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1
Walsh, Brendan Walsh Patrick. "Rotary." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-12052008-145205/.
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Alnakar, Raran, and Danilo Catovic. "Rotary parking system." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295808.
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Automatic parking systems are intended to save a lot ofspace and create a more favourable parking experience. In this thesis the main goal was to create a functional and user-friendly rotary parking system. The system consistsof a framework, DC-motor, driveline, ultrasonic distance sensor and platforms. Most of the construction consists of plastic, the remaining parts are made of metal. The system was evaluated using two experiments, one that measured the speed of the system and the other one measuring the level of accuracy. After the first experiment, it was concluded that the system works well for the corresponding speed. The second experiment showed that improvements of the accuracy can be made.Automatiska parkeringssystem är avsedda att spara utrymme och skapa en bättre parkeringsupplevelse. I denna avhandling var huvudmålet att skapa ett funktionellt och användarvänligt roterande parkeringssystem. Systemet består av ett ramverk, likströmsmotor, drivlina, ultraljudssensor och plattformar. Majoriteten av konstruktionen består av plast, de återstående delarna är gjorda av metall. Systemet utvärderades med hjälp av två experiment, ett som mätte systemets hastighet och ett annat som mätte noggrannheten. Efter det första experimentet drogs slutsatsen att systemet fungerar bra för motsvarande hastighet. Det andra experimentet visade att förbättringar av noggrannheten kan göras.
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Alnakar, Rayan, and Danilo Catovic. "Rotary parking system." Thesis, KTH, Mekatronik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-295808.
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Automatic parking systems are intended to save a lot ofspace and create a more favourable parking experience. In this thesis the main goal was to create a functional and user-friendly rotary parking system. The system consistsof a framework, DC-motor, driveline, ultrasonic distance sensor and platforms. Most of the construction consists of plastic, the remaining parts are made of metal. The system was evaluated using two experiments, one that measured the speed of the system and the other one measuring the level of accuracy. After the first experiment, it was concluded that the system works well for the corresponding speed. The second experiment showed that improvements of the accuracy can be made.Automatiska parkeringssystem är avsedda att spara utrymme och skapa en bättre parkeringsupplevelse. I denna avhandling var huvudmålet att skapa ett funktionellt och användarvänligt roterande parkeringssystem. Systemet består av ett ramverk, likströmsmotor, drivlina, ultraljudssensor och plattformar. Majoriteten av konstruktionen består av plast, de återstående delarna är gjorda av metall. Systemet utvärderades med hjälp av två experiment, ett som mätte systemets hastighet och ett annat som mätte noggrannheten. Efter det första experimentet drogs slutsatsen att systemet fungerar bra för motsvarande hastighet. Det andra experimentet visade att förbättringar av noggrannheten kan göras.
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Dupont, Benoît. "Conception du compresseur supersonique du Rim Rotor Rotary Ramjet Engine." Mémoire, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/8823.
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La demande pour les ressources énergétiques est en hausse alors que leur disponibilité est en baisse. Dans ce contexte, l’industrie du transport et de l’énergie est à la recherche de petits moteurs efficaces et puissants et le Rim Rotor Rotary Ramjet Engine (R4E) pourrait correspondre à ces critères. Or, en ce moment, le potentiel de ce moteur est limité, car son compresseur supersonique entraîne des pertes d’efficacité lorsque le rotor tourne à son nombre de Mach tangentiel optimal qui est de 2.
Le présent mémoire compile toutes les notions requises pour comprendre le fonctionnement d’un compresseur supersonique lors de son démarrage et de concevoir le compresseur le plus approprié pour le R4E, tant en démarrage qu’en régime permanent. Pour se faire, des concepts de cascades inspirés des compresseurs et des méthodes de démarrage des moteurs ramjet actuels ont été générés et validés à l’aide de modèles analytiques. Les concepts sont par la suite essayés expérimentalement sous la forme de cascades à l’aide d’une soufflerie supersonique.
Bien que le modèle analytique montre que les cascades munies de canaux de purge soient plus performantes et plus robustes en conditions off-design, ces dernières n’ont jamais démarré lors des expérimentations même si les canaux ont été agrandis et multipliés. Ainsi, parmi tous les concepts essayés, celui qui démarre par survitesse et qui comporte des canaux de succion de couche limite à son col a donné les meilleurs résultats. Il est très stable et permet d’obtenir un ratio de pression statique de 4.25 et un recouvrement de pression totale de 89 %, pour une efficacité isentropique de 92 % à un nombre de Mach tangentiel de 2. Par contre, il est à noter qu’il n’a pas été possible de mesurer la pression totale. Elle a plutôt été estimée à partir des images de strioscopie tirées lors des essais.
Comme on ne dispose pas d’une structure permettant d’essayer le compresseur rotatif à Mach 2, il a fallu approximer l’influence de l’accélération centrifuge sur l’écoulement de la cascade et trouver un moyen d’intégrer le nouvel aubage à la roue. Un modèle permettant d’estimer les paramètres d’une couche limite se développant sur une plaque plane en rotation a permis de déduire que l’accélération transverse n’aurait qu’un effet légèrement favorable, puisqu’il permet d’amincir l’épaisseur de déplacement, réduisant ainsi les risques d’interaction en la couche limite et les chocs. Finalement, les canaux de succion de couche limite du compresseur pourraient permettre d’alimenter un système de refroidissement qui limiterait la température à la jante à 820 K.
Le R4E pourrait devenir l’avenir des systèmes de régénération électrique pour les véhicules hybrides. Il serait aussi intéressant pour une utilisation dans les petites centrales thermiques des régions éloignées. Ce grand potentiel d’utilisation provient de la grande densité de puissance du moteur, de sa simplicité et de son très faible coût de fabrication et de maintenance.
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Montesanti, Richard Clement. "High bandwidth rotary fast tool servos and a hybrid rotary/linear electromagnetic actuator." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/34987.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Includes bibliographical references (p. 541-555).
This thesis describes the development of two high bandwidth short-stroke rotary fast tool servos and the hybrid rotary/linear electromagnetic actuator developed for one of them. Design insights, trade-off methodologies, and analytical tools are developed for precision mechanical systems, power and signal electronic systems, control systems, normal-stress electromagnetic actuators, and the dynamics of the combined systems. A fast tool servo (FTS) is a high-speed auxiliary servo axis that is added to a diamond turning machine (ultra-precision lathe) to allow generating free-form non-axisymmetric or textured surfaces on a workpiece. A rotary fast tool servo produces an in-and-out motion of the tool relative to a workpiece by swinging the tool along an arc having a fixed radius. The rotary fast tool servos developed in this project were designed for diamond turning prescription textured surfaces on small spherical workpieces (diameters in the range of 10 mm or less), and are suitable for generating free-form non-axisymmetric surfaces on similar-sized workpieces. Straightforward modifications would allow them to be used on larger workpieces. These rotary fast tool servos set new benchmarks for demonstrated closed-loop bandwidth (2 kHz and 10 kHz) and tool tip acceleration (400 g).
