Clean and safe water is important for the well being of all organisms on earth. Therefore, it is important to reduce harmful emissions from industrial processes that use water in different ways. In vehicle washing processes, water is used in high-pressure processes, as a medium for detergents, and for rinsing of vehicles. The wastewater produced by these functions passes through a water reclamation system. A water reclamation system has two main functions, to produce reusable water to be used in future washing cycles, and to separate contaminants and purify the wastewater so it can be released back into the commercial grid. The reclamation system achieves this by using a combination of different water handling processes, these include: sludge tanks, an oil-water separator, a water reclamation unit, buffer tanks, and a water purification unit. The two components that stand for the more advanced cleaning processes are the water reclamation unit and the water purification unit. In this thesis, in collaboration with the company Westmatic, the water reclamation unit consists of cyclone separators that use centrifugal forces to separate heavy particles and ozone treatment to break up organic substances and combat bad odors. The Purification unit of choice is an electrocoagulation unit that, by a direct current, creates flocculants of impurities that rises to the surface and can be mechanically removed in a water volume inside the unit. This purification process is completely chemical-free thus making the process more environmentally friendly than other purification processes used in other circumstances. This master thesis aimed to develop a dynamic design tool for a modular solution of the different parts in the water reclamation system. This design tool uses specific user input to produce construction information for each instance. As an additional sub-aim, this design tool was linked with a computer-aided design program to produce parametric 3D models with underlying blueprints. This to produce a light solution, that has a short manufacturing time and that are highly customer adjusted. The first course of action was to mathematically define the complete water reclamation system and its components. These sections were described in a flowchart that shows how the different parts interact and operate. From the wash station, wastewater runs trough a course- and fine-sludge tank. From the fine sludge tank, the wastewater is directed in two different directions. Firstly, the water is pumped to the water reclamation unit and to one or multiple buffer tanks to finally be used in the wash station as reclaimed water. Secondly, the water travels to an oil separator, pump chamber, and water purification unit. In the purification unit, 99% of the inlet mass is directed out of the system as purified water. The remaining 1% is directed to a depot that acts like the end stage of the whole system. After all equations were defined and the design was related to the user-defined input flow the design tool was structured. The program of choice to house the design tool is Microsoft Excel. In this Excel document, a user interface with navigation was constructed and the intended user is directed through a series of input pages where input data is defined. This data is used in a normally hidden page where constructional dimensions are calculated. The constructional dimensions are displayed to the user on the second last page. At this stage the Excel document can be connected to a CAD program and 3D models with blueprints can be opened that depend on the output from the Excel file. Additionally, a pipe calculator is provided on the last page of the Excel document where pipe dimensions for different cases can be found. With this solution, glass fiber tanks are molded according to the resulting blueprints that are customer specific. In this way the solution is more adaptive and easier to handle. Additionally, the provided design tool enables an easier and more well-defined methodology when deriving the different needed volume and accompanied constructional dimensions for an arbitrary water reclamation system.

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[pt] Rampas de revezamento (RRs) são zonas altamente deformadas e que representam caminhos preferenciais do fluxo de fluidos nos reservatórios do pré-sal. O trabalho reside no estudo do comportamento do fluxo de fluidos e da poropressão em diferentes geometrias de RRs, para cenários de injeção e produção de um reservatório carbonático. Foram construídos dois modelos 2D de RR: soft-linked e hard-linked, e atribuído a eles propriedades para os materiais matriz, RR e zona de falha e definidas as condições iniciais e de contorno. Para cada modelo foram gerados três submodelos, nos quais se variou a posição dos poços. Definiu-se dois pontos observadores, um para cada modelo, no centro das RRs e foram testados sete cenários. Os resultados mostraram que, de maneira geral, as rampas soft-linked promovem uma maior comunicação no reservatório do que as rampas hard-linked. A influência da geometria da rampa foi significativa nas condições em que a permeabilidade da rampa e da matriz eram mais baixas e a poropressão não apresentou grande variação, ou seja, em reservatórios carbonáticos, cujo fluxo é dominado principalmente por falhas e fraturas. Contudo, à medida que a porosidade e permeabilidade aumentaram, assim como a variação da poropressão, a geometria da rampa passou a ter uma importância secundária comparada à disposição dos poços, ou seja, em reservatórios carbonáticos, cuja matriz é de boa qualidade permo-porosa. As fraturas na RR, a depender da direção em relação ao campo de tensões, tornaram o fluxo tortuoso. O estudo realizado trouxe importantes informações que podem auxiliar na otimização de malhas de drenagem de reservatórios carbonáticos e na recuperação dos hidrocarbonetos. / [en] Relay Ramps (RRs) are highly deformed zones and represent preferential fluid flow paths in pre-salt reservoirs. The purpose of this work is to study the behavior of fluid flow and poropressure in different relay ramp (RR) geometries, for injection and production scenarios of a carbonate reservoir development. Two 2D ramp models were built: soft-linked and hard-linked, assigned properties for the matrix, relay ramp and fault zone (damage zone and fault core) materials and defined initial and boundary conditions. For each model three sub models were generated, in which the position of the wells variated. Two observer points were defined, one for each model, in the center of the RRs and seven scenarios were tested. The results showed that, in general, soft-linked ramps promote greater reservoir communication than hard-linked ramps. The geometry influence of the ramp was significant in the conditions where the ramp and matrix permeability were lower and the poropressure did not vary much, that is, in carbonate reservoirs, whose flow is mainly dominated by faults and fractures. However, as porosity and permeability increased in the ramp and matrix, as well as the variation of poropressure, the geometry of the ramp became of secondary importance compared to the wells layout, that is, in carbonate reservoirs, whose matrix has high porosity and permeability. The fractures in RR, depending on the direction in relation to the stress field, made the flow tortuous. The study brought important information that can help in the optimization of drainage plan in carbonate reservoirs and the recovery of hydrocarbons.

