It is necessary to have an understanding of the reliability of water distribution network, in order to make right decisions on maintenance and expansion of an existing network. The purpose of the master thesis has been to find a method of assessing/estimating the reliability of a water distribution network. Reliability of a water distribution network can be regarded by the mechanical reliability of the components, and/or the networks ability to deliver water to recipients at a sufficient pressure, at both normal and failure situations. The later is hydraulic reliability of the network, and this has been the focus of this report. This report has focused on methods of measuring a water distribution networks ability to perform its required function, for mechanical failure events. There are two ways of regarding the hydraulic reliability of a network, one way is to preform impact calculations for the network and then regard average impacts as well as impact distribution and maximum and minimum impacts. The other way is to use the impact and combine the mechanical reliability of the components. The first way is regarded as assessment of the reliability, while the second method is estimation of reliability. When estimating the reliability of a network, it is necessary to use time intervals in order to get a good perspective. The report contains a suggested method for determining the reliability of water distribution networks for different time-spans, based on failure probabilities and impact assessments. The method that is suggested contains 10 steps, whereof 6 are considered necessary. The method has been tested using a skeletonized version of the actual network of Skullerud in Oslo, Norway as a case study. The case network was provided by the municipality of Oslo, and no changes have been made by the student. Failure rates for the network have been made from registered failures in the network of Oslo, for the period of 1975-2011. The impact calculations were done with two different software solutions, with varying degree of consistency between the different calculations. In addition the report also contains a short comparison of demand and pressure driven analysis, and how they impact results for supply criticality. It has not been found any clear indication of demand driven or pressure driven analysis, has in general a higher or lower impact on hydraulic criticality. There are large differences between how consistent the results are. Values for valves and pumps are quite consistent, while pipes are more varying. This is based on the case study. With regards to the case study, the method indicates that the network of Skullerud can be considered to be both mechanically and hydraulically reliable, and that the expected loss off supply for the network is less than 2%, given a single failure event. The expected number of failures for the network within a month is 4, with the majority having a low impact on the network hydraulics.

A synthetic jet is a flow control device which injects a pulsating jet flow of high-momentum fluid into a boundary layer near the wall confining a main flow. The technique is used to prevent or delay boundary layer separation. While the method is well reported for gas flows, less knowledge is available for liquid flows. It has been suggested that synthetic jets might be used in hydro turbines in order to stabilise draft tube flow. When accelerating a liquid flow, the energy consumption required will not only depend on the system mass, but also on the added mass due to acceleration of the liquid. The purpose of this thesis has been to study the physics of a synthetic jet where water is the working fluid, drawing special attention to added mass. CFD simulations have been conducted, where the synthetic jet was modelled using a dynamic grid. Results for added mass and frequency response of the system from CFD analysis have been compared to an analytic solution. CFD simulations seem to have captured a number of interesting effects not predicted from the analytic solution; the most prominent being frequency regions of lower added mass than analytically predicted. The apparent resonance regions are believed to occur due to interaction between the excitation frequency of the synthetic jet, and frequencies of dynamics in the system - examples are pressure pulsations from vortex shedding frequencies, or from frequencies originating from the effect of flow across a cavity. Furthermore, it has been demonstrated that operating the system at resonance will reduce the power requirements of the driving force, and that a variable stiffness spring should be part of the actuation system to allow for tuning of the resonance frequency.

Filament winding is a fabrication method for composite material structures, in which fibres are wound around a rotating mandrel. It is a versatile and dexterous process especially well-suited for creating and optimizing parts with a linear rotational axis. Products like pressure tanks, golf clubs or violin bows are commonly created using this technique. The winding itself is done through software solutions that generate a CNC program for the part in question. There are several such software solutions commercially available, all with different modes of operation and functionalities. However, they are also proprietary and offer little to no access into their inner logic. To optimise a part before production Finite Element Analysis software is often used. The part in question is modelled; material, forces and constraints are applied; and an analysis is run. Currently (June 2012), there are few options available for analysing filament wound products. Modelling a part with accurate filament winding layup generally has to be done manually, in a very time-consuming process. In this thesis, the author has performed a pilot study into the development of filament winding software. Software has been developed, capable of integrating both with a filament winding machine and with Finite Element Analysis software, and operating as a link between the two. The software has functionalities to extract geometrical variables from an Abaqus mandrel model; to write G codes and create a CNC program file; simulate a filament winding process in the Abaqus viewport; and, using a CNC program file, add accurate and corresponding layup to an Abaqus part. The main goal of this thesis, however, has been to create something that will serve as a basis from which others can continue development. The intention being that the software will be open source, so that anyone and everyone using it may change, improve and add on to it.