(cont.) The first machine, referred to as the 2 kHz rotary fast tool servo, uses a commercially available moving-magnet galvanometer as the actuator (Lorentz force), and provides proof-of-principles for a flexure bearing, small diamond tool and mounting method, circuit topology for a high bandwidth current-mode amplifier, and control system design. The following closed-loop performance is demonstrated for the 2 kHz rotary fast tool servo: -3dB bandwidth of 2 kHz, 20 g tool tip acceleration at 2 kHz, maximum tool travel of 50 [mu]m PP, and tool position noise level of 10 nm PP. The 2 kHz FTS is integrated with a diamond turning machine and used to produce optical quality textured surfaces on the face and outside diameter of aluminum workpieces while operating at 2 kHz. The machining tests validate that a rotary-type fast tool servo can be used to produce optical quality surfaces on a spherical workpiece from its pole to its equator. The second machine, referred to as the 10 kHz rotary fast tool servo, incorporates the proof-of-principles from the first machine and is the vehicle for developing the hybrid rotary/linear electromagnetic actuator used in it.
(cont.) The actuator is a normal-stress variable reluctance machine with a demonstrated order of magnitude increase in the peak torque and in the ratio of peak torque divided by the electrical power at its terminals, when compared to the actuator used in the 2 kHz FTS. By integrating the tool holder directly to the moving mass of the actuator to form a single rigid body, the overall torque-to-inertia ratio for the system and the frequency of the first uncoupled-mass resonance are both increased. The following closed-loop performance is demonstrated for the 10 kHz rotary fast tool servo: -3dB bandwidth of 10 kHz, 400 g tool tip acceleration at 5 kHz, 870 g tool tip acceleration at 10 kHz (aided by a stable mechanical resonance), maximum tool travel of 70 [mu]m PP, and tool position noise level of 1.4 to 2.5 nm rms (depending on the magnitude of the bias flux used). The hybrid rotary/linear electromagnetic actuator utilizes a constant bias magnetic flux, which linearizes the torque versus drive-current relationship for the actuator and provides up to half of the torque-producing magnetic flux in the rotor/stator air gaps. The actuator is similar to the rotary actuators used to drive and sustain a resonance in a mechanical oscillator in certain electric engraving heads.
(cont.) This research is distinguished from the prior art by the ability to generate closed-loop arbitrary trajectories for the tool tip. Using a separate current-mode amplifier for each stator half allows demonstrating closed-loop control of the rotary and linear degrees of freedom that are inherent in this class of actuators. This research is further distinguished from the prior art by a magnetic circuit that substantially decouples certain magnetic flux paths when a coil is used instead of a permanent magnet to provide the bias magnetic flux. This reduces the complexity of the actuator electrical dynamics from a MIMO system to a SISO system, and allows using loop-shaping techniques with classical control theory to design the control systems. Torque control for the hybrid rotary/linear actuator in the 10 kHz FTS is independent of force control, but force control requires a torque-generating current to act as an operating point. Alternate magnetic circuit topologies that fully decouple torque and force control are described and compared. Future work that utilizes the linear mode as an active suspension for improving the performance of a predominantly rotary system is considered. Using the experience gained by designing, building, and testing the 10 kHz FTS and hybrid rotary/linear actuator, future work involving alternate concepts for the actuator is suggested for a follow-on rotary fast tool servo, and a high bandwidth steering mirror.
by Richard Clement Montesanti.
Ph.D.
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Qi, Fei. "Light-driven molecular rotary motors." HKBU Institutional Repository, 2017. https://repository.hkbu.edu.hk/etd_oa/434.
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In the past two decades, a number of artificial molecular motors have been constructed using organic molecules as components which can perform unidirectional motion. Among the best-known examples are the light-activated molecular rotary motors synthesized and analyzed in B. L. Feringa's lab. Yet there is limited understanding of the photoisomerization and thermal isomerization processes that control the speed and energy conversion efficiency of these molecular devices. The present thesis work aims at: 1) developing a computational methodology to provide the atomic and electronic details that allow for quantitative descriptions of light-activated molecular motion, 2) improving the understanding of the physical principles governing photo- and thermal-isomerization processes in specific molecular systems, and 3) proposing a new strategy of molecule design to assist experimental investigations. A key component in our methodology is the calculation of the potential energy surface (PES) spanned by collective atomic coordinates using ab initio quantum mechanical methods. This is done both for the electronic ground state, which is relatively straightforward, and for the photo-excited state, which is more involved. Once the PES is known, classical statistical mechanical methods can be used to analyze the dynamics of the slow variables from which information about the rotational motion can be extracted. Calculation of the PES is computationally expensive if one were to sample the very high dimensional space of the atomic coordinates. A new method, based on the torque experienced by individual atoms, is developed to capture key aspects of the intramolecular relaxation in terms of angular variables associated with the rotational degrees of freedom. The effectiveness of the approach is tested on specific light-driven molecular rotary motors that were successfully synthesized and analyzed in previous experiments. Finally, based on the experience accumulated in this study, a new molecular rotary motor driven by visible light is proposed to reach MHz rotational frequency.
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Roy, Matthew J. "Rotary forming of cast aluminum." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44789.
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The application of rotary forming to A356 offers a potential improvement in material use, simplified castings and ameliorated fatigue resistance. To investigate the utility of adopting this process industrially, an extensive characterization and modelling effort was undertaken.
The constitutive behaviour of A356 in the as-cast condition was assessed with compression tests performed over a range of deformation temperatures (30-500°C) and strain rates (~0.1-10/s). The flow stress as a function of temperature and strain rate was quantified via an extended Ludwik-Hollomon and Kocks-Mecking framework.
The through-process microstructural effects on A356 subjected to rotary forming at elevated temperatures was also investigated. This was conducted on material at 350°C with an industrially-scaled, purpose-built apparatus, inducing varying levels of spinning deformation. This was also conducted on commercially flow formed material with high levels of deformation at the same temperature. Macro and micro-hardness testing was used to track the changes from the as-cast and as-formed states, as well as following a T6 heat treatment. Further EDX analysis indicate that precipitation aspects of heat treatment is not appreciably affected by forming. Forming was found to principally affect the eutectic-Si particle size, resulting in a finer particle post heat treatment.
An explicit finite element rotary forming model reciprocating experimental forming conditions was developed incorporating the Ludwik-Hollomon description. This forming model was found to be computationally expensive; however, demonstrated reasonable agreement with experimental geometry and phenomena.
In evaluating the effect of forming on fatigue, multiaxial testing of A356-T6 was conducted to apprehend the basic fatigue mechanisms. Endurance limits are found to be generally governed by porosity and maximum principal stress for high cycle fatigue. Uniaxial fatigue tests of both experimentally and commercially formed material showed a 30% increase in endurance limits over unformed material, principally through mitigating porosity.
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Grieve, David G. "Computer simulation of rotary forging." Thesis, University of Nottingham, 1991. http://eprints.nottingham.ac.uk/14392/.
