Abstract Not Provided / Thesis / Master of Engineering (MEngr)

CEJN is a leading transnational company with long history and professional background providing high-tech quick connect products in global market. The headquarters of the com-pany in Skövde, Sweden, is the birthplace and core location of the entire corporation. In the headquarters, the engineer tests their products at their flow test laboratory. In the laboratory, there are flow test stations for all product ranges. Within them, the most basic are flow test benches for air, water and hydraulic oil products. The flow test benches are aim to test the products under International/Swedish standard conditions to determine the performance. This project is aimed in upgrading the test benches by engineering both hardware and soft-ware, to achieve higher level of automation of the data logging system used in the lab. All three test benches were designed and installed following requirements in corresponding in-ternational standards. The principles of testing are similar, but they are not developed from the same era, and the automation level of each test bench differs. As a result, the need of up-grading in the benches is different. In the laboratory, the recorded test results are reorganized and processed by a report genera-tor developed on Microsoft Excel. The Excel report generator is used for organize test results, calibrate the deviation of the instruments, calculate the flow coefficient of the product, gener-ate performance diagrams of the products, generate test reports for different purpose of use, and save the test data and results on the server of the company. Above all, an upgrade of the data logging system for the three flow test benches was needed. Depending on the conditions of each test bench, the project is implemented and designed the following three parts: • A hardware upgrading (flow rate computer) for the air flow test benchA new signal indicating device for replacing the old flow rate computer is purchased from Italy by the company. The new instrument contains filter function to stabilize the flow rate value. • A software upgrading (Excel report generator) for all the test benchesVisual Basic for Applications (VBA) programming language is used for developing functions such as data communication, signal decoding and user interface developing in Excel. • Develop of an automated data visualizing system for the air flow test benchData communication from the new instrument to a PC through serial port and Mod-bus RTU interface is established. The data visualizing function is compiled in the Ex-cel report generator for the air flow test, realized by VBA programming.

One of the current testing method (the Dry Flow test) to qualify resin for use in production in the rotomolding process has been shown to have many flaws in both equipment and procedure. Research was done here to investigate a possible alternative that could eliminate some of these testing deficiencies. By reducing equipment and operator errors, the testing of materials becomes more valuable of an exercise. The Angular Flow test developed in this research can increase repeatability. By coming to understand the rotational molding process better, an evaluation that can give more valid information was devised.

A new centrifugal pump has been devised to handle two-phase flow. However, it requires full scale testing to allow further development. Testing is required to verify performance and to gain information needed to apply this design in the field. Further, testing will allow mathematical models to be validated which will allow increased understanding of the pump's behavior. To perform this testing, a new facility was designed and constructed. This facility consists of a closed flow loop. The pump is supplied by separate air and water inlet flows that mix just before entering the pump. These flows can be controlled to give a desired gas volume fraction and overall flow rate. The pump outlet flows into a tank which separates the fluids allowing them to re-circulate. Operating inlet pressures of up to three hundred PSIG will be used with a flow rate of twelve hundred gallons per minute. A two-hundred fifty horsepower electric motor is used to power the pump. The loop is equipped with instrumentation to measure temperature, pressure, flow rate, pump speed, pump shaft horsepower, shaft torque, and shaft axial load. The pump itself has a clear inlet section and a clear section allowing visualization of the second stage volute interior as well as numerous pressure taps along the second stage volute. This instrumentation is sufficient to completely characterize the pump. Design and construction details are provided as well as a history of the initial operating experiences and data collected. A discussion of lessons learned is given in the conclusions. Future projects intended to use this facility are also given. Finally, detailed design drawings are supplied as well as operating instructions and checklists.