A Cartesian grid method has been developed for solving the 2D Euler and Navier-Stokes equations for viscous and inviscid compressible flow, respectively. Both steady and unsteady flows have been considered. Using a simplified ghost point treatment, we consider the closest grid points as mirror points of the ghost points. Wall boundary conditions are imposed at the ghost points of the immersed boundary. The accuracy of the method has been investigated for various test cases. We show computed examples of supersonic flow past a diamond-wedge airfoil and compare with analytical results. Further we compute time accurate solutions of the compressible Euler equations for an incident shock over a cylinder and compare the pressure time history with other work. The supersonic viscous flow around a NACA0012 airfoil is computed, and the lift and drag coefficients along with the pressure coefficient profile are compared with the literature. The method is also tested for supersonic flow over a cylinder, and the computed skin friction profiles have been used to assess the accuracy. Lastly the supersonic flow around a 2D F-22 fighter aircraft with simulated jet engine outflow is shown to illustrate the flexibility of the method. The present method is built on a previously established simplified ghost point treatment, but performs better. The results are comparable, although not as accurate as other more complex methods.

In the search for new technology, new materials are prerequisite for major breakthrough. One of these classes of functional materials is the metal-organic framework (MOF). The MOFs offer higher surface areas because of its porous structure and a potential for improved adsorption activity than other currently used materials. This makes it attractive for physical adsorption, which is a hydrogen storage technique. Adsorption type storage systems are alternatives that have the potential to reach the goals for handling hydrogen in on-board storage systems. However, the transient processes during charging and discharging of a storage system play an important role in the utilization of the hydrogen adsorption storage systems, and the heat distribution in the sorption material plays a major role during charging and discharging of a storage system. The specific heat capacity for activated carbon, Norit R0.8 (1), and three microporous MOFs, Cu-btc (2), Fe-btc (3), and MIL-100(Fe) (4), have been measured, both for inactivated and activated material. The compounds were measured using an MDSC method on a Q2000 differential scanning calorimeter with an appurtenant liquefied nitrogen cooler system (LNCS). The heat capacities were measured from -180°C to 150°C. The uncertainties for the different measurements were determined; it varied from 5% to 7%, depending on the assumed water content adsorbed. Further the measurement accuracy was found to depend very little on the inert gases present in the sample. In addition to measuring the porous material´s specific heat capacity, is it performed and presented a literature survey on theoretical models and published data for both gas adsorption and heat capacities in porous materials. The experimental results are compared with published data on reference materials where possible, and a complete uncertainty analysis on the experimental results presented. The inactivated sample curves showed a general trend, where the heat capacities for inactivated material normally were higher than the heat capacities for the respective activated material, which most probably was due to higher water content in the inactivated material. A considerable number of measurements on each material were performed, without obtaining the expected results for the activated samples. The principal reason was that an unexplainable transition around -150 °C was present on almost half of the obtained data. The exact reason behind this anomaly was not found. However, the most likely error was the activation of the samples, based on analysis and investigation of the results. This presumption was stated mainly because the heat capacities for the inactivated samples increased in a smooth and continuous matter with increasing temperature, without this sudden heat capacity change around -150 °C. The conclusion is due to the time perspective of this work an assumption based on observations and personal experience. Further investigation on the matter is recommended, especially to find out if there was a problem in the actual activation procedure or a chemical change in the investigated materials.

Mål Simulere Svartisen Kraftverk i LVTrans og sammenligne med frekvensresponsmålinger. Oppgaven skal bearbeides utifra følgende punkter: 1) Kandidaten skal sette seg in i teorien bak og metoder for frekvens respons målinger 2) Kandidaten skal delta i planlegging og utføring av målinger 3) Analysere data fra målingene 4) Modellere kraftverket i LVTrans 5) Utføre transiente simuleringer 6) Sammenligne resultat fra målinger og simuleringer, og identifisere og begrunne eventuelle avvik

Vannkraftlaboratoriet har i den siste tiden opplevd stor pågang fra eksterne firmaer som ønsker å teste modeller av turbiner og andre vannkraftmaskiner. Det er derfor ønskelig å kartlegge kapasiteten til pumpene i Vannkraftlaboratoriet. I denne oppgaven er det utført målinger av pumpene. På grunnlag av målingene er det utarbeidet en pumpekarakteristikk med virkningsgradskurver. Pumpene, to KSB 400-665, ble kjørt i singel-, serie- og parallelldrift, og det ble utarbeidet pumpekarakteristikker for disse konfigurasjonene. Det ble ved undersøkelser funnet at pumpekarakteristikken er stabil i alle områder. Det ble utført trykkpulsasjonsmålinger på pumpene og i rørsystemet for å se i hvor stor grad trykkpulsasjoner fra pumpene kan påvirke turbinforsøk. Av den grunn er pumpene kjørt i system med en høytrykks-Francis modellturbin. Pumpas løpehjulsfrekvens (turtallsfrekvens) og harmonier, samt løpeskovlfrekvens ble identifisert i trykkpulsasjonsmålingene på pumpa. Disse frekvensene dempes ut i systemet. Trykkpulsasjonsmålinger på turbinmodellens innløp viste en reduksjon av løpehjulsfrekvensen, mens harmonifrekvenser og løpeskovlfrekvensen elimineres. På grunnlag av disse observasjonene kan det slås fast at turbinforsøk ikke påvirkes av trykkpulsasjoner generert i pumpa.