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This thesis presents two computer packages to simulate the rotary forging process, by means of a mathematical model. The results are displayed in a graphical and numerical manner, showing the tool movement and the tool / workpiece interaction. The first package, PATH, is shown to be capable of simulating the motions of all known rotary forging systems. Its results show the rotary forging tool path throughout a chosen process. The motions of any rotary forging system can be programed by a simple set of instructions displayed on the screen, and the results displayed quickly and graphically. The widely used motions of rocking - die rotary forging machines were investigated. From these investigations, formulae were put forward, which were shown to be capable of predicting the tool motion of any rocking - die rotary forging situation. The second package, PROFS, presents a meshed representation of the tools and workpieces used in rotary forging systems. The rotary forging tool is represented as a conic wire frame mesh, on which no forces or loads are considered to act. The workpiece is represented as a cylinder constructed from a number of hexahedral elements. The elements are treated in either a non - constant volume or a constant volume manner. The non - constant volume model workpiece is one which is simply cut away by the action of the tool on it. This model is similar to a process of 'rotary cutting'. Using the model, a technique of investigation into the progression of the contact geometries created during a real rotary forging, was developed. It enabled the progression and size of the contact geometry to be followed from start to finish of the forging cycle. No consideration of the loads or forces occurring during the process was taken into account. The constant model workpiece requires that its volume remains fixed during the simulation. This is achieved by a radial expansion of the elements of the workpiece as it is being 'deformed' by the tool. Again no consideration of the loads or forces occurring in rotary forging was taken into account. Investigations, using the model, enabled the instantaneous contact geometries, contact areas, and displaced volumes of material to be predicted during two real rotary forging processes. Results revealed the potential of PROFS, to determine areas of workpiece instability in the early stages of forging, and reveal ares of insufficient die fill. The potential of data from the simulations, to control a rotary forging machine, is discussed, and is seen as the first step towards the design and manufacture of rotary forging parts and dies by a C.A.D. - C.A.M. route. Contact areas produced during the rotary forging process are essential for any calculations of the forces and stresses occurring in the die and workpiece. The possibility of PROFS to be used as a die / design tool and in pre production trials for new parts is discussed. A physical simulation of a non - constant volume model workpiece was carried out using a 'short lead milling' technique to cut away a solid workpiece. This revealed the instantaneous contact geometries and areas of the workpiece, which were shown to be accurately predicted by PROFS using the non - constant volume. The results confirmed the accuracy and validity of the simulated instantaneous geometries, allowing a large degree of confidence to be assumed in the accuracy of the package. A data base of radial, circumferential, and custom die profiles has been built up and incorporated into PROFS. From the data base a chosen profile can be used to generate a conic meshed representation of a rotary forging die. Investigations, using a die generated from a custom profile, revealed areas of possible workpiece instability. The two packages put forward in this thesis have been shown to be capable of simulating the motions and contact geometries of the rotary forging process, and confirmed using physical and real rotary forging comparisons.
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Urs, Shravan B. R. "SCHEDULING ROTARY INJECTION MOLDING MACHINE." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1132529304.
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Heydenrych, Michael David. "Modelling of rotary kilns : proefschrift ... /." [Enschede?] : University of Twente, 2001. http://www.ub.utwente.nl/webdocs/ct/1/t00000628.pdf.
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Picard, Mathieu. "Dynamique des gaz et combustion du Rim-Rotor Rotary Ramjet Engine (R4E)." Mémoire, Université de Sherbrooke, 2011. http://savoirs.usherbrooke.ca/handle/11143/1607.
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Le Rim-Rotor Rotary Ramjet Engine (R4E) a le potentiel de remplacer les turbines à gaz de 1 MW et moins en offrant : (1) une densité de puissance de 7.6 kW/kg, soit le double des turbines à gaz actuelles, (2) une meilleure fiabilité et un moindre coût par sa pièce mobile unique et (3) une efficacité de plus de 20 %, soit similaire aux turbines à gaz de cette puissance.Le R4E convertit la grande vitesse tangentielle du mélange air-carburant, idéalement 1000 m/s, en une grande pression dans la chambre de combustion. La combustion des réactifs augmente le volume du gaz ce qui force les produits à sortir à une grande vitesse tangentielle. La poussée générée est récupérée en travail mécanique à l'arbre directement ou est convertie en électricité. Ce travail présente la conception de la géométrie des propulseurs à l'aide d'un modèle 1D généralisé basé sur l'analyse préliminaire, ainsi que la validation expérimentale d'un prototype faisant la preuve de concept du R4E à travers 5 étapes principales s'étendant sur 2 versions du prototype : (1) la friction aérodynamique, (2) l'écoulement dans le moteur, (3) l'allumage, (4) la combustion et (5) la démonstration de la puissance nette des ailettes. La friction aérodynamique de la paroi externe du Rim-Rotor dépasse de 35 % les modèles actuels ce qui en fait le mécanisme de perte le plus important.Le débit massique dans le moteur est de 30 % inférieur à la valeur estimée par le modèle 1D pour la géométrie testée. La puissance de trainée des statoréacteurs sans combustion mesurée est en ligne avec la puissance prédite pour un débit massique corrigé expérimentalement. En ce qui concerne la combustion dans le moteur, le champ centrifuge extrême domine le mécanisme de propagation de la flamme. Un modèle simple de flottaison est utilisé pour prédire la longueur du front de flamme, représentant les produits chauds qui ont tendance à"flotter" sur les réactifs froids. Un modèle numérique est élaboré pour valider la propagation de la flamme jusqu'à une accélération centrifuge de 1.1 million de g et montre une bonne corrélation avec le modèle simple. Une efficacité de combustion de 85% est démontrée avec un second prototype pour une accélération centrifuge jusqu'à 284 000 g, soit 25 fois supérieures à la plus grande valeur testée dans la littérature. Une fois la combustion stabilisée, ce prototype a été en mesure de produire une légère poussée, une première pour les moteurs à statoréacteur rotatif.
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Rancourt, David. "Analyse structurelle et validation expérimentale d'un Rim-Rotor Rotary Ramjet Engine (R4E)." Mémoire, Université de Sherbrooke, 2011. http://savoirs.usherbrooke.ca/handle/11143/1612.
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Le Rim-Rotor Rotary Ramjet Engine (R4E) est un moteur très haute densité de puissance utilisant des statoréacteurs en rotation pour produire un couple à grande vitesse angulaire.Le design structurel d'une première génération de R4E est présenté dans ce mémoire ainsi qu'une validation expérimentale avec combustion haute température. Ces travaux s'imbriquent dans un programme de recherche où l'objectif ultime est de démontrer expérimentalement qu'il est possible de produire de la puissance positive de ce type de moteur. La structure principale du moteur est basée sur l'utilisation d'un Rim-Rotor, un anneau de Carbone-PEEK unidirectionnel, qui reprend partiellement le chargement des propulseurs en compression. Un moyeu en aluminium en une pièce inclut les propulseurs et supporte le système d'allumage inductif intégré à la structure. Ce dernier a été caractérisé indépendamment afin de connaître l'effet des paramètres tels la distance entre les électrodes sur la puissance et l'énergie des étincelles.Le concept final proposé pèse 76 g, ne contient que 5 pièces dans un assemblage unique et peut résister à une vitesse tangentielle de 330 m/s (120 krpm) au niveau des propulseurs lors d'une combustion d'hydrogène de 1 sec. Un autre concept présenté est conçu pour résister 560 m/s (200 krpm) pour des durées de combustion très courtes, sans échauffement significatif des composants. Un modèle structurel analytique est proposé et validé par un modèle numérique ainsi que des essais expérimentaux sans combustion réalisés jusqu'à 188 krpm sans rupture.Le prototype conçu pour la combustion est validé par rapport à ses paramètres de conception et une rupture des pales de turbine survient tel que prédit par le modèle couplé thermique-structurel numérique. Les recherches ont démontré que le concept d'un R4E est viable et qu'il a le potentiel d'atteindre une vitesse tangentielle de près de 1000 m/s en utilisant des matériaux disponibles aujourd'hui. Les dissimilitudes d'expansion thermique entre les composantes, la différence de rigidité entre les pièces de l'assemblage ainsi que le transfert de chaleur vers le Rim-Rotor ont été identifiés comme des considérations importantes pour les futurs concepts de R4E.
