid nitrogen and tap water have been used in the measurements where the lowest measurement was performed at -137degC. The uncertainties have been determined where the positioning of the thermocouples have been shown to be most affecting due to the small dimensions of the rig. The results have an uncertainty of +-10%. The permeability rig have been developed using the principles of Darcy’s law. To estimate the magnitude of the flow rate and pressure loss for a given material, a set of empirical equations has been used. Based on the estimations it turned out that great variations in pressure loss can be expected depending on the pore size diameter of the material. They also stated the validation of Darcy’s law which is for slow viscous flow only. The uncertainties in the equipment have been estimated and indicated that results can be obtained with an uncertainty less than 10%. The measurements pointed out that the geometry of the rig should be modified as the pressure loss turned out to be too small. Due to delays, the adsorption materials were not available when the rigs were ready for measurements; therefore, other materials were chosen to test the rigs. The permeability results has been compared to the estimation based on the pore size diameter of the materials. For the conductivity rig, the results were harder to verify since the properties such as porosity and conductivity of the solid phase not were known.</p>

<p>Numeriske simuleringer blir utført for å undersøke hvordan swirlstrømning kan bidra til trykktapsreduksjon over rørbend. Fire individuelle sammenligninger gjøres først mot publiserte eksperimentelle data av Eggels, Wu & Moin, og Anwer & So, hvor strømningene har fellestrekk med denne oppgaven. Dette av den grunn at det ikke eksisterer talldata for swirlstrømning i dobbeltbend, samt til den hensikt å skaffe til veie erfaring rundt oppsett av numeriske skjema og turbulensmodeller for denne typen strømning. Det gjennomføres simuleringer for swirltall 0.5 og 1, og for ordinær rett rørstrømning, for bendradier 0.75D, 1D, 1.5D, 2D og 3D, for henholdsvis Re = 63300 og Re = 316000. Det utformes også en intern statisk swirlgenerator med 6 blader og 102 graders vridning. Resultatene viser at det er en korrelasjon mellom swirl og reduksjon av trykktap, ved at innsnevringer og områder med tilbakestrømning, som oppstår i en ordinær rett rørstrømning, reduseres betydelig. Total trykktapsreduksjon sammenlignet med rett rørstrømning, oppnås best i rørsystemer med flere påfølgende bend. Det vises også at bevaring av tangentiell hastighet gjennom dobbeltbend i to plan er avhengig av swirlretning og rørgeometriens retning i forhold til denne.</p>

A series of former small scale experiments on unstable gas lift conducted at the NTNU multiphase laboratory have become subject to numerical simulations with two different multiphase one-dimensional flow simulators. In the experimental setup the injected gas accumulates in a riser inlet bend configuration and then discharges into the riser due to expansion driven flow acceleration in the riser. This gives a cyclic flow, resulting in unstable production with characteristics similar to those associated with density wave instability. No similar experimental contributions have been found in the literature. Simulations with and without slug tracking have been performed with the commercially available simulator OLGA. The simulations without slug tracking have been conducted on a fine grid with a cell length in the order of one pipe diameter, thus representing a slug capturing approach. The OLGA simulations with slug tracking have been conducted on a coarser grid. The SLUGGIT simulator is a non-commercial in-house NTNU slug tracking simulator based on a moving grid formulation. This simulator exists in several versions which are all implemented in C++ by use of object oriented techniques. One of these versions has been modified to handle a gas source at any location along the pipeline. Both OLGA without slug tracking as well as the SLUGGIT have proven capable of reproducing the unstable expansion driven flows shown inthe experiments.

Flerfasestrømning er et komplekst forskningsområde med mange usikkerheter. Kompleksiteten gjør at litteraturen består av mange modeller med vilt forskjellige innfallsvinker for hvordan fasefraksjoner, trykkfall og strømningsmønsteroverganger i slike strømninger skal modelleres. Forskjellene mellom disse modellene gjør at det er et behov for en enkel måte å sammenligne de med hverandre og med eksperimentelle data. I denne oppgaven er et rammeverk og et program som muliggjør slike sammenligninger planlagt, skrevet og dokumentert.Ved oppgavens start eksisterte det et program for MATLAB laget av en tidligere masterstudent for beregning av flerfase strømningsmodeller. Programmets funksjoner var nokså begrenset og kildekodens dårlige kvalitet gjorde det vanskelig å legge til nye modeller. Målet var derfor å lage et program og rammeverk fra grunnen av i C++ med større fleksibilitet, større grad av objektorientering og bruk av moduler. En tredeling ble derfor valgt med et hovedprogram som tar imot inn-data, sender disse til beregningsprogramtilleggene og viser resultatene, et sett med uavhengige programtillegg hvor alle beregninger foregår og til slutt et støttebibliotek for å koble sammen de to førstnevnte delene.Grensesnittene mellom hovedprogrammet og programtilleggene er slike at nye programtillegg kan utvikles uten endringer i kildekoden til hovedprogrammet. Etter at et programtillegg er lagt i korrekt mappe vil hovedprogrammet automatisk laste inn dette ved neste programstart og beregninger kan utføres med en gang.Fem forskjellige typer programtillegg for ulike beregninger er støttet, disse står for beregning av friksjon mellom fasene og veggen, slipp-forhold, utregning av regimeoverganger og beregningsmetoder for hvert av regimene. Resultatet er et fleksibelt program som raskt kan utføre mange typer beregninger og sammenligninger.