Kaldnes HYBAS (Hybrid Biofilm Activated-Sludge) avløpsvann-renseprosess består av to prosesser som er relativt godt forstått: Aktivslam (AS) og Moving-Bed Biofilm Reactor (MBBR), biofilm med bevegelige bærere. Det finnes en stor del litteratur, men spesielt for Aktivslam, som beskriver virkemåten og dimensjoneringsprosedyrer for de to systemene. For HYBAS er det viktig å få kunnskap om hvordan biofilm interakterer med aktivslammet og å danne en metode for dimensjonering av en fullstendig HYBAS prosess. Professor Hallvard Ødegaard ved NTNU har foreslått en modell for HYBAS, formulert som en 15-stegs utregnings-prosedyre, delvis basert på erfaringsdata, men med vekt på å være logisk og intuitiv. Denne modellen er analysert for overenstemmelse med litteraturen. Små modifikasjoner som forbedrer nøyaktigheten og generaliserer modellen er foreslått. Modellen er implementert i et Excel regneark for å muliggjøre eksperimentering og videre utvikling av modellen. En analyse av enkelte komponenter av modellen mot data fra et pilot-anlegg er forsøkt, men med betydelige problemer. Noen gode overenstemmelser med modellen blir vist, men også sterke uoverenstemmelser med modellen blir identifisert, med forbehold.

Hensikten med denne oppgaven var å kartlegge spillvarmestrømmene på et aluminiumsverk, samt diskutere deres utnyttelsespotensialer. Det ble ansett som mest hensiktsmessig å ta utgangspunkt i Hydro Aluminium Sunndal. Hydro var villige til å samarbeide om dette med kriterie om at oppgaven må kunne være matnyttig for et NTNU-Hydro-prosjekt som omhandler utvikling av en rågassvarmeveksler. Å undersøke partikkelkonsentrasjon og partikkelstørrelsesfordeling i rågassen fra elektrolysen på Hydro Sunndal ble dermed en viktig del av oppgaven. Spillvarmestrømmene på Hydro Sunndal ble kvantifisert til 3,4 TWh per år. Av denne energien forsvinner 304 GWh/år med rågassen fra SU3 ved en gasstemperatur på omtrent 90C, og 673 GWh/år med rågassen fra SU4 ved en gasstemperatur på omtrent 110C. 977 GWh/år med spillvarme har derfor et middels stort utnyttelsespotensial. Energien er meget godt egnet for distribusjon med fjernvarme, men markedet for dette i nærliggende områder er meget lite. Elektrisitetsproduksjon kan bli aktuelt i fremtiden. Spillvarmestrømmene er hovedsakelig kartlagt med dataer fra ulike kilder på Hydro Sunndal, blant annet fra HERE-databasen og målinger gjort av laboratorieteamet på verket, samt et måleprogram for varmetapet gjennom en elektrolysecelles overflater, utført fra 28. til 30. april 2008 på Hydro Sunndal, med tilhørende beregningsmodell. Et måleprogram for rågassen fra elektrolyseceller ble utført på Hydro Sunndal i perioden 10. - 14. mars 2008. Støvkonsentrasjonen i rågassen fra 56 elektrolyseceller i SU3 ble målt til å være 363 mg/Nm3 med et standardavvik på 12 %. Dette avviker sterkt fra resultater fra målinger gjort av Hydro Sunndals laboratorieteam i perioden februar 2007 til januar 2008, hvor støvkonsentrasjonen er målt til 848 mg/Nm3 med et standardavvik på 15 %. Avviket antas i hovedsak å skyldes naturlige variasjoner i støvkonsentrasjonen i rågassen. Resultatene for partikkelstørrelsesfordelingen forelå ikke da oppgaven gikk i trykken. Anbefalt videre arbeid er analyse av partikkelstørrelsesfordeling i rågassen så snart de nødvendige data foreligger, et omfattende måleprogram for å kartlegge energibalansen til en elektrolysecelle, samt et måleprogram for å kartlegge partikkelkonsentrasjon og -størrelsesfordeling for rågassen fra Hydro SU4.

