Det finns idag behov av att ta fram information om hur vatten flödar i marken. För att undersöka detta brukar det installeras grundvattenrör. Grundvattenrör används oftast i syfte att bevaka grundvattennivåer i marken men kan även användas för att utföra hydrauliska tester vars syfte är att skatta jordens hydrauliska egenskaper. Det är då framförallt den hydrauliska konduktiviteten som söks. Kunskap om markens hydrauliska konduktivitet är bland annat viktig för modellering av grundvattenflöden och beräkning av föroreningsspridning. Genom åren har det utvecklats ett antal hydrauliska tester för att ta fram hydrauliska egenskaper i jorden. Från de ursprungliga testerna med pumprör och observationsrör (interferenstester) har det tillkommit metoder för att genomföra tester i enskilda grundvattenrör. Idag kan bland annat pumptest och slugtest genomföras för att skatta hydrauliska egenskaper i enskilda grundvattenrör. Examensarbetet har undersökt olika hydrauliska tester som genomförs i enskilt grundvattenrör. Testerna har varit pumptest, injektionstest, slugtest med solid slug, slugtest med vatten och stigningsmätning. Testerna har genomförts i 11 olika grundvattenrör. Grundvattenrören har varit placerade i olika jordarter och akvifertyper. Alla tester har gjorts i alla rör för att kunna göra en jämförelse mellan testerna. Resultat från testerna visar att det föreligger en variation i skattade hydrauliska egenskaper när en jämförelse gjordes mellan alla slugtester och alla pumptester. Pumptesterna gav generellt en mindre variation mellan test och modellösning och visar sig därför mer oberoende av testtyp och val av modellösning. Slugtesterna visade skillnad i skattad hydraulisk konduktivitet beroende på modellösning. Modellösningarna Hyder mfl. (1994)/KGS och Dougherty-Babu (1984) för slugtest gav en högre skattning hydraulisk konduktivitet än pumptesterna medan modellösningen Bouwer-Rice (1976) gav en lägre skattning av hydraulisk konduktivitet än pumptesterna. Testerna skiljer sig åt när de genomförs i olika jordarter. I lågkonduktiva jordarter är det svårt att genomföra olika typer av pumptest då dessa är påverkade av brunnsmagasin och det krävs att pumpflödet är tillräckligt lågt för att grundvattenröret inte ska torrläggas eller svämma över. Därför är det rekommenderat att utföra slugtest i lågkonduktiva jordarter. I högkonduktiva jordarter är det rekommenderat att göra pumptester då slugtester genererar färre mätpunkter och kan därför leda till fel i modelleringen. / There is a need today to gain information on how water moves in the ground. Groundwater pipes are therefore installed to monitor the groundwater levels. These groundwater pipes can however be used to perform hydraulic tests to obtain information regarding hydraulic properties of the soil. Hydraulic tests are usually performed to investigate the water flow in the soil. This water flow is called hydraulic conductivity. Information on hydraulic conductivity is, for example, essential in modeling of pollutant transport. Several types of hydraulic tests have been developed throughout history in the purpose to investigate hydraulic properties in the soil. The original tests involved pumping tests where one pipe was pumped while an adjacent pipe was used to monitor water level changes. From these original pumping tests there has been a development where the methods can be applied in a single groundwater pipe. Typical single-well tests used today are pumping tests and slug tests. This thesis has investigated and evaluated different hydraulic test performed in single groundwater pipes. Two types of pumping test have been performed: pumping test with constant flow, where the water is pumped out from the pipe, and injection test where water is pumped into the pipe with a constant flow. Three types of slug test have been performed: slug test using a solid slug, slug test using water and rising head test. Slug test is a test where the water level in the pipe is rapidly lowered or raised. The time it takes for the water to return to the initial water level is measured and used to calculate the hydraulic conductivity of the soil. The tests have been performed in 11 different groundwater monitoring pipes. The groundwater pipes were situated in different types of soil and aquifers. All the tests were performed in all the pipes to be able to compare them. Different model solutions were used to analyze the measured data from the hydraulic tests. The results showed variation in estimated hydraulic conductivity when the average hydraulic conductivity of pumping tests and slug tests were compared. The different types of pumping tests had on average a small difference in hydraulic conductivity and the results were on average independent of model solution used. Depending on the model solution there was a difference in hydraulic conductivity for the slug tests. The model solutions of Hyder et al (1994)/KGS and Dougherty-Babu (1984) for slug test estimated over-all a higher hydraulic conductivity than the pumping tests while the model solution of Bouwer-Rice (1976) estimated over-all a lower hydraulic conductivity than the pumping tests. The results and performance of the tests behaved differently depending on the type of soil. It was difficult to perform pumping and injection tests in low conductivity soils due to well-bore storage in the groundwater pipe. It is therefore recommended to perform slug tests in low conductivity soils and pumping tests in high conductivity soil because slug tests generates fewer measurements than pumping tests and can cause errors in the modeling.