The interaction between a bluff body and the impinging fluid flow, can involve detached boundary layers, massive flow separations, free shear layers, development of recirculation zones and formation of a highly disturbed and complex region downstream of the bluff body, which can be categorized as wake. The present research aims to experimentally investigate such fluid-structure interaction and provide insight into the wake structure of two bluff bodies. To this end, the airwake over the helicopter platform of a Canadian Coast Guard (CCG) polar icebreaker was studied using high-speed particle image velocimetry (PIV). The experiments were conducted on a scaled model of the polar icebreaker situated on a costume-built and computer-controlled turntable, which provided the ability to accurately change the incidence angle of the impinging flow with a given rate of change for incidence angle. Quantitative flow field data were obtained in several vertical and horizontal planes. The obtained velocity field was then used to calculate the time-averaged flow structure and turbulence metrics over the helicopter platform of the vessel. The present work compared the effects of two types of inflow conditions: (i) a uniform flow and (ii) a simulated atmospheric boundary layer (ABL) on the flow structure over the helicopter platform of the ship. Moreover, for the bluff scaled model, the effects of the Reynolds number on the wake structure and the flow patterns were investigated. The incidence angle (α) between the oncoming flow and the orientation of the ship varied between 0° to 330° with the increment of 30°. It was observed that higher maximum values of the turbulence intensity were associated with the simulated ABL. Moreover, it was found that for both inflow conditions, the incidence angle of 300o corresponded to the highest turbulence levels over the helicopter platform. Building on the results obtained for a stationary vessel in the simulated ABL, this work aimed to quantify the effects of the unsteady change in the direction of the impinging wind, simulated by rotating the model at a certain rate, . It was observed that the increase of the rate of change of the inflow direction resulted in an increase of the turbulent intensity over the helicopter platform. However, an exception was observed for the case of α = 60°, where clockwise rotation of the ship model with respect to the inflow exposed the helicopter platform to increased turbulent velocity fluctuations, while counterclockwise rotation diminished the flow unsteadiness over the helicopter platform. Moreover, aiming to identify the origins of the unsteady forces applied on bluff elongated plates with high chord-to thickness ratio (c/t = 23) at zero incidence, direct force measurement as well as PIV were used to identify the effect of transverse perforations on the flow-induced loading on the flow structure in the near-wake of the plates. The experiments were conducted in a water channel, where the plates were located at the center of channel, parallel to the upstream flow direction. Plates with various characteristic diameter of the perforation as well as a reference case without perforations were considered. The spectra of the trailing-edge vortex shedding and flow-induced forces were compared and it was observed that the vortex shedding frequencies were in very good agreement with those of the measured flow-induced forces for all considered perforation patterns. Thus, it was determined that the trailing-edge vortex shedding was the main mechanism of generating the unsteady loading on the plates. The staggered patterns of the perforations created a three-dimensional flow structure at the vicinity of the trailing edge and in the near wake, which was investigated using PIV at several data acquisition planes. It was found that in the cross-sectional planes corresponding to the close proximity of the perforations to the downstream edge, the periodic trailing-edge vortex shedding were suppressed. Furthermore, it was observed that for small perforations, the velocity fluctuations in the near wake were enhanced. However, further increase of the perforation diameter led to suppression of the velocity fluctuations. / Graduate

<p>U mnogim granama tehnike javljaju se problemi<br />merenja protoka fluida. Merne blende, zbog svojih<br />mnogih prednosti predstavljaju najzastupljeniji<br />instrument za merenje protoka fluida kroz cevovode. Sa<br />druge strane njihova upotreba povećava tro&scaron;kove rada<br />industrijskih postrojenja. Jedan od ciljeva ove<br />doktorske disertacije bio je ispitivanje novih oblika<br />mernih blendi u cilju u&scaron;tede energije pri njihovom radu.