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Tackie, Emmanuel Nii. "Elutriation of particles from rotary kilns." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/27549.
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The elutriation of fine materials from the solids bed in rotary kilns was studied in a laboratory scale steel cylinder of 0.2m in diameter and 2.4m in length. The cylinder was charged with a batch of fine alumina particles having a mean size of 64jum and the average elutriation rate measured at different air flow rates, rotational speeds and percentage of solids fill. All measurements were done at room temperature. To show the effect of fines concentration and segregation in the solids bed, a binary mixture of fine alumina and coarse Ottawa sand was used. Local dust concentration profiles were measured in the freeboard through a probe equipped with a filter.
Design factors such as the geometry of the kiln exit dams, were found to influence dust carryover into the cleaning equipment by accelerating the flowing gas and or obstructing the flow of solids in the gas phase. Wall roughness and imperfections also affected elutriation especially at higher rotational speeds by exposing trapped fines directly into the flowing gas.
Dust concentration measurements revealed that most of the solids in the gas phase travelled in saltation within about 2 cm above the bed surface. With the wall effect eliminated by an insert, increasing the rotational speed was found to exhibit a negative effect on the elutriation rate. Dust concentrations were higher in the gas phase above the lower edge of the rotating bed than at the upper edge or midpoint. However, while the concentration above the rest of the bed remained fairly constant with increased rotational speeds, at the lower edge of the bed it decreased.
Banding segregation occurred in the beds composed of fine and coarse particles. Elutriation increased with the number of fine bands formed which was proportional to the concentration of fines. The location of the bands from the exit also influenced elutriation. Saltating particles returning to the bed close to the exit had a better chance of ejecting other particles if they landed on fine bands than they would if they landed on coarse bands.
Gas velocity exhibited the strongest influence on elutriation rate. A correlation of experimental results showed a velocity dependence of U⁶ regardless of initial fines concentration in the bed.
An entrainment mechanism has been formulated based on the collision of saltating particles on the solids bed. Subsequently, a simple mathematical model was developed to describe the influence of the operating variables on elutriation. The model predictions were verified with the experimental data and the scanty data in the literature. The model requires knowledge of the saltation height and the threshold shear stress for particle movement. Model predictions for typical industrial kilns are presented. The predictions are in fairly good agreement with values reported in a survey of industrial kiln operations made prior to the experimental program, given that the effect of kiln internals was not accounted for in the model.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Yliniemi, L. (Leena). "Advanced control of a rotary dryer." Doctoral thesis, University of Oulu, 1999. http://urn.fi/urn:isbn:9514252810.
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Abstract
Drying, especially rotary drying, is without doubt one of
the oldest and most common unit operations in the process industries.
Rotary dryers are workhorses which are easy and reliable to operate,
but neither energy-efficient nor environmentally friendly. In order
to conform better to the requirements of modern society concerning
working conditions, safety practices and environmental aspects,
the development of control systems can provide opportunities for
improving dryer operation and efficiency.
Our in depth understanding of rotary drying is poor, because
it is a very complex process that includes the movement of solids
in addition to thermal drying. Thus even today rotary dryers are
controlled partly manually, based on the operator's "eye" and
experience, and partly relying on conventional control methods.
The control of a rotary dryer is difficult due to the long time
delay, which means that accidental variations in the input variables
can disturb the process for long periods of time before they are
reflected in the output variables. To eliminate such disturbances
at an early stage, increasing interest has been shown in more sophisticated
control systems such as model-based constructs, fuzzy logic and
neural nets in recent years. Although it has proved difficult and
time-consuming to develop model-based control systems, due to the
complexity of the process, intelligent control methods based on
fuzzy logic and neural nets offer attractive solutions for improving
dryer control. These methods make it possible to utilize experience,
knowledge and historical data, large amounts of which are readily
available.
The aim of this research was to improve dryer control by developing
new hybrid control systems, one consisting of a fuzzy logic controller
(FLC) and PI controller and the other of a three-layer neural network
(NN) and PI controller. The FLC and NN act as supervisory controllers
giving set points for the PI controllers. The performance of each
was examined both with simulations and in pilot plant experiments.
The pilot plant dryer at the University of Oulu closely resembles
a real industrial situation, so that the results are relevant.
Evaluation of these results showed that the intelligent hybrid controllers
are well suited for the control of a rotary dryer, giving a performance
in which disturbances can be eliminated rapidly and operation of
the dryer can thereby be improved, with the aim of enhancing its
efficiency and environmental friendliness.
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Barr, Peter Vernon. "Heat transfer processes in Rotary kilns." Thesis, University of British Columbia, 1986. http://hdl.handle.net/2429/26772.
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An experimental investigation of rotary kiln heat transfer processes was carried out and a unified heat transfer model developed to describe the individual processes and their interaction.
A 0.406 m ID by 5.5m refractory lined pilot kiln firing natural gas was utilized for a series of 23 heat transfer trials. Limestone, petroleum coke and two Ottawa sands were heated using a wide range of firing rates while rotation rate, kiln inclination, kiln loading and bed depth were held nearly constant. The bed material was in the rolling mode for all trials. Measurements were made to obtain the net heat transfer rates for the bed material, the freeboard gas, the refractory wall and, unique to the study, the heat flux at the inside wall surface as a function of circumferential position.
High rates of net heat input to the bed material, Q[sub b], which occurred very near to the kiln entrance, were found to decline quickly
with axial distance and, for an inert bed, the ratio of Q[sub b], to Q[sub ss], the
rate of energy loss through the kiln wall, tended toward the ratio of the exposed bed surface area to the exposed wall surface area. At the onset
of the limestone calcination reaction Q[sub b], increased sharply without a
corresponding increase in Q[sub ss]. Over the fully instrumented portion of the
kiln, which extended from 1.32m to 5.0m, the rate of heat transfer from the covered wall to the bed, Q[sub cw →cb], was < 30% of the rate to exposed bed surface from the freeboard. With an inert bed the net exchange Q[sub cw →cb], was
found to decline with axial distance and negative values were encountered beyond the kiln mid-point. The onset of bed calcination reversed this
trend and positive values of Q[sub cw →cb], were always recorded in the
calcination zone.
The temperature of the bed material and the inside wall surface were found to be closely-coupled and the actual temperature difference could not be determined due to the limitations of the measuring technique. The onset of bed calcination was always characterized by significant increases in both the net heat input rate to the bed material and the amount of temperature cycling at the inside wall surface.
A zone-type real gas model was developed for the radiative heat
exchanges in the freeboard and the results presented in the form of
radiative heat transfer coefficients. For the pilot kiln, firing at 10%
excess air, the coefficient for radiative heat transfer from the freeboard
gas to the exposed wall or bed surfaces was calculated to range from 2
15 →55 W/m²K for gas temperatures from 800 →1800 K. Model predictions for a prototype kiln of 4 m ID indicated an increase in the gas to surface radiation by a factor ~ 3.
The coefficients for radiative exchange among the freeboard surfaces in the pilot kiln were significantly larger than for the gas to surface exchange while, in the prototype, they were of comparable magnitude. For the inert bed trials the convective component of the freeboard surface heat flux was calculated by subtracting the calculated radiative contribution from the net surface flux. Convection to the exposed bed surface was found to be enhanced relative to the exposed wall surface although less than reported previously. Coefficients for heat transfer between the covered wall and covered bed were shown to be significantly reduced in a refractory lined kiln relative to an unlined metal drum.
