The majority of commercially available ultrasonic transducers used to excite and measure wave propagation in structures can be coupled only to a free surface. While convenient, this method is likely to excite multiple structural modes, making data interpretation difficult. Furthermore, the many modes excited make predicting the structure’s response a computationally intensive task. Here the dynamic radial displacement induced by a transient radial point load is calculated at more than 230,000 points on the outer surface of a virgin steel pipe to simulate a typical experiment. The radial component of the displacement field is calculated by convolving the Green’s functions of the pipe with the transient load. These functions are calculated on personal computers (in a distributed arrangement) by employing modal summation. The mode shapes are obtained from a Semi-Analytical Finite Element formulation used in conjunction with a separation of variables. The results are presented in a four dimensional animation, providing easier interpretations and insight into how to best select observation points for the detection of defects. The accuracy of the calculated displacements is verified experimentally. Agreement is good when magnitude and phase corrections are incorporated from the frequency response curves of the transducers used.

Foam is one of the most frequently used multiphase fluids in underbalanced drilling operations because of its high carrying capacity of cuttings, compressibility property, formation fluid influx handling, etc. Foam rheology has been studied for many years. Researchers tried to explain foam behaviour by using conventional methods, i.e., determining rheological parameters of pre-defined rheological models like Power law, Bingham Plastic etc., as a function of gas ratio. However, it is known that bubble size and texture of the foam is also effective on foam behaviour. When foam is generated by using different foaming agents, even if the gas ratio is constant, different rheological parameters are observed. Therefore a more general foam characterization method that uses the bubble size and texture of foam is required. Improvements on image analysis, and computer technology allow monitoring the bubble size and texture of foam bubbles. A more comprehensive model of foam rheology definition in which the bubble size, and texture effects of the foam body is developed. Three different analysis methodologies are introduced / i) Generalized volume equalized approach, ii) Generalized volume equalized approach and image processing data, and iii) Image processing data only. The necessary information including the rheological information and image data is acquired from the experimental set-up developed for this study. It has been observed that, the pressure losses could be predicted as a function of bubble size, circularity and general rheological parameters, in &amp / #61617 / 20 % certainty limit. It is also observed that using only the image information is possible to characterize the foam in an accurate and fast manner.

ABSTRACT DESIGN OF A CONNECTED PIPE TEST FACILITY FOR RAMJET APPLICATIONS SARISIN, Mustafa Nevzat M.S., Department of Mechanical Engineering Supervisor: Asst. Prof. Dr. Abdullah ULAS Co-Supervisor: Prof. Dr. Kahraman ALBAYRAK April 2005, 164 pages Development of the combustor of a ramjet can be achieved by connected pipe testing. Connected pipe testing is selected for combustor testing because pressure, temperature, Mach number, air mass flow rate can be simulated by this type of testing. Real time trajectory conditions and transition from rocket motor (booster) to ramjet operation can also be tested. The biggest advantage of connected pipe testing is the low operation cost and simplicity. Air mass flow rate requirement is less than the others which requires less air storage space and some components like supersonic nozzle and ejector system is not necessary. In this thesis, design of a connected pipe test facility is implemented. Three main systems are analyzed / air storage system, air heater system and test stand. Design of air storage system includes the design of pressure vessel and pressure &amp / flow regulation system. Pressure and flow regulation system is needed to obtain the actual flow properties that the combustor is exposed to during missile flight. Alternatives for pressure and air mass flow rate regulation are considered in this study. Air storage system designed in this thesis is 27.8 m3 at 50 bar which allows a test duration of 200 seconds at an average mass flow rate of 3 kg/s. Air heater system is utilized to heat the air to simulate the aerodynamic heating of the inlet. Several different combustion chamber configurations with different flame holding mechanisms are studied. The most efficient configuration is selected for this study. Combustion analysis of the air heater is performed by FLUENT CFD Code. Combustion process and air heater designs are validated using experimental data. Designed air heater system is capable of supplying air at a temperature range of 400-1000 K and mass flow rate range of 1.5-8 kg/s at Mach numbers between 0.1-0.5 and pressure between 2-8 bar. Finally the design of the test stand and ramjet combustor analysis are completed. 3D CAD models of the test stand are generated. Ramjet combustor that will be tested in the test setup is modeled and combustion analysis is performed by FLUENT CFD Code. The ramjet engine cruise altitude is 16 km and cruise Mach number is 3.5. Key-words: Air Breathing Engines, Ramjet, Connected Pipe, Direct Connect, Vitiator.