<br />U ovoj doktorskoj disertaciji predložen je algoritam<br />ispitivanja novih oblika mernih blendi. Takođe je<br />konstruisana i izrađena laboratorijska aparatura za<br />njihovo ispitivanje kao i diferncijalni &quot;U&quot; manometar<br />za merenje malih razlika pritisaka. U okviru ove<br />doktorske disertacije dizajnirana su i ispitana tri nova<br />oblika mernih blendi. U&scaron;teda energije je postignuta<br />dizajnom koji smanjuje otpor merne blende kao<br />elementa cevovoda. Novi oblici mernih blendi, kao i<br />jedna standardnog oblika koja je poslužila kao<br />referentna, ispitani su prema predloženom algoritmu. U<br />prvom koraku merne blende su dizajnirane u<br />programskom paketu Solid Works. Zatim su, prema<br />predloženom algoritmu, ispitane pomoću računarske simulacije u programskom paketu COMSOL Multiphysics. Po dobijanju zadovoljavajućih rezultata računarske simulacije, merne blende su izrađene na 3D &scaron;tampaču, FDM postupkom i ispitane na laboratorijskoj aparaturi. Rezultati laboratorijskih ispitivanja su upoređeni sa rezultatima računarske simulacije. Upoređeni rezultati računarske simulacije i laboratorijskih ispitivanja su pokazali da je računarska simulacija dobro opisivala situaciju. Rezultati laboratorijskog ispitivanja su pokazali znatan efekat u&scaron;tede energije. Takođe je utvrđeno da se pomoću računarske simulacije mogu dobiti podaci na osnovu kojih se može doneti odluka da li novi oblik merne blende treba korigovati ili ima smisla pristupiti laboratorijskom ispitivanju. Algoritam ispitivanja koji je predložen u ovoj doktorskoj disertaciji se pokazao efikasnim.</p><p>&nbsp;</p> / <p>In many domains of technology, there are problems<br />with the measurement of fluid flow. Orifice plates,<br />because of their many advantages, represent the most<br />common instrument for measuring fluid flow through<br />pipelines. On the other hand, their use increases the<br />operating cost of industrial plants. One of the goals of<br />this doctoral dissertation was to test new forms of<br />orifice plates for a reason to save energy during their<br />work. An algorithm for testing new forms of orifice<br />plates is proposed. Also, the laboratory equipment for<br />testing them was designed and made, as well as a<br />differential &quot;U&quot; manometer for measuring small<br />pressure differences. As part of this doctoral<br />dissertation are designed and tested three new forms of<br />orifice plates. Energy-saving was achieved by a design<br />that reduces the resistance of the orifice plate as an<br />element of the pipeline. New forms of orifice plates, as well as a standard shape, which served as a reference, were tested according to the present algorithm. In the first step, orifice plates are designed in the Solid Works software package. Then, according to the proposed algorithm, they were tested using computer simulation in COMSOL Multiphysics software package. After achieving satisfactory results of computer simulation, orifice plates are made on a 3D printer, using the FDM process and tested in the laboratory apparatus. The results of laboratory tests were compared with the results of computer simulations. Compared results of computer simulation and laboratory testing showed that computer simulation described the situation well. The results of the laboratory test showed a significant energy-saving effect. It was also found that computer simulation can obtain data that can decide whether a new form of orifice plate must be corrected or it makes sense to access laboratory testing. The algorithm proposed in this doctoral dissertation has proven effective.</p>

<p>Multiphase flows, such as liquid/gas and solid/gas, dominate many different areas of life, including the medical, agricultural, propulsion, and chemical industries. Gaining insight into the dynamic processes that drive these multiphase flows can therefore have far-reaching impact in many sectors of scientific research. Of key interest is the non-invasive tracking of important state properties such as the mass and temperature distributions in high optical depth multiphase flows. To accomplish this, X-ray diagnostic approaches are utilized due to their ability to probe complex phenomena without being hampered by multiple scattering that arise from complex interactions at the flow surface boundaries.</p> <p>This work accomplishes the measurement of mass distribution through time-resolved tomographic reconstructions of the liquid mass distributions in fuel sprays within liquid/gas flows. The developed diagnostic tool shown here uses a novel multiple line of sight tube source tomography setup to obtain simultaneous time-resolved two-dimensional radiographs of different spray geometries at various perspectives. Through tomographic reconstruction, these radiographs are converted into volumetric reconstructions to give a true sense of mass distribution—where exactly is the liquid mass located in the <em>x</em>, <em>y</em>, <em>z</em> spatial extents at a specific moment in time <em>t</em>? This technique is first showcased in a simple spray as a feasibility test and later applied to a more complex spray geometry and compared against other state-of- the-art diagnostics for a full quantitative understanding of the developed technique. Outside of tomography, improvements in decreasing the uncertainties in line of sight averaged mass distribution measurements in radiography imaging experiments are also showcased through source characterization efforts both for tube source and synchrotron source experiments.</p> <p>Efforts in ascertaining the temperature distributions in liquid/gas flows is done through an application of wide angle X-ray scattering, a technique that is commonly used in the materials, chemistry, and biology sciences but has yet to be widely used in the propul- sion community. These newly developed X-ray scattering measurements are accomplished through the use of a focused monochromatic beam available at the Advanced Photon Source synchrotron facility, and is applied first in calibration jets and later towards more complex dynamic sprays and multi-species liquid solutions.</p>