A finite difference model of the refractory and bed material, incorporating the derived heat transfer coefficients, was verified using the pilot kiln data and extended to examine the relationship existing among the heat transfer processes at any kiln cross-section. Both the close-coupling of the pilot kiln bed and wall temperatures and the high rate of net bed heat input occurring near the kiln entrance and in the presence of a calcining bed were explained by the unified model. Model predictions were obtained for a 4m ID prototype kiln and aspects of kiln thermal performance identified which have important repercussions for the operation of rotary kilns.Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate
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Bosco, Bruno, and Jimmy Larsson. "Development of a Rotary CNC System." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-177373.
Full textAbstract:
The Rotary CNC system is a novel way to position a tool in the XY-plane. The system is meant to be used in areas such as 3D-printing, laser cutting, CNC milling and other rapid prototyping equipment. Benets include lower production cost, less moving parts and a small physical footprint. This thesis has provided a "Proof of Concept" prototype of the Rotary CNC system. It has been shown that the system is a viable alternative to current CNC system designs in the eld of PCB routing.
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Karantonis, Dean Electrical Engineering & Telecommunications Faculty of Engineering UNSW. "Control of a rotary blood pump." Publisher:University of New South Wales. Electrical Engineering & Telecommunications, 2008. http://handle.unsw.edu.au/1959.4/43474.
Full textAbstract:
Implantable rotary blood pumps (RBPs) are an emerging technology designed to provide sufferers of heart failure with a viable treatment option which improves their medical prognosis and quality of life. The broad aim of this thesis is to address the need for a pump control strategy, and develop a solution whereby the implant recipient??s physiological requirements are continuously monitored in a non-invasive manner and met with an appropriate response by the RBP. Employing only the non-invasive signal of instantaneous pump impeller speed to assess flow dynamics, five physiologically significant pumping states have been identified in acute ex vivo porcine experiments (N=6). Two broader states, corresponding to normal and ventricular suction conditions, were readily discernable in clinical data from human implant recipients (N=10). Employing a classification and regression tree (CART) model, an automated real-time algorithm was developed to detect pumping states with a high degree of sensitivity and specificity. Both suction and normal states were detected without error in data from the animal experiments, and with a peak sensitivity/specificity, for detecting suction, of 99.11% / 98.76% in the human patient data. Algorithms to non-invasively estimate RBP flow and differential pressure in both steady- and pulsatile-flow environments were developed. Taking the pump feedback signals of speed and power, together with the blood haematocrit (or equivalent viscosity) level, as input parameters, several estimation models were developed via polynomial surface fitting and/or system identification methods, yielding clinically acceptable results (mean flow errors of 3.09% and 5.49%, and mean pressure errors of 1.80% and 6.47%, for the steady- and pulsatile-flow cases, respectively). An RBP control algorithm based on a non-invasive indicator of the implant recipient??s activity level has been proposed and evaluated in a software simulation environment. An Activity Level Index (ALI) forms the basis of an adaptive control module operating within a hierarchical multi-objective framework which imposes several constraints on the pump??s operating region. Three class IV heart failure cases of varying severity were simulated under rest and exercise conditions, and a comparison with other popular RBP control strategies was performed. Simulations of the proposed control algorithm exhibited the effective intervention of each constraint, resulting in an improved flow response and the maintenance of a safe operating condition, compared with other control modes.
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Paone, Matthew Paul. "Rotary-axial spindles for precision machining." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/18715.
Full textAbstract:
This thesis presents the design, analysis, fabrication, instrumentation, and control of a new type of machine tool spindle. Its primary contributions include the design and experimental demonstration of: two rotary-axial spindle prototypes, MIMO current control for a 1 kW linear power amplifier, sensorless rotary motion feedback, a novel method for increasing ADC resolution, and loop-shaping motion control systems.
Some machining operations, such as face grinding, require rotational and feed motion to remove material. Conventional machine tools accomplish this by attaching a spindle which has thrust and journal support to a feed drive which also has thrust and lateral support systems. In modern machine design, the trend is towards increasing the stiffness of each individual element. However, the inherent serial duplication of support presents a fundamental limitation to stiffness and precision.
The rotary-axial spindle architecture alleviates this problem by discarding the feed drive and spindle thrust bearing, replacing them both with a high force electromagnetic actuator. This provides millimeter range stroke for the spindle shaft, resulting in a single inertial element capable of both rotary and axial motion. This topology has several advantages. It allows kHz range bandwidth and hundreds of N/μm dynamic stiffness, improves acceleration, reduces structural bending moments, and eliminates thermal effects of fluid thrust bearings.
Two prototypes are developed to demonstrate this technology. The first is a small scale rotary-axial spindle. Driven by a four-channel 1 kW linear power amplifier with decoupled current loops, the magnetic thrust bearing can handle 600 N peak axial loads over a 1 mm stroke. A novel method for increasing ADC resolution achieves sub-5 nm RMS positioning noise. Loop shaping compensation of the position loop results in 100 N/μm minimum dynamic stiffness and 2.6 kHz closed loop bandwidth. To control the spindle speed, a sensorless rotary motion feedback algorithm was developed. It produces results equivalent to a 1000 line rotary encoder. The second prototype is a full size machine tool. It demonstrated 6 kN continuous axial load capacity, 340 N/μm minimum dynamic stiffness, 800 Hz bandwidth, and 7 nm RMS positioning noise over a 1.5 mm stroke.
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Peck, Jonathan Philip. "Performance monitoring of rotary blasthole drills." Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75895.
Full textAbstract:
Rotary blasthole drills operating in a western Canadian surface coal mine were instrumented with microprocessor-based monitoring equipment. During routine production drilling, the performance parameters of penetration rate, torque, rotary speed, pulldown and bailing air pressure were monitored at sampling intervals of 10 centimeters (4 inches). The acquired digital data were subsequently correlated with both geological and geomechanical rock properties permitting a detailed examination of machine-rock interaction. The results from a statistical analysis of the drill data identified unique ranges of performance parameters for the sandstone, siltstone, mudstone and coal units encountered at the mine. Correlation of these ranges with geophysical logs in the monitored boreholes, enabled a further calibration of drilling parameter variation to rock type. A relationship between drill performance parameter responses and rock compressive and shear strength was established. This correlation demonstrated the possibility of estimating rock strength properties based on drill performance data. Trend analysis techniques applied to the monitored drill data permitted a further understanding of the nature of tricone bit wear for the particular study environment. The applications of drill monitoring techniques are illustrated in terms of geological exploration, mine planning, tricone bit selection and wear evaluation, and drill automation and control.
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Binkley, Jeremiah, Michael Moreno, and Ronald Zenga. "Minimum NSS to Select Rotary Wing." Thesis, Monterey, California. Naval Postgraduate School, 2008. http://hdl.handle.net/10945/7050.