Denne rapporten fokuserer på en eksperimentell undersøkelse av fase inversjon for olje-vann blandinger. Undersøkelsen har blitt utført ved batch forsøk og direkte strømnings forsøk (uten å øke den dispergerte fasen), og både rå-olje og modell-olje har blitt brukt. Når modell-olje har blitt brukt, har også hydrofobe surfaktanter blitt brukt for å prøve å få oljen til å oppføre seg som en rå-olje og forsøke å kontrollere inversjons prosessen. Spesiell fokus har blitt rettet mot formasjon av multiple emulsjoner (w/O/W), og hvordan dette kan føre til fase inversjon. Visuelle bevis er presentert. Den første delen av denne rapporten er teoretisk, og inneholder den nødvendige teorien for å kunne tolke de eksperimentelle resultatene. Den inneholder også en beskrivelse av det eksperimentelle oppsettet som er brukt, og hvilke forsøk som er utført. Den siste delen av rapporten inneholder en seksjon med resultatene fra forsøkene. Denne delen inneholder trykkfall kurver, korde lengde målinger, visuelle bevis, og en samling av oppdagede, eller bekreftede relasjoner fra de utførte batch forsøkene. Resultatene er diskutert og konklusjoner er gjort, basert på det eksperimentelle arbeidet og eksisterende teorier. Resultatene er drøftet og det er konkludert med at fase inversjon kan skje i direkte strømnings forsøk med råolje (fra Grane feltet) som et resultat av at det dannes multiple emulsjoner over tid. Ved å bruke en korrekt mengde surfactant kan dette også skje når man bruker modell olje (Primol 352).Det blir også konkludert med at Cryo ESEM tekonologi kan bli brukt til å dokumentere formasjonen av multiple emulsjoner med større sikkerhet enn ved metoder brukt i tidligere arbeid forfatterne kjenner til.

Denne rapporten fokuserer på en eksperimentell undersøkelse av fase inversjon for olje-vann blandinger. Undersøkelsen har blitt utført ved batch forsøk og direkte strømnings forsøk (uten å øke den dispergerte fasen), og både rå-olje og modell-olje har blitt brukt. Når modell-olje har blitt brukt, har også hydrofobe surfaktanter blitt brukt for å prøve å få oljen til å oppføre seg som en rå-olje og forsøke å kontrollere inversjons prosessen. Spesiell fokus har blitt rettet mot formasjon av multiple emulsjoner (w/O/W), og hvordan dette kan føre til fase inversjon. Visuelle bevis er presentert. Den første delen av denne rapporten er teoretisk, og inneholder den nødvendige teorien for å kunne tolke de eksperimentelle resultatene. Den inneholder også en beskrivelse av det eksperimentelle oppsettet som er brukt, og hvilke forsøk som er utført. Den siste delen av rapporten inneholder en seksjon med resultatene fra forsøkene. Denne delen inneholder trykkfall kurver, korde lengde målinger, visuelle bevis, og en samling av oppdagede, eller bekreftede relasjoner fra de utførte batch forsøkene. Resultatene er diskutert og konklusjoner er gjort, basert på det eksperimentelle arbeidet og eksisterende teorier. Resultatene er drøftet og det er konkludert med at fase inversjon kan skje i direkte strømnings forsøk med råolje (fra Grane feltet) som et resultat av at det dannes multiple emulsjoner over tid. Ved å bruke en korrekt mengde surfaktant kan dette også skje når man bruker modell olje (Primol 352).Det blir også konkludert med at Cryo ESEM tekonologi kan bli brukt til å dokumentere formasjonen av multiple emulsjoner med større sikkerhet enn ved metoder brukt i tidligere arbeid forfatterne kjenner til.