A three-dimensional computational tool was developed that simulates the heat and mass transfer interaction in a soil-root-stem system (SRSS) for a tree in a seasonally varying deciduous forest. The development of the SRSS model involved the modification and coupling of existing heat and mass transport tools to reproduce the three-dimensional diurnal internal and external temperatures, internal fluid distribution, and heat flow in the soil, roots, and stems. The model also required the development of a parallel Monte-Carlo algorithm to simulate the solar and environmental radiation regime consisting of sky and forest radiative effects surrounding the tree. The SRSS was tested, component-wise verified, and quantitatively compared with published observations. The SRSS was applied to simulate a tree in a dense temperate hardwood forest that included the calculations of surface heat flux and comparisons between cases with fluid flow transport and periods of zero flow. Results from the winter simulations indicate that the primary influence of temperature in the trunk is solar radiation and radiative energy from the soil and surrounding trees. Results from the summer simulation differed with previous results, indicating that sap flow in the trunk altered the internal temperature change with secondary effects attributed to the radiative energy from the soil and surrounding trees. Summer simulation results also showed that with sap flow, as the soil around the roots become unsaturated, the flow path for the roots will be changed to areas where the soil is still saturated with a corresponding increase in fluid velocity.

<p>Firstly, select a nozzle and get all its parameters like spray angle, mass flow rate, dipersion angle and nozzle diameter. Create a domain in which 2 nozzles can fit, as shown in thesis. Divide the domain in 2 zones and perform fine mesh on the top surface of solid surface where spray will heat. Write a function for slab temperature variation and give it as the solid part input. Use DPM model, to create injectors inside the domain and solve.</p>

<p>  </p> <p>Acoustic streaming is a phenomenon which occurs when acoustic excitations interact with a fluid (stationary or non-stationary). Exploitation of this phenomenon has the potential to open doors to new methods of flow control through the enhancement or diminishment of the present flow instabilities. A particular use of acoustic streaming shown by previous numerical studies is the enhancement of heat transfer in violation of the Reynold’s Analogy within a small range of Mach numbers and frequencies of periodic excitation. The focus of this thesis is to experimentally assess the usage of a Rossiter cavity in generating periodic acoustic excitations and its effects on the shear stress and heat transfer. </p> <p>In the present research, two large models are tested using a blow-down facility. The models are made of aluminum and Teflon and were developed to ensure optical access for infrared thermography. The geometries are tested at Mach number ranging from 0.373 to 0. 866. The target Mach number-frequency pair where significant heat transfer enhancement is a free stream Mach number at the cavity, Mc, of 0.75 and the frequency, fc, of 7.5 kHz. The cavity is tuned using the Rossiter equation with Rossiter constants k = 0.66 and y = 0.25. The heat transfer and skin friction enhancement are measured immediately upstream and downstream of the cavity and compared to the previous numerical studies.</p> <p>When testing the Teflon model with an ambient back pressure and 11 lb/s mass flow, a frequency of 7.8 kHz was generated by the cavity. For the aluminum model tested at a high vacuum and 3 lb/s mass flow, frequencies near 7, 10, and 20 kHz were generated by the cavity with 10 and 20 kHz appearing most often. High speed schlieren imaging was used to confirm the flow structures being generated in the flow. There was good agreement with the Rossiter modes at lower Mach numbers and moderate agreement at transonic Mach numbers. A correlation is presented which defines a band of Mach number-Reynolds number pairs which present with a discontinuous frequency behavior during operation of the wind tunnel. Measurable effects on both skin friction and heat transfer between tests with comparable operating conditions to a reference were observed and are presented.</p>