Full textAbstract:
EMBA Project ReportEXECUTIVE SUMMARY: The Navy and Marine Corps Rotary-wing community is experiencing unprecedented expansion while becoming more technically complex than ever before. As a result, the quality of pilots required by each Rotary-wing community has increased as well. Currently, the only pipelines that require a minimum Navy Standard Score (NSS) for selection are: USMC Jet (52); Navy Tailhook (50); and USMC Tilt-rotor (40). The remaining pipelines, E6 (Navy only), Multiengine, and Rotary-wing do not require a minimum NSS for selection. Traditionally, students who were not selected for a community with an NSS cutoff were selected into E6, Multi-engine, or Rotary-wing, with Rotary-wing receiving the lowest performers. This method of selection, while far from scientific, was accepted due to the fact that a Naval Flight Student (NFS) had to achieve a minimum NSS of 35 to advance from Primary Flight training. With the implementation of Multi-Pilot-Training- Syllabus (MPTS) in both Primary (2000), and Advanced Flight Training (2004), the minimum NSS requirement to advance from Primary Flight Training was removed. To ensure the lowest attrition rate possible without sacrificing the quality of students selected for rotary-wing, the consultants on this study sought to determine whether there should be a minimum NSS to select a NFS for the rotary-wing pipeline. This study analyzed data for a three-year period for students who selected Rotary-wing. Data for NFSs who were attrited for deficient performance was analyzed to determine their median and average NSS. The median and average NSS of a Helicopter Advanced training flight attrite was 35 with a standard deviation of 6.17. If a minimum NSS of 35 is applied it would have reduced the flight attrites by 21 students, or 55 percent, and overall attrition by 31 percent. This would have also resulted in a loss of 148 NFS over three years. Although applying a minimum NSS one standard deviation above the median would have reduced the number of flight attrites by 89 percent, it would also have adverse effects on student production by eliminating 432 students over the three-year period. Conclusions • This study serves as the starting point to transform a historically anecdotal argument on the validity of NSS correlation to NFS performance into an empirical and analytical discussion. • The statistical data supports establishing a minimum NSS of 35 to select Rotary-wing. Recommendations • Conduct additional research to determine the validity of establishing a minimum NSS for selecting Rotary-wing and determine the placement of lower performing NFSs. • Fleet Replacement Squadrons establish a database to record individual student performance in order to historically compare students.
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Chargin, David Anthony 1974. "Rotary fast tool servo component design." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9403.
Full text
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Lam, Basil Pui Man. "Convective heat transfer in rotary kilns." Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613325.
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Xu, Guoda, John Bartha, Sean Zhang, Wei Qiu, Freddie Lin, Stuart McNamee, and Larry Rheaume. "Electro-Optic Hybrid Rotary Joint (EOHRJ)." International Foundation for Telemetering, 2000. http://hdl.handle.net/10150/606501.
Full textAbstract:
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, CaliforniaAn advanced electro-optic hybrid rotary joint (EOHRJ) has been developed in Phase II of an AF SBIR effort with Physical Optics Corporation (POC) to replace cable wrap structure for multi-channel rotation-to-fixed (RTF) signal transmission. The EOHRJ meets AFFTC and other range special needs with a generic, high performance, rotary joint solution. At the moment, we have successfully installed and tested the EOHRJ on our KTM tracker system with the following capabilities: 1) able to accommodate hundreds of transmission channels, including electrical power, control, feedback, and low-speed signals; 2) able to accommodate multiple channel, high data rate (over gigabits per second), and bi-directional signal transmission; 3) able to be reliable for harsh environmental operation, adaptive to stringent sized requirement, and accommodating existing electrical and mechanical interfaces. The completed EOHRJ contains three uniquely integrated functional rings. The first and the outmost one is power ring, which provides RTF transmission channels for over 50 high voltage and high current channels. The second and the middle one is low speed electrical signal ring, which provides RTF transmission for over hundred control, feedback, and low speed data signals. The third and the inmost one is optical fiber slip ring, which, incorporating with current advanced signal multiplexing technologies (either time division or wavelength division multiplexing ) is able to provide multiple channel, high data rate, and bi-directional signal transmission. At the moment, the prototype module of the tree-layer EOHRJ has been successfully assembled in Air Force’s tracker system, and is providing a satisfactory performance. This paper presents our joint work on this project.
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Dunn, Wiley E. "Rotary Head Recorders in Telemetry Systems." International Foundation for Telemetering, 1989. http://hdl.handle.net/10150/614666.
Full textAbstract:
International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, CaliforniaAlthough magnetic recording devices employing rotary head technology have been around for many years, specific products were not developed with the bit error performance to satisfy the instrumentation recorder needs of the telemetry community. Only recently have a number of new products and new product development programs materialized which offer positive indications that telemetry systems will soon benefit from the higher data rates and storage capacities. The lack of standards in development of rotary head technology has led to development of a variety of design approaches by various manufacturers and system designers. If this trend continues, the telemetry community will not enjoy the media compatibility which has contributed so much to the success of the IRIG instrumentation recorder. The ability to remove a tape recorded on one vendors recorder and replay the tape on a different ground station containing a second vendors recorder is a capability that should be retained with the advent of the new machines. Two standards have evolved defining tape characteristics and the format of information on tape for instrumentation rotary head recorders. For the instrumentation tape media to be truly transportable between telemetry ground stations, standard signal and data formal interfaces must also be developed.
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Piernik, Magdalena. "Kultura organizacyjna klubów Rotary w Polsce." Doctoral thesis, Katowice : Uniwersytet Śląski, 2007. http://hdl.handle.net/20.500.12128/5115.
Full textAbstract:
Niniejsza praca traktuje o kulturze organizacyjnej. Podjęcie takiej tematyki jest
naturalną konsekwencją moich wcześniejszych zainteresowań – socjologią organizacji
i zarządzaniem zasobami ludzkimi. Wielokrotnie podczas rozważań na temat roli
człowieka w organizacji miałam wrażenie, że aby w pełni ją zrozumieć warto spojrzeć
na organizację przez pryzmat kultury. Wprawdzie kultura organizacyjna jest trudna do
wyabstrahowania i zdefiniowania, wręcz nieuchwytna, jednak niezwykle istotna.
Analizowane zagadnienie traktuję jako „inną grupę soczewek, przez którą
można oglądać organizację”1. Jej znaczenie zostało już docenione zarówno przez
teoretyków, jak i praktyków życia gospodarczego. Stąd w ostatnich latach zauważyć
można spore zainteresowanie tematyką kultury organizacyjnej. Badacze skupiają się
jednak głównie na kulturach przedsiębiorstw. Stowarzyszenia pozostają wciąż słabo
zbadane. Dlatego uważam je za ciekawy przedmiot badań.
Moim zamiarem badawczym było pokazanie problematyki kultury
organizacyjnej w polskich klubach Rotary. Praca stanowi fotografię kultury tej
organizacji z 2005 roku. Istnieje kilka powodów takiego wyboru przedmiotu badań.
Motywem osobistym była inspiracja mojego taty, który jest rotarianinem i
wielokrotnie opowiadał mi o klubie, do którego należy. Uznałam tę organizację za
nowe w Polsce i ciekawe zjawisko. Kluby Rotary są interesujące dla badacza kultury
organizacyjnej ponieważ, inaczej niż w przedsiębiorstwach nastawionych na zysk,
gdzie przeważają więzi rzeczowe, cechuje je wysoka dbałość o stosunki
międzyludzkie i silna więź towarzyska. Interesujące jest, czy prawidłowości
zaobserwowane przez badaczy przedsiębiorstw zachodzić będą także w kulturze
stowarzyszenia. Ponadto kluby Rotary skupiają znaczących przedsiębiorców i ludzi
wybitnych w swoich zawodach. Można więc przypuszczać, że istnieją związki
pomiędzy ich kulturą organizacyjną a normami kulturowymi polskiego biznesu.
