In many applications, non-uniform flows are undesirable and have a negative system impact. Non-uniform flows can arise in many ways such as in geometry changes and turns in piping/ducting, as well as with lip separation in certain aircraft engine inlets at high angle of attack. These non-uniformities can come with a variety of secondary flow patterns and thus highly three-dimensional flow. In a cylindrical coordinate system, these secondary (or in-plane) velocities have tangential and radial components. The tangential velocity is typically referred to as swirl and is the component of secondary flow that has the most system impact. These systems include industrial compressors, aircraft engines, and flow metering devices. In industrial compressors and aircraft engines, swirl translates into off-design incidence angles on the blades. The off-design incidence can lead to blade stall, losses in performance, and loss in system operability. In flow metering, swirl can significantly reduce measurement accuracy, and is regulated in industries such as the oil and gas industry. In the straightening of low-speed flows with approximately constant density and axial velocity, the velocity magnitude decreases and pressure increases along streamlines. This creates an unfavorable streamwise pressure gradient that inhibits the fluids ability to remain attached to the convex suction surface of the turning vane. This suction side separation causes the flow to under turn and exit at an angle not equal to the vane's trailing edge angle. The angle measured between the vane's trailing edge and the actual exiting flow angle is referred to as the deviation. Research on specific airfoil shaped turning vanes set up in linear cascade arrangements provides experimental data detailing the deviation measured at ranges of inlet flow conditions and vane spacing. These experimental data sets indicate that deviation angles were measured to be 10 degrees or higher in large vane spacing, high design flow turning arrangements. It is evident that in order to effectively straighten flow with turning vanes, the deviation must be predicted and accounted for in the design stage. In this work, the design system of a new method of swirl mitigation is detailed and experimentally validated in a low-speed wind tunnel. The design system builds upon the fundamentals of the swirl-producing StreamVane design methods and is thus designated as the Inverse StreamVane. The complex arrangement of turning vanes in the StreamVane and Inverse StreamVane alike creates a spanwise variation of vane spacing. Calculated by a proximity approximation method, this local vane spacing, along with the local inlet flow conditions, become inputs to a derived function that predicts the local flow deviation. A root-finding method is utilized at each incremental vane section of each turning vane to converge on the design cambers that set the predicted local deviation angles equal to the local trailing edge angles. Experimental and computational results validate the design method employed with the reduction of an experimentally measured 30 degree peak paired swirl profile to a 3 degree peak, 1.01 degree rms, swirl profile. Flow angularity and loss measurements detailed at 1/2 duct diameter downstream of the 1/6 duct diameter axial length of the device introduce the Inverse StreamVane as a very effective and efficient method of swirl mitigation. / MS / Fluid flows with components in directions other than just the dominant axial direction can create complexities and undesirable effects on a variety of systems. In applications such as aircraft engines and HVAC compression systems, these secondary velocity components can lead to lower efficiencies and loss in operable range. In applications such as flow rate measurement, these secondary velocity components can lead to losses in accuracy and increased measurement uncertainty. The underline effect of such losses in these systems is undesirable increase in system costs. For these reasons, a variety of devices and efforts have been made in attempts to reduce secondary velocity components. Many methods of reducing secondary velocity components, or straightening the flow, involve the introduction of obstructions in the fluid’s path. These obstructions can create energy losses, thus reducing the amount of energy the fluid can impart, or increasing the amount of energy input required to the fluid in order to achieve the same system performance. In the presented work, the design and wind tunnel validation of a flow straightening device is detailed. The design method utilizes curved airfoil shaped turning vanes strategically placed to reduce obstruction and increase straightening effectiveness. The device is referred to as the Inverse StreamVane, as it stems from the design principles of the secondary velocity producing StreamVane TM device introduced in 2013. With the design method presented, flow straightening devices tailored to specified flow profiles can be rapidly generated. As is shown by experimental measurements in a wind tunnel, large secondary velocity components are removed by 90% or greater in very short axial distances downstream of the Inverse StreamVane. Losses at the flow regime tested are also shown to be very small downstream of the Inverse StreamVane. The work presented suggests that the design system and device has the potential to benefit a variety of industries and applications.