The effective and efficient remediation of contaminated groundwater sites requires site specific information regarding the physical, chemical and biological properties of the aquifer. Building on the dipole flow test (DFT) and the dipole flow and tracer test (DFTT), the dipole flow and reactive tracer test (DFRTT) has been proposed as an alternative to current aquifer parameter estimation methods. A steady-state dipole flow field is created by circulating groundwater between chambers isolated by the dipole tool. A tracer is released into the injection chamber and the breakthrough curve at the extraction chamber is interpreted with the DFRTT specific model. The overall goal of this thesis was to demonstrate the ability of a prototype dipole system to produce tracer BTCs in conventional wells installed in an unconfined sandy aquifer. The Waterloo dipole probe was constructed and field tested at CFB Borden. DFTs conducted along the length of the screen of non-filter packed monitoring wells provided similar estimates of radial hydraulic conductivity (Kr) to slug tests and literature values. The geometric mean Kr estimated in the filter packed wells was approximately an order of magnitude greater than the mean Kr estimate for the non-filter packed wells due to short-circuiting through the filter pack. A total of 46 DFTTs were completed in the monitoring wells at CFB Borden to investigate the properties of the BTCs. The shape of the BTC for a conservative tracer is affected by test set up parameters, well construction, and aquifer formation properties. The BTCs from the DFTTs completed in the non-filter pack monitoring wells were categorized into four “type curves” based on the BTC properties. The differences between the type curves were largely defined by the ratio of K between the skin zone and the aquifer (Ks/Kr). Now that a series of DFTT BTCs have been generated, the DFRTT model will be used to estimate the aquifer parameters. To continue the work outlined in this thesis, DFRTTs are planned for well-documented contaminated sites.

The effective and efficient remediation of contaminated groundwater sites requires site specific information regarding the physical, chemical and biological properties of the aquifer. Building on the dipole flow test (DFT) and the dipole flow and tracer test (DFTT), the dipole flow and reactive tracer test (DFRTT) has been proposed as an alternative to current aquifer parameter estimation methods. A steady-state dipole flow field is created by circulating groundwater between chambers isolated by the dipole tool. A tracer is released into the injection chamber and the breakthrough curve at the extraction chamber is interpreted with the DFRTT specific model. The overall goal of this thesis was to demonstrate the ability of a prototype dipole system to produce tracer BTCs in conventional wells installed in an unconfined sandy aquifer. The Waterloo dipole probe was constructed and field tested at CFB Borden. DFTs conducted along the length of the screen of non-filter packed monitoring wells provided similar estimates of radial hydraulic conductivity (Kr) to slug tests and literature values. The geometric mean Kr estimated in the filter packed wells was approximately an order of magnitude greater than the mean Kr estimate for the non-filter packed wells due to short-circuiting through the filter pack. A total of 46 DFTTs were completed in the monitoring wells at CFB Borden to investigate the properties of the BTCs. The shape of the BTC for a conservative tracer is affected by test set up parameters, well construction, and aquifer formation properties. The BTCs from the DFTTs completed in the non-filter pack monitoring wells were categorized into four “type curves” based on the BTC properties. The differences between the type curves were largely defined by the ratio of K between the skin zone and the aquifer (Ks/Kr). Now that a series of DFTT BTCs have been generated, the DFRTT model will be used to estimate the aquifer parameters. To continue the work outlined in this thesis, DFRTTs are planned for well-documented contaminated sites.