Rozprawa doktorska ma charakter teoretyczno – empiryczny. Składa się z
pięciu rozdziałów. Pierwszy wyjaśnia pojęcie kultury organizacyjnej. Punktem wyjścia jest rozumienie organizacji jako systemu społecznego. Dalej następuje przegląd
definicji kultury organizacyjnej oraz szczegółowa analiza definicji autorstwa Edgara
Scheina. Omówiono także przejawy kultury organizacyjnej oraz jej wymiary i
typologie w ujęciu różnych autorów. Rozdział drugi opisuje proces tworzenia się
kultury w organizacji; funkcje, jakie spełnia; jej związki z innymi elementami
organizacji i kulturą narodową.
Rozdział trzeci stanowi krótką prezentację Rotary. Zaczynam od omówienia
samej formuły klubu. Przedstawiona została historia organizacji, jej działalność,
struktura klubu, przyjęty sposób zarządzania i podejmowania decyzji. Szczególną
uwagę zwracam na kwestie związane z członkowstwem w klubie Rotary – prawa i
obowiązki, jakie z tego faktu wynikają.
Kolejny, czwarty rozdział prezentuje metodologiczne aspekty postępowania
badawczego. Ostatni, najbardziej obszerny, przedstawia zgromadzony podczas badań
własnych materiał empiryczny. Kulturę organizacyjną polskich klubów Rotary
analizuję w oparciu o jej sześć wymiarów wyodrębnionych podczas pierwszej,
eksploracyjnej fazy badań. Opisowi każdego z wymiarów poświęcony został jeden
podrozdział.
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Smith, Wayne Anthony. "Commissioning a 400 Hz rotary inverter." Master's thesis, University of Cape Town, 2009. http://hdl.handle.net/11427/9226.
Full textAbstract:
Includes bibliographical references (leaves 113-115).This dissertation covers the commissioning and testing of an aircraft's constant frequency alternator as the power supply for the Blue Parrot radar. The Blue Parrot is an X-band radar which forms part of the navigation and weapon-aiming system onboard the Buccaneer S-50 SAAF aircraft. The radar set uses a source of three-phase power at 400 Hz, which the constant frequency alternator can supply with the aid of certain auxiliary systems. The auxiliary systems include a prime mover, blower fan and a telemetering system. The prime mover has high starting currents which were reduced significantly by the use of a soft-starter. During testing, the constant frequency alternator started overheating and a blower fan was selected based on its thermal requirements. Significant cooling of the constant frequency alternator's case temperature was achieved by the use of a blower fan and shroud. The generator control unit monitors and regulates all parameters on the unit except for case temperature and blower fan pressure. A telemetering system was designed and built to monitor and display these parameters.
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Wilson, Miriam Ruth. "An autonomous chemically-fuelled rotary motor." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/an-autonomous-chemicallyfuelled-rotary-motor(0383eb87-ae6a-49e8-9a14-4406de0b5b90).html.
Full textAbstract:
Biological processes commonly use molecular motors to drive chemical systems away from equilibrium thus enabling work to be done. This has inspired efforts to create synthetic rotary motors which mimic the key properties of their biological counterparts, namely autonomy and directionality with the use of a chemical fuel. Thus far, attempts to combine all three properties in a synthetic rotary motor have proven unsuccessful. This thesis describes the design, synthesis and operation of an autonomous, chemically-fuelled, directional rotary motor. In this two-compartment [2]catenane an information ratchet mechanism operates. Directional transport of the small macrocycle around the larger one is promoted by an acylation reaction using a sterically demanding pyridine-based catalyst. To achieve autonomy, conditions for a one-pot, directional, de-acylation/re-acylation reaction were developed. Under autonomous operation conditions the macrocycle displacement was followed by 1H NMR. Chapter One describes the previous strategies that have been employed to realise unidirectional rotary motion in synthetic systems and aims to give the reader an overview of the relevant literature in the field of synthetic rotary motors. Chapter Two describes the concept and design of the project. Previous work which formed the basis for this research is also discussed. The synthesis and successful operation of a molecular information ratchet fuelled by chemical energy is reported. Chapter Three describes the first autonomous, synthetic rotary motor fuelled by chemical energy. The autonomous nature of the operation is determined by 1H NMR, mass spectrometry and HPLC.
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Chabak, Kelson D. "Conceptual study of rotary-wing microrobotics." Wright-Patterson: Air Force Institute of Technology, 2008. http://handle.dtic.mil/100.2/ADA487086.
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Yliniemi, Leena. "Advanced control of a rotary dryer." Oulu : University of Oulu, 1999. http://herkules.oulu.fi/isbn9514252810/.
Full textAbstract:
Originally presented as the author's thesis.Title from Web page (viewed June 23, 2003). Originally published in print: 1999. (Acta Universitatis Ouluensis. C, Technica ; no. 138). Includes bibliographical references.
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Gousset, Sandrine. "Sociabilités bourgeoises et investissements "philanthropiques" : une approche par les clubs Rotary." La Rochelle, 2004. http://www.theses.fr/2004LAROD009.
Full textAbstract:
Cette thèse porte sur les clubs Rotary pris comme “objet carrefour” et étudiés sous divers angles, notamment comme espace de sociabilité bourgeoise et espace politique à la fois national et transnational. Elle vise en particulier à faire progresser la connaissance des sociabilités bourgeoises. La thèse comporte cinq parties consacrées respectivement à la spécificité de l'objet et aux difficultés à l'approcher, au recrutement et aux caractéristiques de cette population, à sa sociabilité, aux liens entre sociabilité et politisation, et à la dimension philanthropique et internationale de l'action rotarienne. L'auteure s'appuie sur un travail de terrain de quatre ans, avec une véritable immersion quasi ethnographique dans le milieu, et utilise diverses approches théoriques pour étudier cet objet longtemps ignoré des sciences politique et socialesThe main object of this thesis are Rotary clubs taken as multiple features topic and studied from different points of view particularly as a matter of bourgeois sociability and as a national and transnational political object. Its central purpose is to develop the understanding of bourgeois sociability. The thesis is divided in five parts dedicated respectively to the specificity of the object and difficulties that have been encountered, membership and characteristics of this population, sociability, relations between sociability and politics, and the philanthropic and international dimension of Rotarian actions. The author has been working on the field for four years, in an almost ethnographic approach, and uses diverse theoretical points of view to study this object that has been ignored from political and social sciences until now
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Suffridge, Calvin Buford. "Cleaning Efficiency of Nickel Titanium GT and .04 Rotary Files when used in a Torque Controlled Rotary Handpiece." VCU Scholars Compass, 2002. https://scholarscompass.vcu.edu/etd/5533.
Full textAbstract:
This study determined if the cleaning efficiency of NiTi rotary files in an endodontic electric handpiece using a no torque control setting was superior to that obtained when using the torque control feature. Fifty extracted human anterior teeth with straight canals were divided into two groups of 20 and two control groups of 5. Canals were instrumented with GT and .04 Profile NiTi files until a size 35 advanced to working length. Samples were sectioned, the apical 6 mm of the canal was photographed (x20) and projected onto a 3 x 4 foot grid with squares measuring 0.5 inches each. Total debris was the percentage of the number of squares containing debris versus the total number of squares. Results showed that the teeth in the torque controlled group showed an average of 24.99% debris vs. 15.55% for the teeth in the no torque group. The difference was not statistically significant.
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Köseoğlu, Seda, and Hasan Parlak. "Capacity calculator of rotary draw tube bending." Thesis, Linnéuniversitetet, Institutionen för teknik, TEK, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-19807.