Since the discovery of the drag reduction effects of even small amount of macromolecules in solutions in turbulent pipe flows, there have been many experimental and theoretical studies in order to understand mechanisms behind this phenomenon. Theories have been proposed based on the observations on the change in the characteristics of the turbulent flow near the pipe wall where friction of the momentum transfer between the flow and the conduit takes place. In this study drag reduction in fully developed turbulent pipe flow with four concentrations (200 to 500 wppm) of low molecular weight Sodium Carboxymethylcellulose (CMC) in aqueous solutions was investigated experimentally. Drag reduction was determined by pressure drop measurements. In order to observe the impact of the presence of CMC on the flow, Ultrasound Doppler Velocimetry (UDV) was employed to monitor the instantaneous velocity distributions. UDV is a non-invasive technique allowing one to obtain quick velocity profiles. Experimental measurements were used to calculate Fanning friction factor and radial distributions of the axial time-averaged velocity, velocity fluctuation (turbulent intensity) and eddy viscosity. The drag reduction level was determined through the Fanning friction factor versus Reynolds number data. Velocity data could be obtained as close as 3 mm to the wall by UDV. Two impacts of increasing CMC concentration on the flow field, hence pressure drop, were observed. The first effect was the decrease of the mean velocity gradient especially near the wall with increasing polymer amount which in turn gave rise to lower friction factor or pressure drop. In addition smaller eddy viscosities were obtained in the flow. The second impact of the polymer addition was on the velocity fluctuation or turbulent intensity variation along the radial distribution. An increasing trend in turbulence intensity in the turbulent core with polymer addition was observed. This was in agreement with the earlier studies in which similar turbulence behavior was observed in addition to the suppression of the turbulent intensities near the wall

Single leaf in pocket on back end paper. / Bibliography: p. 475-488. / xxviii, 488 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study aims to develop a robust set of tools to model the performance of a range of composite coil configurations, to develop an operational model to predict the steady state performance of single and multizone air conditioning systems and to use the computational model as an exploratory tool to examine the performance of a series of candidate design solutions. / Thesis (Ph.D.)--University of Adelaide, Dept. of Mechanical Engineering, 1996?

Orientador: Paulo César Razuk / Banca: Augusto Ronchi Junior / Banca: Waldemar Gastoni Venturini Filho / Resumo: A fermentação alcólica, processo central da indústria cervejeira é um processo que libera uma grande quantidade de calor. Sendo assim, os recipientes de fermentação devem estar equipados com instalações de refrigeração para o correto controle da temperatura. A presente pesquisa tem como objetivo a análise da troca de calor de fermentadores cilindrocônicos dotados de sistema de refrigeração direta através de serpentina meia-cana. Para a consecução desse objetivo foi necessária a elaboração de um roteiro de cálculo seguro baseado em equações e experiências encontradas em renomadas literaturas. A análise dos resultados encontrados foi realizada a partir dos valores obtidos através do programa de cálculo atualmente utilizado em uma das maiores empresas fornecedoras deste tipo de equipamento para o mercado cervejeiro, a Dedini Indústrias de Base. Constatou-se que os valores obtidos pelo roteiro apresentado na presente dissertação foram maiores do que os calculados no programa, concluindo-se que as diferenças e dificuldades de resfriamento encontradas em equipamentos semelhantes fornecidos a clientes distintos podem ter origem na quantidade de refrigerante. As estimativas para o coeficiente global de transferência de calor independem do roteiro de cálculo seguido, pois há uma variação máxima de 3,5 % nos resultados para o cálculo deste. O mesmo é verificado para as vazões mássicas de amônia requerida, onde esta variação é ainda menor (cerca de 3,0%) / Abstract: Alcoholic fermentation, brewery industry's central process that liberates a great amount of heat. Therefore, the fermentation containers should be equipped with cooling installations for correct temperature control. The present research aims to analyze the heat exchange in cylindroconical fermenters endowed with a halp-pipe coil direct cooling system. To achieve this objective, the elaboration of a sate calculation route based on equations and experiences found in renowned references was necessary. The validation of the results was accomplished from the values obtained through the calculation program now used in one the largest supplying companies of this kind of equipment for the brewer market, Dedini indústrias de Base. It was verified that the flow of ammonia for the cooling system obtained by the itinerary introduced in the present article was larger than the one calculated in the program, and it can be concluded that the differences and cooling difficulties found in similar equipments supplied to different customers can have origin in the amount of ammonia used in the cooling system. The values for the overal heat transfer coefficient do not depend on the calculation itinerary followed, because there is a maximum variation of 3.5% in the results for the calculation of the coeffiecient. The same is verified for the mass flows of requested ammonia, where this variation is still smaller (about 3.0%) / Mestre