<p>The effects of different shearing processes and sample sizes on the fluid flow anisotropy and its impact on particle transport process in rough rock fractures are significant factors that need to be considered in the performance and safety assessments of underground nuclear waste repositories. The subjects, however, have not been adequately investigated previously in either laboratory experiments or numerical modeling. This thesis addresses these problems using numerical modeling approaches.</p><p>The modeling consists of two parts: 1) fluid flow simulations considering more complex but realistic flow boundary conditions during shear processes that cannot be realized readily in laboratory experiments, using digitalized fracture surfaces scanned in the laboratory, so that anisotropic fluid flow induced by shearing with channeling phenomenon can be directly simulated and quantified; 2) particle tracking simulations to demonstrate the impacts of such channeling effects on characteristic properties of particle transport. The numerical method chosen for the simulations is the Finite Element Method (FEM). Scale effects were considered in the simulations by using fracture surface samples of different sizes.</p><p>The distributions of fracture aperture during shear were obtained by numerically generating relative translational and rotary movements between two digitalized surfaces of a rock fracture replica without considering normal loading. From the evolutions of the aperture distributions during the shearing processes, the evolutions of the transmissivity fields were determined by assuming the validity of the cubic law locally. A geostatistical approach was used to quantify the scale effects of the aperture and transmissivity fields. The fluid flow was simulated using different flow boundary conditions, corresponding to translational and rotary shear processes. Corresponding to translational shear (with a 1 mm shear displacement interval up to a maximum shear displacement of 20 mm), three different flow patterns, i.e., unidirectional (flow parallel with and perpendicular to the shear direction), bi-directional and radial, were taken into account. Corresponding to rotary shear (with a 0.5o shear angle interval up to 90o), only the radial flow pattern was considered. The particle transport was simulated using the Particle Tracking Method, with the particles motion following the fluid velocity fields during shear, as calculated by FEM. For the unidirectional particle transport, the breakthrough curves were analyzed by fitting to an analytical solution of 1-D advection-dispersion equation. The dispersivity, Péclet number and tracer velocity, as well as their evolutions during shear, were determined numerically.</p><p>The results show that the fracture aperture increases anisotropically during translational shear, with a more pronounced increase in the direction perpendicular to the shear displacement, causing significant fluid flow channelling. A more significant increase of flow rate and decrease in travel time of the particles in the direction perpendicular to the shear direction is predicted. The particle travel time and characteristics are, correspondingly, much different when such effects caused by shear are included. This finding may have an important impact on the interpretation of the results of coupled hydro-mechanical and tracer experiments for measurements of hydraulic properties of rock fractures, because hydraulic properties are usually calculated from flow test results along the shear directions, with the effects of the significant anisotropic flow perpendicular to the shear direction ignored. The results also show that safety assessment of a nuclear repository, without considering the effects of stress/deformation of rocks on fluid flow and transport processes, may have significant risk potential. The results obtained from numerical simulations show that fluid flow through a single rough fracture changes with increasing sample size, indicating that representativehydro-mechanical properties of the fractures in the field can only be accurately determined using samples of representative sizes beyond their stationarity thresholds.</p>

The effects of different shearing processes and sample sizes on the fluid flow anisotropy and its impact on particle transport process in rough rock fractures are significant factors that need to be considered in the performance and safety assessments of underground nuclear waste repositories. The subjects, however, have not been adequately investigated previously in either laboratory experiments or numerical modeling. This thesis addresses these problems using numerical modeling approaches. The modeling consists of two parts: 1) fluid flow simulations considering more complex but realistic flow boundary conditions during shear processes that cannot be realized readily in laboratory experiments, using digitalized fracture surfaces scanned in the laboratory, so that anisotropic fluid flow induced by shearing with channeling phenomenon can be directly simulated and quantified; 2) particle tracking simulations to demonstrate the impacts of such channeling effects on characteristic properties of particle transport. The numerical method chosen for the simulations is the Finite Element Method (FEM). Scale effects were considered in the simulations by using fracture surface samples of different sizes. The distributions of fracture aperture during shear were obtained by numerically generating relative translational and rotary movements between two digitalized surfaces of a rock fracture replica without considering normal loading. From the evolutions of the aperture distributions during the shearing processes, the evolutions of the transmissivity fields were determined by assuming the validity of the cubic law locally. A geostatistical approach was used to quantify the scale effects of the aperture and transmissivity fields. The fluid flow was simulated using different flow boundary conditions, corresponding to translational and rotary shear processes. Corresponding to translational shear (with a 1 mm shear displacement interval up to a maximum shear displacement of 20 mm), three different flow patterns, i.e., unidirectional (flow parallel with and perpendicular to the shear direction), bi-directional and radial, were taken into account. Corresponding to rotary shear (with a 0.5o shear angle interval up to 90o), only the radial flow pattern was considered. The particle transport was simulated using the Particle Tracking Method, with the particles motion following the fluid velocity fields during shear, as calculated by FEM. For the unidirectional particle transport, the breakthrough curves were analyzed by fitting to an analytical solution of 1-D advection-dispersion equation. The dispersivity, Péclet number and tracer velocity, as well as their evolutions during shear, were determined numerically. The results show that the fracture aperture increases anisotropically during translational shear, with a more pronounced increase in the direction perpendicular to the shear displacement, causing significant fluid flow channelling. A more significant increase of flow rate and decrease in travel time of the particles in the direction perpendicular to the shear direction is predicted. The particle travel time and characteristics are, correspondingly, much different when such effects caused by shear are included. This finding may have an important impact on the interpretation of the results of coupled hydro-mechanical and tracer experiments for measurements of hydraulic properties of rock fractures, because hydraulic properties are usually calculated from flow test results along the shear directions, with the effects of the significant anisotropic flow perpendicular to the shear direction ignored. The results also show that safety assessment of a nuclear repository, without considering the effects of stress/deformation of rocks on fluid flow and transport processes, may have significant risk potential. The results obtained from numerical simulations show that fluid flow through a single rough fracture changes with increasing sample size, indicating that representativehydro-mechanical properties of the fractures in the field can only be accurately determined using samples of representative sizes beyond their stationarity thresholds. / QC 20101207