The number of household gadgets that use energy, usually electricity, has multiplied in recent decades and energy use in a category that was long called “other” has risen significantly. In the mean time, another concern has arisen: the carbon cost related to the production and disposal of the gadgets. Investigating household electric and electronic equipment (EEE) as a specific household consumption category, the objective of this project is to get more understanding of their consumption and of their carbon footprint over there life-cycle. Space and water heating as well as lighting are excluded. The focus is on Norwegian household carbon footprint considering its specificities both in terms of consumption patterns, external trade and energy mix. First, an economic and statistical analysis of product ownership is conducted. It uses several data sources, such as the recent REMODECE campaign, sales data, lifetime estimation, EE-register data (registration of input and output of Electric and electronic equipment on the Norwegian market) and data from statistical office of Norway. Second, the project aims to record, analyze and compare different sources of information considering production and end-of-life. Both bottom up and top down approaches are investigated, even if a stress is put on bottom-up studies, such as ongoing European EuP study with its Ecoreport tool and EcoInvent database. Third it gives a best estimate of EEEs share in household carbon footprint, found to be 8,1% at 1,5 tons of CO2equivalent per household with production phase as a main contributor. A discussion on uncertainties assessing precision and identifying information gaps is also conducted. In addition to facilitate further research by setting up a framework grouping information sources critically analyzed, this project highlights the increasing importance of EEE products regarding sustainable consumption by putting numbers on the table.

<p>Abstract Motivation There is, at the present time, no submerged molasses pump on the market that is designed specifically for cargo tankers. Due to this I, find it interesting to look into the possibilities of installing a molasses pump in cargo tankers to transport molasses instead of transporting molasses in containers as it is done today. It is challenging to come up with a new product, and the motivation of actual be able to release a pump for the international marked is indescribable. Problem The goal is to make a prototype of a submerged pump specifically made for pumping molasses that can fulfill the customer requirements for flow and pressure. Obtaining reliable test result and demonstration of the pump is desirable before the new product is set into production. Approach Molasses is a very special and complex cargo, due to the complexity, 8cdot10^{3}kg of molasses was ordered from Australia. Then it was possible to do several tests on the actual molasses which the current market is for. Different pump designs have to be evaluated and then some design can be put into prototyping. The prototypes needs to go through several test so as much knowledge as possible can be gained before the pump is released on the market. Conclusion There is definitely a large market for transporting molasses by cargo tankers. There are already several orders for a molasses pumping system. Molasses seems to be a more complicated cargo pump then first assumed because of its big variations in viscosity due to temperature and different batches. There are many unknown factors involved in pumping molasses and as further it was dogged in to the problems new ones occurred. But the problems have been solved, some has been hard to solve. After three prototypes the customers requirements were finally achieved, and then all the hard work has finally given result. Even if the pump design is ready for the first order, many new question have arrived and this is the motivation to continue with the process that has already started. Especially interesting is the new technology that will be available next year regarding CFX a motivation factor to keep trying to rise the efficiency.</p>

<p>Increased knowledge of the degassing process in separation of gas from oil is important in connection with development of subsea separation and boosting units for heavy oil fields. The focus in the thesis is on theory and equipment design for two-phase separation of oil and gas. A review of gravitational separators and compact separation technology with a focus on subsea installations is given first. An extensive literature review related to theory governing the degassing process is further presented. The effectiveness of the degassing process depends on the gas’ ability to migrate out of the oil. Bubble dynamics theory, especially correlations for calculation of a bubbles velocity in a liquid is therefore examined. Bubble size, fluid properties, especially liquid viscosity, and gas volume fraction in the liquid is decisive factors for the bubble velocity. A comparison of several correlations obtained in various literature is made to determine the best available for modeling degassing. Most of the correlations have a limited range of validity in terms of bubble size and Reynolds number. It is verified that they are highly inaccurate outside this range. A correlation developed to be valid for a large range of bubble sizes seems to predict bubble velocities reasonably well. Because of its large range of validity, this is chosen to be used in the development of a separator model. Some experimental work is performed on two liquids with different viscosity. It is verified that separation of gas in viscous liquids requires significantly more retention time for the smallest bubbles reach the liquid surface. Occasional deviations from the examined theory are observed, especially for the more viscous liquid. Based the chosen correlation for bubble velocity a simplified model for horizontal and vertical gravity separators is developed. Separator size, fluid properties, flow rate and distribution of bubbles are input parameters. The model calculates how much of the initial gas volume fraction that remains in the liquid after separation. Consequence of high liquid viscosity and distribution of bubble size and bubble distribution in the liquid are evaluated by use of the model. When the oil becomes very viscous is it important that separator and internals are designed to optimize the conditions for degassing. This implies among others an inlet device which provides an ability to control the bubble distribution and keep the size of bubbles as large as possible. Methods are suggested for increased effectiveness in degassing of heavy oils, by reducing viscosity, increase the coalescence rate and affecting the flow pattern. Separation of other phases and undesirable components is also important and may make it difficult to optimize the design for the degassing process. However, a separator should be efficient in all respects, making knowledge of the degassing process anyhow important. The thesis gives an overview of important parameters in the degassing process. Much work still remains to develop correlations and models which can give a more exact description of real systems. Continuous development in separator components and not at least compact separation technology is important to effectively be able to produce heavy oil, especially in terms of subsea installations.</p>