Continuous processing in the pharmaceutical and fine chemical industries, particularly in micro/milli-scale reactors, has been a topic of interest in literature in recent years due to the advantages offered over batch reactions. One such advantage is the enhanced transport properties of operating at smaller scales, although the quantification of the transport phenomena is not straightforward when wall and entrance effects cannot be neglected. In the first study presented, various micro-mixer geometries and scales were considered to increase the mixing efficiency in liquid-liquid systems of diverse interfacial tensions for fast reactions. The conditions were varied over different flow regimes; including slug flow, parallel flow, and drop flow. A mass-transfer-limited test reaction was used to evaluate the overall volumetric mass transfer coefficients (Korga) as a function of the average rate of energy dissipation (ε) for each mixer design. The onset of drop flow occurred at a lower ε for the LL-Triangle mixer when compared with the Sickle or LL-Rhombus mixers for low interfacial-tension systems (i.e., n-butanol-water). In the drop flow regime for energy dissipation rates of around 20 to 500 W/kg, Korga values ranged from approximatively 0.14 to 0.35 s-1 and 0.004 to 0.015 s-1 for the relatively low and high interfacial-tension (i.e., toluene-water) systems, respectively. The second investigation explored the heat transfer properties of a FlowPlate® system by Ehrfeld Mikrotechnik BTS. First, in a non-reactive system with rectangular serpentine channels (d_h<1mm, 400<Re<2000), a Gnielinski-type model was fit to the internal Nusselt number. Using a silver-based thermal paste between the reactor and heat transfer fluid plates proved to reduce the external resistance to heat transfer by ~70%, yielding overall heat transfer coefficients of ~2200 [W/(m^2 K)]. Secondly, a Grignard reaction was highlighted as a test reaction to compare different reactors’ localized heat transfer characteristics (i.e., hotspot formation) with various micro-mixer geometries, materials, injection ports, and channel scales. Lastly, a case study of four reactions utilized the fourth Damköhler number to determine a maximum channel diameter that would remove sufficient heat to avoid hotspot formation. Each of these studies provides insight to aid in the proper selection of a reactor for a given set of physical properties and reaction kinetics/enthalpies.

<p>To fully realize the advantages of the two-fluid model, the interfacial area concentration (IAC) should be properly given by a constitutive model. The conventional flow-regime-based IAC correlations intrinsically cannot predict the dynamic flow structure change and would introduce a discontinuity and numerical instability to system codes. As a promising alternative, the interfacial area transport equation (IATE) is developed to model the interface structure mechanistically. Progress has been achieved for IATE modeling in bubbly, slug, and churn-turbulent flow during the past two decades. Aiming at a comprehensive flow structure predictor for all flow regimes, further development in two directions is highly desirable. First is extending the current experiment and modeling capability from churn-turbulent to annular flow. In this study, an advanced four-sensor droplet capable conductivity probe (DCCP-4) is developed to capture all interfaces in churn-turbulent and annular flow, including liquid film, liquid droplet, gas core, and gas bubble. A first of a kind experimental database in churn-turbulent, annular, and wispy annular flow with two-dimensional spatial distributions is established, which provides the experimental basis for the multi-field two-phase flow model development. The measured parameters include local time-averaged volume faction, IAC, and velocity for various fields of annular flow. In addition, a new constitutive model to quantify the interfacial area between the gas core and liquid film of annular flow is developed, which fills the last theoretical gap of interfacial area modeling. The other important direction is improving the current IATE model to fulfill the dynamic prediction of developing flow, especially the bubbly to slug transition flow. Vertical-upward air-water two-phase flow experiments are performed. The state-of-the-art IATE model is evaluated against the newly collected data at bubbly and slug flow, and the result shows unsatisfactory performance in predicting the developing flow with intensive bubble coalescence. A new bubble coalescence model is derived by using the log-normal bubble size distribution, which significantly improves the model prediction capability.</p>