Orientador: Marjorie de Assis Golim / Resumo: O formaldeído (FA) é um composto químico produzido mundialmente e economicamente importante devido às suas diversas utilizações comerciais e industriais. A exposição ocupacional ao FA ocorre em uma variedade de profissões, incluindo cabelereiros. No Brasil, a utilização e/ou a adição de FA à alisantes capilares é proibido pela ANVISA, entretanto vem sendo uma prática comum, pois mesmo não apresentando FA em sua composição, esses produtos contêm outras substâncias que durante o procedimento de alisamento, promove a liberação de FA, em forma de vapor, expondo epiderme, mucosas e, principalmente vias respiratórias. O FA é tóxico para o homem, podendo levar a diversas manifestações sistêmicas em diferentes graus, tanto em indivíduos expostos esporadicamente, a exemplo dos usuários dos alisantes capilares, quanto para profissionais frequentemente expostos, sendo este risco proporcional à concentração do FA e frequência de exposição. Estudos prévios têm demonstrado diversas alterações em indivíduos expostos ao FA comparados àqueles não expostos como: elevação dos níveis de ácido fórmico na urina (produto final da metabolização do FA), dano de DNA (presença de micronúcleos e fragmentação de DNA), influência em células do sistema imunológico (natural killer, linfócitos T e B), diminuição nos níveis de glutationa (enzima envolvida na metabolização de FA), entre outros. O presente estudo objetivou avaliar se ocorre desequilíbrio no padrão de citocinas pró/anti-inflamatórias (IL-1β, IL-... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Formaldehyde (FA) is an economically relevant chemical compound worldwide due to its various commercial and industrial applications. Occupational exposure to FA occurs in a variety of professions, including hair slytlist. In Brazil, the use and / or addition of FA to capillary straighteners is prohibited by ANVISA; however, it has been a common practice, since even without FA in its composition, these products contain other substances that during the straigntening procedure, promote release of FA, in the form of vapor, exposing epidermis, mucous membranes and mainly respiratory airways. FA is toxic to humans and can lead to different systemic manifestations to different degrees, both in individuals exposed sporadically, as in the case of users of hair straighteners, and for professionals who are frequently exposed, being this risk proportional to the concentration of FA and frequency of exposure. Previous studies have demonstrated several alterations in individuals exposed to FA compared to those not exposed such as: elevation of formic acid levels in urine (end product of FA metabolism), DNA damage (presence of micronucleus and DNA fragmentation), influence on cells of the immune system (natural killer, T and B lymphocytes), decrease in glutathione levels (enzyme involved in the metabolism of FA), among others. The aim of this is study was evaluate the imbalance in the pattern of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-10, TNF-α and IL-12p70), serum chemokines (ILP... (Complete abstract click electronic access below) / Mestre

The thesis Design of the straightening machines XRK 7-200 deals with the types of straightening machines and their principles. Further, procedures for construction proposals of seven-roll straighteners with rods of 100-200 mm in diameter are described. These proposals are primarily made for upper and lower crossbeams. The thesis also presents calculations of drives and set screws.

Today is on products from the perspective of quality placed an increasing emphasis. This work is focused to the analyze of cross roll straghtening of long semifinished products with a circular cross-section. This process increased quality of semifinished products from the perspective of their curvature, because they do not reach the required limit values. Curvature of the semifinished product is due to residual stress, which is during straghtening using plastic deformation of the material redistributed and the semifinished product is leveled. This work analyzes the effect of rotation of straightening rolls on the distributiom of contact pressure between the straightening semifinished product and the roll of straightener. Author then analyzes effect of input parameters of program to straightening at the final curvature of the semifinished product. With the experience gained, then try to adjust some input parameters.