SINTEF and NTNU are planning to build a 150 kWth Chemical Looping Combustion (CLC) reactor system. This is new technology and the CLC reactor system is going to be one of the largest of its kind in the world. The technology is promising for CO2 capture in terms of energy efficiency and economics. To verify the design a Cold Flow Model, CFM, has been built. In the CFM no reactions take place, but it simulates the hydrodynamics of the 150 kWth CLC reactor system. The reactor system consists of two reactors exchanging solids in a loop. The two reactors are one air reactor, AR, and one fuel reactor, FR. Air is injected at different locations in the CFM to fluidize the solids and achieve the proper mass flows. The Cold Flow Model has been commissioned and an experimental campaign was executed. A series of experiments running each reactor singularly were performed. The rig seems to be functioning satisfactory and a minimum of plugging in the pipes were observed. The Cold Flow model has two cyclones that showed collection efficiencies at approximately 99 %. This is important to avoid emissions of solids from the future CLC reactor system, both for economic and environmental reasons. An investigation and mapping of the operating area of the reactors singularly and coupled was the target of the experiments. Correlations between operating velocity, total solid inventory, air distribution and flux were found. Appropriate flow regimes, meant to give good gas solid contact efficiency, and mass flow’s entrainments were achieved. The targets of a solid circulation rate of 2 kg/s in the AR and 1 kg/s in the FR were also achieved. Air is injected in the bottom of the reactors to fluidize the particles. This air is distributed through primary and secondary nozzles. The highest primary air percentage tested in the FR, 75%, gave the highest flux. In the AR 100% was tested, but 70% gave the highest flux. The last result is in contradiction with other experimental work in the area which says that 100% primary air should give the highest flux. After the mapping of the operating area of the single reactors it was possible to try to run the two reactors coupled. The divided loop seal was tested but led to a pressure short circuit and a large amount of the total solid inventory was lost out of the cyclones in a short time. The operation of a divided loop seal is probably possible, but seems difficult. The internal part of the loop seals were sealed to make the operation easier. The loop seals could then be operated as traditional loop seals. A challenge was the mass balance between the fuel reactor and air reactor. The mass flows of particles from both reactors must be equal to have a mass balance. Otherwise all the particles eventually ends up in one reactor. Results from the single reactor experiments were used to know approximately which operating conditions gave a mass balance between the reactors. The Cold Flow Model seemed to a certain degree be self regulating for achieving a mass balance if initial operating conditions were reasonable. Two experiments with coupled reactors and mass exchange only through the loop seals were done. A global solid circulation rate of 0.7 kg/s and 1 kg/s was achieved. Both AR and FR had the proper flow regimes. Proper flow regimes in the reactors are turbulent or fast fluidization. A third experiment utilized a lifter to enhance the solid transport between the reactors. A lifter is a additional transporter of solids from one reactor to another. The lifter worked successfully. The experiment had a global solid circulation rate of 1.4 kg/s. The mass flows were 1.4 kg/s from the AR loop seal and 1 kg/s from the FR loop seal. The remaining part 0.4 kg/s from the FR to the AR was transported with the lifter. Both reactors had proper flow regimes. A fourth experiment trying to achieve a global solid circulation rate of 2 kg/s failed. The bottleneck seems to be the AR loop seal. Solids accumulated and the loop seal was not able to handle this rate of solid flow. A new operation philosophy and design of the loop seal has been proposed. The new design of the loop seal and operation philosophy reduces the air flow needed in the loop seal, but it may not necessarily solve the solid circulation limit in the AR loop seal. Further investigation is needed. Manipulating the pressure in the AR may contribute to enhance the rate of solid flow through the loop seal. The successful experiments were presented at the 1st International Conference on Chemical Looping, IFP-Lyon, France, 17 - 19 March 2010. After the experimental campaign was finished the experiments were simulated with the fluidization software ERGUN developed by Compiegne University of Technology. ERGUN applies different mathematical models. For the simulations performed Horio’s and Berruti’s model were applied. The evaluation of the ERGUN simulations by means of the experiments shows that Horio’s and Berruti’s model should not be used for a detailed investigation of the flow structure in the CFM’s risers. However, despite its strongly empirical nature, a preliminary investigation of the riser’s behavior with Berruti’s model may be useful. Berruti’s model is a reasonable tool for modeling the upper part of the pressure profile in the AR and FR at the operating conditions tested. The operating conditions tested in the AR are total solid inventories of 35 and 45 kg, and superficial gas velocities from 0.9-1.9 m/s. The operating conditions tested in the FR are total solid inventories of 35 and 50 kg, and superficial gas velocities from 1.5-2.0 m/s. Berruti’s model is not capable of accounting for the dense bed in the lower part of the reactor as Horio’s model does. However, Horio’s model mismatched the experimental results too much. Horio’s model seems to be a provide a better match at larger total solid inventory and smaller operating velocities, hence flow regimes not relevant for the CLC reactor system.