Für die Untersuchung von Luft/Wasser-Strömungen wurde ein horizontaler Acrylglas-Kanal mit rechteckigem Querschnitt gebaut. Der Kanal ermöglicht Gleich- und Gegenstrom-Versuche bei Atmosphärendruck, insbesondere die Untersuchung der Schwallströmung. Es wurden optische Messungen mit einer Hochgeschwindigkeits-Kamera durchgeführt, die durch synchronisierte dynamische Druckmessungen ergänzt wurden. Für die Analyse der Bilder wurde eine Methode zur Erfassung der Phasengrenze entwickelt und diese anhand möglicher Anwendungen getestet. Die Druckmessungen zeigten, dass der Druck bei Schwallströmungen um einige Kilopascal ansteigt und wieder abfällt, sobald der Schwall aus dem Kanal austritt. Zudem wurden Geschwindigkeiten in der flüssigen Phase mittels nicht invasiver Verfahren gemessen. Das durchschnittliche Geschwindigkeits-Profil am Kanaleintritt wurde mit Ultraschall-Köpfen bestimmt. Die Ermittlung des Geschwindigkeitsfeldes in einem Schwall erfolgte mit PIV (Particle Image Velocimetry).

No description available.

The Spanish slug (Arion vulgaris) is one of the most problematic invasive species in Europe and a serious pest species in agriculture and gardens, and it can have negative effects on native slug species. In this study, we used passively intergraded transponder (PIT) telemetry to determine the movement behavior of 57 Spanish slugs during autumn in two different habitats: a private garden and a deciduous forest, located in Karlstad municipality, Sweden. The slugs generally moved within relatively small areas. There was a difference between the movements between the two habitats, with slugs moving longer distances per day (2.0 m day‑1) and over larger areas in the forest than in the garden (1.1 m day-1). Local control measures are therefore potentially effective in gardens and in agricultural landscapes, since the Spanish slug there concentrate within patches of habitat. To develop control methods to mitigate the impact of this problematic slug, we need more basic ecological knowledge, and this study provides such knowledge. / Den spanska skogssnigeln (Arion vulgaris) är en av Europas mest problematiska invasiva arter och ett allvarligt skadedjur för jordbruk och trädgårdar. Den kan också ha negativa effekter på inhemska snigelarter. I den här studien använde vi telemetri baserat på passivt integrerade transpondrar (PIT) för att bestämma rörelsemönstret hos 57 spanska skogssniglar under hösten i två olika habitat: en villaträdgård och en lövskog, i Karlstads kommun, Sverige. Sniglarna rörde sig inom små områden. Det var en skillnad mellan rörelserna i de två habitaten, sniglarna förflyttade sig längre distanser per dag (2,0 m dag-1) och över större områden i skogen än i trädgården (1,1 m day-1). Lokala kontrollåtgärder är därför potentiellt effektiva i trädgårdar och jordbrukslandskap, då den spanska skogssnigeln där koncentrerar sig inom fläckar av habitat. För att utveckla kontrollmetoder för att minska påverkan av den här problematiska snigeln, så behöver vi mer grundläggande ekologisk kunskap, och den här studien förser oss med sådan kunskap.