<p>Droplet dispersions with adsorbed exotic surface active species (proteins, fatty alcohol, fatty acids, solid particulates, lipids, or polymers) find an immense number of applications in the field of engineering and bioscience. Interfacial rheology plays an essential role in the dynamics of many of these systems, yet little is understood about how these effects alter droplet dynamics. Most surfactants studied historically have been simple enough that the droplet dynamics can be described by Marangoni effects (surfactant concentration gradients), surface dilution, and adsorption/desorption kinetics without including the intrinsic surface rheology. One of the challenges in examining droplet systems with complex interfaces is that the intrinsic rheological effects are strongly coupled with surfactant transport effects (surface convection, diffusion, dilution and adsorption/desorption). The surface rheology can impact the ability of surfactant to transport along the surface, while surfactant transport can alter the surface rheology by changing the surface concentration. In this work, we develop axisymmetric boundary-integral simulations that allow us to quantitatively explore the combined effect of intrinsic surface rheology and surfactant transport on droplet dynamics in the Stokes flow limit. We assume that the droplet interface is predominantly viscous and that the Boussinesq Scriven constitutive relationship describes the properties of the viscous membrane. The key questions that we address in this work are:</p> <p><br></p> <ul> <li>How do viscous membranes impact droplet deformation, breakup and relaxation?      </li> </ul> <p>     When a droplet is placed under external flow, it can either attain a stable shape under flow or stretch indefinitely above a critical flow rate and break apart. In this topic, we first discuss the breakup conditions for a droplet suspended in an unbounded immiscible fluid under a general linear flow field using perturbation theories for surface viscosity in the limit of small droplet deformation. We neglect the inhomogeneity in surfactant concentration and surface tension for this part. We find that the surface shear/dilational viscosity increases/decreases the critical capillary number for droplet breakup compared to a clean droplet at the same capillary number and droplet viscosity ratio value. In the second part of this topic, we solve the problem using boundary integral simulations for the case of axisymmetric extensional flow. Numerically solving this problem allows us to examine the effect of Marangoni stresses, pressure thickening/thinning surface viscosities, and stronger flows. We compare the droplet breakup results from our simulations to results from second-order perturbation theories. We present the physical mechanism behind our observations using traction arguments from interfacial viscosities. We conclude this topic by examining the combined role of surface viscosity and surfactant transport on the relaxation of an initially extended droplet in a quiescent external fluid.</p> <p><br></p> <ul> <li>How do viscous membranes alter droplet sedimentation?</li> </ul> <p>      When an initially deformed droplet sediment under gravity, it can either revert to a spherical shape or undergo instability where the droplet develops a long tail or cavity at its rear end. Here, we use numerical simulations to discuss how interfacial viscosity alters the breakup criterion and the formation of threads/cavities under gravity. We examine the combined influence of intrinsic surface viscosity and surfactant transport on droplet stability by assuming a linear dependence of surface tension on surfactant concentration and an exponential dependence of interfacial viscosities on surface pressure. We find that surface shear viscosity inhibits the tail/cavity growth at the droplet’s rear end and increases the critical capillary number compared to a clean droplet. In contrast, surface dilational viscosity promotes tail/cavity growth and lowers the critical capillary number compared to a clean droplet.</p> <p><br></p> <ul> <li>How do viscous membranes affect droplet coalescence?</li> </ul> <p>      When two droplets approach under external flow, a thin film is formed between the two droplets. Here, we develop numerical simulations to model the full coalescence process from the collision of two droplets under uniaxial compressional flow to the point where the film approaches rupture. We investigate the role of interfacial viscosity on the film profiles and drainage time. We observe that both surface shear and dilational viscosity significantly delay the film drainage time relative to a clean droplet. Interestingly, we find that the film drainage behaviour of a droplet with surface viscosity is not altered by the relative ratio of shear to dilational viscosity but rather depends on the sum of shear and dilational Boussinesq numbers. This is in contrast to the effect of surface viscosity observed in the previous processes (droplet breakup and sedimentation), where surface shear viscosity increases the critical capillary number compared to a clean droplet, while surface dilatational viscosity has the opposite effect.</p>