O presente trabalho tem como objetivo avaliar as tensões atuantes no conjunto conector e duto flexível de camadas não aderentes durante ensaios com carregamentos axiais de tração e fadiga. Estes ensaios são utilizados para a qualificação de dutos flexíveis. Foram desenvolvidos e patenteados alguns modelos de conectores contemplando apenas a parte estrutural. Ensaios preliminares de tração e fadiga, com dois conectores diferentes e um segmento de riser de dimensões reduzidas, foram realizados visando a seleção do modelo de melhor desempenho em um pórtico. O conector de melhor desempenho foi então ensaiado em uma bancada com dimensões que atendessem ao documento da Petrobras a I-ET 3500.00.6500-291-PAZ-001 - Non standartized Prototype qualification tests of flexible pipes (2007). Tanto os ensaios do pórtico como o de bancada, foram monitorados com strain gages colados nos tendões da armadura externa de tração próximos aos conectores. O foco deste trabalho está nas armaduras de tração na interface com a resina do conector. Questões quanto ao desempenho da mesma em fadiga são de grande importância prática. Complementando a parte experimental, foram construídos modelos sólidos tridimensionais, baseados no Método dos Elementos Finitos para análise das tensões. A comparação dos resultados das diferentes metodologias validou o modelo numérico possibilitando melhor entendimento das variações de tensões nas armaduras de tração na interface com os conectores. Isso possibilitou responder a importantes questões quanto ao desempenho em fadiga bem como possíveis melhorias no projeto de conectores para dutos flexíveis. Existem trabalhos referentes à análise de tensões dos tendões nos conectores considerando o estado plano de tensões. O presente estudo dos tendões usando modelos tridimensionais, abordagem não encontrada em literatura aberta, avalia melhor a concentração de tensões nos tendões na entrada do conector. A motivação deste estudo se deve tanto à falta de informações detalhadas das tensões e deformações nos tendões na interface com o conector, como pela importância das mesmas, em componentes vitais à explotação de petróleo Offshore. / This aim of this work is to evaluate stresses which actuate on a system made up of a unbonded flexible pipe and a end fitting during static and dynamic axial loading mechanical tests. These tests are used as a means of qualification of flexible pipes. The structural design of models of end fittings were developed and patented. Preliminary static and dynamic tests with two different end fittings and a smalldimensioned riser segment were performed in a frame in view of selecting the bestperforming type. After this evaluation, the end fitting with the best performance was tested in a rig with dimensions according to Petrobras document I-ET 3500.00.6500-291-PAZ- 001 - Non standartized Prototype qualification tests of flexible pipes (2007). Tests performed in the frame and on the rig were monitored with resistance strain gages attached to wires of the external armor, on the interface with the end fitting resin, since performance of this region under fatigue is of utmost practical importance. Three-dimensional solid models were built using the Finite Element Modelling (FEM) method, as a way of validating experimental results. Comparison of results obtained from the different methodologies validated the numerical model, allowing a better understanding of the variations of stresses in the interface of the riser with the end fitting. This led to the solution of many doubts regarding fatigue performance as well as possible improvements in the design of flexible riser end fittings. Existing work published in literature considers only plane stress; the present study, based on 3D models which are not found in literature, is thought to better describe the stress concentration on the wires at the end fitting interface. The motivation of this work relies on the lack of detailed information of the stress and strain to which wires are subjected at the interface with the end fitting, as well as the importance of these in vital components for offshore oil exploration.