Inlet headers in the primary heat transport system(PHTS) of CANDU type reactors, are used to collect the coolant coming from the steam generators and distribute them into the reactor core via several feeders. During a postulated loss of coolant accident (LOCA), depressurization and vapor supplement into the core may occur, which results a deterioration in the heat transfer from fuel to the coolant. When a depressurization occurs, &ldquo / Emergency Coolant Injection(ECI)&rdquo / system in the PHTS in CANDU reactors, is automatically become active and supply coolant is fed into the reactor core via the inlet header and feeders. . This study is focused on the experimental and computational investigation of the ECI effect during a LOCA in a CANDU inlet header. The experiments were carried out in METU Two-Phase Flow Test Facility which consists of a scaled CANDU inlet header having 5 connected feeders. The same tests were simulated with a one dimensional two-fluid computer code, CATHENA, developed by Atomic Energy of Canada Limited(AECL). The average void fraction and the two phase mass flowrate data measured in the experiments are compared with the results obtained from CATHENA simulation. Although a few mismatched points exist, the results coming from two different studies are mostly matching reasonably. Lack of three-dimensional modeling for headers in CATHENA and experimental errors are thought to be the reasons for these dismatches.

The characteristics of fine aggregates, such as shape, angularity, and surface texture, have been shown to influence the performance of concrete and asphalt mixtures and to play an important role in obtaining valuable properties of early age concrete such as workability, and compatibility. However, the measurement of fine aggregate characteristics is not easy. In the present study, 26 fine aggregates, covering a wide spectrum of mineralogy, were examined using direct and indirect test methods in order to evaluate the shape, angularity, and surface texture, as well as to analyze the gradation. The direct test methods, such as AIMS and Camsizer, which provide a digital image of the aggregates proved to be the best. However, the cost of such systems can limit the use of digital imagining systems in practice. The indirect test methods which provide an estimate of aggregate surface characteristics, such as uncompacted void test, mortar flow test, compressive strength test, and flakiness test gave variable results. The uncompacted void test (Method A) was shown to be the most accurate indirect test method. The Camsizer and the sieve analysis test produced identical gradation analysis results when an adequate sample was used. General correlations were developed between the direct and indirect test methods. The non-approved fine aggregates on the TxDOT’s list were analyzed and compared to those of the approved fine aggregates to see whether they could be successfully used. It was found that both LS-5 and LS-8 had good results—even better than the results of some of the approved fine aggregates. Thus, they could be successfully used. / text