Une identification précise des espèces exotiques est essentielle afin de déterminer la nature et l’ampleur des impacts que ces espèces auront sur leurs nouveaux habitats. Le complexe d’Arion subfuscus s. l., originaire d’Europe, fait partie des limaces les plus abondantes dans le nord-est de l’Amérique du Nord et plusieurs impacts dus à leur présence ont été rapportés. Cependant, l’identité des espèces introduites demeure inconnue dans la plupart des régions. L’objectif de ce projet est donc de déterminer la répartition récente, la diversité taxonomique et l’origine des membres du complexe d’A. subfuscus s. l. au Québec en se basant sur leur identité mitochondriale (16S rDNA). Un total de 526 spécimens provenant de 68 sites à travers le Québec et un site en Nouvelle-Écosse ont été analysés à l’aide de la technique des SSCP et leurs séquences ont été déterminées. Huit haplotypes de deux espèces allopatriques, A fuscus et A. subfuscus s. s. (lignées S1 et S2) ont été détectés. Les résultats confirment que des limaces provenant de régions distinctes d’Europe ont été introduites à de multiples reprises. Une comparaison avec des données historiques de répartition a révélé une expansion fulgurante de la répartition depuis les 50 dernières années. Arion fuscus est la principale espèce envahissante qui a été détectée dans toutes les régions échantillonnées, ce qui contraste avec les études antérieures réalisées ailleurs en Amérique du Nord. Le rôle potentiel des échanges commerciaux internationaux dans l’histoire d’introduction des espèces exotiques est discuté. / Accurate identification of exotic species is required to assess the magnitude and nature of consequences on their new habitats. The Arion subfuscus s. l. species complex comprised slugs of European origins that are amongst the most abundant slug species in northeastern North America and various impacts of their presence are reported. However, the identities of the species introduced remain unknown in most regions. This study aims at determining the current distribution, taxonomic identity and the origins of the members of the A. subfuscus s. l. complex in Quebec (Canada) based on mitochondrial 16S rDNA. A total of 526 specimens from 68 locations throughout Quebec and one site in Nova Scotia were SSCP analysed and their sequences were determined. Eight haplotypes of the allopatric A. fuscus and A. subfuscus s. s. (lineages S1 and S2) were detected. Results confirmed that slugs from distinct European regions were introduced multiple times. Comparison with previous survey revealed an impressive expansion of the distribution during the last 50 years. Arion fuscus is the major invasive species found throughout Quebec, contrasting with previous North American studies. The potential role of international trade in the introduction history of exotic species is discussed.

<div>The current study is aimed at developing a well-posed and objective, i.e., frame invariant, Eulerian one-dimensional (1D) Two-Fluid Model (TFM) to predict flow regime transition from dispersed to clustered bubbly and slug flow for vertical adiabatic two-phase flows. Two-phase flows in general are characterized by local material wave or void fraction wave instabilities and flow regime transitions are one of the important consequences of these instabilities. The physical mechanism of wake entrainment for clustering of dispersed bubbles is proposed, leading to formation of bubble clusters and Taylor bubbles. The focus of the work is on simulation of the local interfacial structures for bubble clusters and Taylor bubbles, using a well-posed, unstable and non-linearly bounded 1D Shallow Water TFM.</div><div><br></div><div>The first part of the current study investigates the dynamic behavior of the well posed 1D mechanistic TFM obtained from the averaging approach of Ishii [1], due to wake entrainment instability. For this, a 1D Shallow Water TFM derived from the 1D mechanistic TFM is used, which retains the same dynamic behavior as that of the latter at short wavelengths and the required wake entrainment force is derived mechanistically. Three stability approaches are followed to study the dynamic behavior of the 1D Shallow Water TFM: characteristics, dispersion analysis, and nonlinear numerical simulations. An in-house code is used for the 1D numerical simulations of the growth of void fraction waves due to wake entrainment. The simulation results are validated with the experimental data of Cheng and Azzopardi [2] and Song et al. [3] To conclude the first part, the 1D results of the two-equation Shallow Water TFM are carried over to the complete four-equation TFM for quasi 1D simulations using the commercial CFD code of ANSYS Fluent.</div><div><br></div>As an alternative to the mechanistic approach, which is based on Newtonian mathematics, a variational approach based on Lagrangian and Hamiltonian mathematics is used in the second part of the thesis. While the mechanistic approach operates in terms of forces acting on the two-phase mixture, the variational approach operates in terms of energies of the two-phase system. To derive the equations of motion using the variational approach, the extended Hamilton principle of least action is applied to the Lagrangian density of the two-phase mixture. One of the appealing features<br>17<br>of this procedure is that the derived equations of motion are objective (Geurst [4]), in particular the added mass terms.<br>Thus, the second part of the current study focuses on deriving an objective, well-posed and unstable 1D TFM as well as developing a constitutive model for the wake entrainment effect using the variational method. Additional momentum transfer terms present in both the liquid phase and gas phase momentum equations, which render the variational TFM objective, are discussed. The variational method is then used to derive the 1D Shallow Water TFM using the fixed flux assumption. The conservative interfacial momentum transfer terms require formulation of the inertial coupling between the phases. Potential flow theory is first used to derive the inertial coupling coefficient for a single bubble and then for a pair of bubbles to consider interaction between the two bubbles. Then, a lumped parameter model is used to derive the inertial coupling coefficient for the wake entrainment effect. A local drag coefficient is obtained for the non-conservative interfacial drag force from the experimental data using kinematic approximation, i.e., force balance between drag and gravity. The linear and non-linear stability analyses are used to address the stability of the 1D variational Shallow Water TFM. The presence of appropriate short-wave physics makes the 1D Shallow Water TFM hyperbolic well-posed and kinematically unstable. Finally, numerical simulations are performed to demonstrate the development of void fraction waves due wake entrainment. The growth of void fraction waves is non-linearly bounded, i.e., Lyapunov stable. The simulation results are compared with the experimental data to validate the propagation properties of void fraction waves for bubble clusters and Taylor bubbles. This work illustrates the short-wave two-phase flow simulation capability of the TFM for the bubbly to slug flow regime transition.