The research examines what drives Mergers and Acquisitions (M&As) using a theoretical and empirical approach. The theoretical part uses flexible optimal policies which adjust to changes in the market structure following a merger. The empirical part tests the major theoretical predictions to identify determinants of M&As in advanced economies. Chapters 1 and 2 consider M&As among firms in a pollution-intensive sector. Chapter 1 shows that identical polluting firms engage in M&As only if environmental policies are flexible. Chapter 2 shows that the flexibility of environmental policy increases the incentive to merge among heterogeneous firms. In addition, with flexible policy highly polluting firms have the highest incentive to merge than less polluting firms in a given sector. The empirical evidence suggests that the decision of manufacturing firms to engage in M&As is affected by environmental policy and firms may engage in merger deals in anticipation of a change in policy. Chapter 3 shows that with a flexible consumption tax firms in a bigger, more efficient country takeover firms in a smaller, less efficient country. The incentive to merge increases with the efficiency and market size of the host country. The empirical result obtained from 7 OECD countries shows that market size and firm efficiency play a major role in triggering international mergers.

Joseph Ratzinger, who led the Catholic Church as Pope Benedict XVI from 2005 to 2013, is a well-respected and published theologian. Much of his writing centers on the liturgy, and he has addressed the topic of music several times. His theological understanding of liturgical music and its application to the pipe organ together with its repertoire is the focus of this dissertation. The first two chapters deal with Ratzinger’s theological writings on the liturgy and sacred music as well as their significance for the pipe organ. Several themes emerge in his writings. These reveal Ratzinger’s understanding of the liturgy and are identified as characteristics of true liturgical music. Though he rarely speaks directly about the organ, these characteristics, namely, cosmos, logos, mystery, and history can be connected with both the instrument and its repertoire. In chapters three through five, select pieces from the masterworks of the Catholic organ tradition, Frescobaldi’s Fiori Musicali, Tournemire’s L’Orgue Mystique, and Langlais’ Livre Oecumenique, are analyzed and interpreted in light of Ratzinger’s theology. The organ has also been used as an accompanimental instrument and for improvisation in the liturgy. This is considered in chapters six and seven. In chapter eight, attention is given to the pipe organ itself, and the instrument is found to be a symbol of the same theological concepts Ratzinger associates with the liturgy. The last chapter provides a summary and indicates the implications of Ratzinger’s theology for the liturgical role of the pipe organ today. This comprehensive examination of Ratzinger’s theology of liturgical music and the pipe organ with its liturgical repertoire, which includes written compositions, accompaniment, and improvisation, reveals the relationship between them. The organ itself embodies Ratzinger’s themes of cosmos, logos, mystery, and history and is therefore the ideal liturgical instrument, indeed, the king of musical instruments. Through analysis, certain musical characteristics are discovered that can be said to exemplify elements of liturgical theology. Ultimately, Ratzinger’s liturgical theology assigns value to the historic role of the organ in the liturgy and illuminates the worth and relevance of the Church’s treasury of sacred organ music.

abstract: Evacuated tube solar thermal collector arrays have a wide range of applications. While most of these applications are limited in performance due to relatively low maximum operating temperatures, these collectors can still be useful in low grade thermal systems. An array of fifteen Apricus AP-30 evacuated tube collectors was designed, assembled, and tested on the Arizona State University campus in Tempe, AZ. An existing system model was reprogrammed and updated for increased flexibility and ease of use. The model predicts the outlet temperature of the collector array based on the specified environmental conditions. The model was verified through a comparative analysis to the data collected during a three-month test period. The accuracy of this model was then compared against data calculated from the Solar Rating and Certification Corporation (SRCC) efficiency curve to determine the relative performance. It was found that both the original and updated models were able to generate reasonable predictions of the performance of the collector array with overall average percentage errors of 1.0% and 1.8%, respectively. / Dissertation/Thesis / M.S. Mechanical Engineering 2011