O número de swirl de um cabeçote de motor de combustão interna pode ser medido pelo método de vazão em regime permanente. Nesse método o ar é forçado através do cabeçote para diferentes aberturas de válvula. O sensor comumente utilizado nas plataformas para a medição do swirl é o do tipo ISM (impulse swirl meter) que utiliza um retificador de fluxo como o componente principal para capturar o momento angular de rotação do fluxo de ar. Esse trabalho visa encontrar as dimensões geométricas para o retificador de fluxo utilizado em sensor tipo ISM, de tal forma que esse retificador possibilite a realização das medições com a menor interferência possível no resultado final. Dezesseis retificadores de diferentes dimensões foram construídos a partir do processo conhecido como prototipagem rápida. Vários ensaios foram realizados em uma plataforma que utiliza o método de vazão em regime permanente para a medição de swirl em cabeçotes. Para todos os ensaios foi utilizando um mesmo cabeçote de motor diesel como gerador de swirl. No capítulo conclusões são apresentadas as dimensões geométricas que resultaram em menor interferência no fluxo e uma maior eficiência do sensor, bem como sugestões para trabalhos futuros. / The swirl number of a cylinder head can be measured by a steady state flow method in which air is forced through the cylinder head for different valve openings. The sensors commonly used on the swirl measurement platform are of the ISM type (impulse swirl meter) that use a flow straightener as the main component to capture the rotational angular momentum of the air flow. This study objective is to determine the geometric dimensions for the flow straightener used in the ISM sensor, which still allows the measurement but causes the least interference on the measurement result. Sixteen different flow straighteners were constructed by rapid prototyping process. Several tests were performed on a platform that uses the steady state flow method to measure the swirl number of cylinder heads. For all tests the same cylinder head was used as swirl generator. The conclusion chapter presents the geometric dimensions that caused the least interference in the flow and resulted in a greater sensor efficiency, as well as suggestions for future studies.

O número de swirl de um cabeçote de motor de combustão interna pode ser medido pelo método de vazão em regime permanente. Nesse método o ar é forçado através do cabeçote para diferentes aberturas de válvula. O sensor comumente utilizado nas plataformas para a medição do swirl é o do tipo ISM (impulse swirl meter) que utiliza um retificador de fluxo como o componente principal para capturar o momento angular de rotação do fluxo de ar. Esse trabalho visa encontrar as dimensões geométricas para o retificador de fluxo utilizado em sensor tipo ISM, de tal forma que esse retificador possibilite a realização das medições com a menor interferência possível no resultado final. Dezesseis retificadores de diferentes dimensões foram construídos a partir do processo conhecido como prototipagem rápida. Vários ensaios foram realizados em uma plataforma que utiliza o método de vazão em regime permanente para a medição de swirl em cabeçotes. Para todos os ensaios foi utilizando um mesmo cabeçote de motor diesel como gerador de swirl. No capítulo conclusões são apresentadas as dimensões geométricas que resultaram em menor interferência no fluxo e uma maior eficiência do sensor, bem como sugestões para trabalhos futuros. / The swirl number of a cylinder head can be measured by a steady state flow method in which air is forced through the cylinder head for different valve openings. The sensors commonly used on the swirl measurement platform are of the ISM type (impulse swirl meter) that use a flow straightener as the main component to capture the rotational angular momentum of the air flow. This study objective is to determine the geometric dimensions for the flow straightener used in the ISM sensor, which still allows the measurement but causes the least interference on the measurement result. Sixteen different flow straighteners were constructed by rapid prototyping process. Several tests were performed on a platform that uses the steady state flow method to measure the swirl number of cylinder heads. For all tests the same cylinder head was used as swirl generator. The conclusion chapter presents the geometric dimensions that caused the least interference in the flow and resulted in a greater sensor efficiency, as well as suggestions for future studies.