Direct mountain front recharge (MFR), water table recharge at the base of the mountain front, was evaluated on the arid (<250 mm/yr precipitation) Silver Island Mountains by comparing mountain precipitation to groundwater response. Direct MFR contributions were assessed on two catchments, one bedrock (i.e., mountain block) dominated and the other alluvial fan (i.e., mountain front) dominated. Catchment precipitation and shallow groundwater levels at each catchment outlet were measured for a 24 month period beginning October 2005. This time period captured one complete hydrologic cycle (December 2005-February 2007) for which annual and seasonal direct MFR rates were calculated. Annual direct MFR was calculated using a modified version of the water table fluctuation (WTF) method as 0.015-0.016% of precipitation on both catchments, with seasonal variations of 0% in summer up to 0.023% in winter, spring and fall. Seasonal direct MFR contributions are similar on the bedrock and the alluvial fan dominated catchments, with a notable exception during fall 2006 when direct MFR was twice as effective on the bedrock dominated system than on the alluvial fan dominated system (0.022% and 0.011% of precipitation, respectively). Darcy's law calculations show similarly low annual direct MFR contributions (0.013-0.032% of precipitation) as those calculated by the WTF method. Calculated direct MFR is 10% or less than typical calculated combined MFR (near surface recharge and deep underflow from the mountain block) for similar terrains and climates, and is only 3.5% of the combined MFR for the Silver Island Mountains as calculated by the Maxey-Eakin model. However, based on total recharge to the adjacent playa, it is apparent that the Maxey-Eakin model overestimates combined MFR, and the small calculated direct MFR is at least 50% of combined MFR. Despite some uncertainty in the numerical results, several patterns are evident in the data. The data show that direct MFR occurs in response to small rainfall events throughout much of the year, and that snowmelt is not necessary to produce direct MFR. The data also show that direct MFR responds more quickly and flushes through the system faster on the alluvial fan catchment than on the bedrock catchment.

Petróleo Brasileiro S.A. / O presente trabalho aborda o comportamento da planta de processamento primário com alimentação por fluxo em padrão de golfadas. O fluxo no sistema de tubulações é descrito por um modelo de parâmetros concentrados, fornecendo as características principais necessárias para o controle da planta, e a resposta dinâmica desta pode então ser analisada. Usando a estratégia de controle tradicional verifica-se que as oscilações de fluxo são transmitidas para as vazões de saída de líquido e gás, para obter uma vazão de saída mais estável é permitida a flutuação de carga no separador dentro de uma tolerância, isto é possível reduzindo a atuação do controlador e estabelecendo um controle adicional diretamente na válvula de entrada. / The present work addresses the behavior of a primary processing plant subjected to slug flow pattern at its entrance. The flow in a pipeline system is described by a simplified concentrated parameter model, which preserves the main physical features that are important to control the plant. The dynamic response of the plant is then analyzed. Using a standard control strategy for the gas liquid separator, it is seen that the flow oscillations are transmitted to the liquid and gas outlets. In order to obtain a more stable outlet flow, the liquid level in the separator is then allowed to fluctuate within a given range, by reducing the effect of the controller constants, and establishing an additional control directly on the inlet entrance valve.