Full textAbstract:
Plastic deformation of tubes can be achieved in numerous ways. One of the most useful type is CNC tube bending machines which is used in many industries such as aerospace, automotive, HVAC systems and so on. It is important that all components of system should mate properly after producing and because of this bend shaping requires sensitive operation on each components to ensure regularity of production processes with high quality end-product. Thus, the CNC tube bending industry to become widespread. However it brings some troubleshooting like wrinkling, springback, breakage and ovalisation. This failures depends on geometry of the material such as bending radius, tube thickness and also friction factor between dies and the tube. Effects of all parameters should be examined before generating the theory for a best solution. Therefore, prediction of the required moment for the proper bending process with low cost and shortened production time is needed. All of these requirements can be achieved through a C++ form application program.
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Wallin, Johan. "Tribological testing of rotary drill bit inserts." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-179970.
Full textAbstract:
The aim of this thesis work was to design and evaluate a wear test method for cemented carbides inserts used in rotary drilling. An appropriate in-house wear test method would provide a better understanding of the wear mechanisms limiting tool life in real drilling. The test method should be easy to use and be able to distinguish between wear of insert materials with different microstructure and properties. The literature study showed few published articles about wear tests and mechanisms concerning rotary drill bit inserts. These methods included two standard wear tests; ASTM G65 and ASTM B611. Furthermore, a modified ASTM G65 test was found as well as an impact-abrasion test. In this work the modified ASTM G65 test, using a rock counter surface, was evaluated in order to understand if the method would mimic the wear of cemented carbides used in rotary drilling. The test method was further developed and showed high repeatability. Measured weight losses showed that the test could distinguish between two common rotary grade materials with a small difference in hardness but with different microstructures. The wear of the tested materials was analyzed with scanning electron microscopy and compared with rotary drill bit inserts collected from the field. The modified test method proved able to produce wear by mechanisms very similar to those found on field worn inserts. Identified wear mechanisms included cracking, fragmentation and spalling of WC grains as well as embedded fragments of WC grains on the surface. In addition, the binder phase was removed and adhered material from the counter surface was detected.
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Gustafsson, Thomas. "Modelling and control of rotary crane systems." Doctoral thesis, Luleå tekniska universitet, Signaler och system, 1993. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16918.
Full textAbstract:
This thesis is devoted to the modelling and control of rotary crane systems. The goal is to design a control system that assists the operator to move a cargo without oscillations and to correctly align the cargo at the final position. The control system is divided into two independent parts, one dealing with the alignment of the load with the aid of a power swivel or a cargo rotating device, and a second that deals with the elimination of load oscillations. Both design and implementation of the control algorithms on a full scale crane are considered. In the cargo alignment system a linear cascade controller is considered that is shown to have near time-optimal performance for a system with saturation in both the angle and the angular rate of the power swivel. In the second part a weakly coupled pair of state feedback controllers with a nonlinear compensator is used to eliminate the load oscillations in two dimensions. In the third part of the thesis a software tool for simulation and real time control is presented. The development of the program started as a spin-off to the crane projects.Godkänd; 1993; 20070417 (tgu)
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Hart, G. "Enhancing convective heat transfer in rotary kilns." Thesis, University of Surrey, 1985. http://epubs.surrey.ac.uk/842753/.
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The Fuels and Energy Research Group at the university of Surrey (FERGUS) have been investigating the heat transfer and energy utilisation within rotary cement kilns since the early 1970's. One such project has been the study of chain systems in cement kilns. The work presented in this thesis is an investigation of a chain system for dry process cement kilns. A review of the literature has highlighted that there is a general paucity of experimental work on cement kilns, and in particular, very little on the role of chain systems. This lack of applicable results is due to the fact that experimentation on this type of full-sized plant is exceedingly difficult. In modelling the convective heat transfer in a chained dry process cement kiln the analysis of Gardeik and Jeschar (1979) has been applied. These authors have developed an expression which enables the regenerative nature of a chained rotary kiln wall to be quantified. The similarity criteria utilised to scale down a chain system is that of equal voidages between the model chainbank and its industrial counterpart. This modelling criteria was developed by Patterson (1980) through air and water modelling experiments on different chain systems. In order to generate the basic heat transfer data a 1/8th scale, indirect fired, model of the chained section of Chinnor No. 1 Kiln of the Rugby Portland cement p.l.c. has been constructed. Clean low momentum flue gas from a vortex combustor has been used to heat, countercurrently, raw meal cement nodules for a range of gas and solid flowrates at different kiln rotational speeds. As with most experimental rotary kilns working at elevated temperatures (400ºC) many difficulties have had to be overcome, with a consequent alterations to the original design. The problem of continuous monitoring of temperature within the model kiln has been solved by the use of a programmable data recorder and a gold slip ring assembly external to the kiln. This system has simplified the acquisition, storage and retrieval of temperature data from a rotating kiln. Experiments have been performed with the model kiln operating without and with a chain system to quantify the swirl produced by the combustor and the regenerative action of the chainbank, respectively. The direct heat transfer coefficients between gas and wall have been determined as well as the overall heat transfer coefficient. Correlations of the data have been presented and where possible the results have been compared with the literature and to commonly used equations. For the model kiln operating with a chain system the gas to wall heat transfer has been correlated to yield: NU = 0.00661 Re1.15 Pr.33 and the overall heat transfer coefficient by: Keff = 0.002188 Re1.28 Significant enhancement in heat transfer to, a moving bed of solids has been achieved by using swirling flows in tandem with a chain system.
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Alyaser, Abdelmonem H. "Fluid flow and combustion in rotary kilns." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0013/NQ34505.pdf.
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Langrish, Timothy Alan Granville. "The mathematical modelling of cascading rotary dryers." Thesis, University of Oxford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330063.
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Macphee, James. "CFD Modelling of a Rotary Lime Kiln." Thesis, University of Canterbury. Mechanical Engineering, 2010. http://hdl.handle.net/10092/5186.
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McDonalds Lime Ltd, situated in Otorohanga, New Zealand, operate two dry process rotary lime kilns producing burnt and hydrated lime for a range of industries including agriculture, roading, water treatment, gold mining and steel making. The following Technology in Industry Fellowship (TIF) funded Masters Project is structured around investigating the combustion characteristics of Kiln Two at McDonald’s Lime Ltd using Computational Fluid Dynamics (CFD).
Numerical results obtained using the commercial CFD code FLUENT were first validated against experimental data from the International Flame Research Foundation’s (IFRF) Furnace No.1. The validation study focussed on comparing the finite rate and mixture fraction/PDF approaches to combustion chemistry, as well as different methods for defining coal particle size distributions.
Numerical modelling of Kiln Two at McDonald’s Lime Ltd began with full three-dimensional simulations, however due to their complexity and large computational times, two-dimensional axisymmetric models were primarily used for investigations. Comparisons were made between the two approaches. Investigations into the original pulverised coal fired system focussed on how the kiln aerodynamics and heat transfer properties were affected by changes to the coal and air inlet properties. The performance of a recently installed waste oil firing system was also investigated, with results showing that firing the kiln with a 25% thermal substitution of oil is the most efficient mode of operation. As the investigations focussed on the combustion characteristics the effects of the reacting limestone bed were ignored in all simulations.
CFD modelling of the combustion characteristics within a large scale rotary kiln proved to be an extremely complex task. The work presented in this thesis has however provided some promising results which will ultimately assist McDonalds Lime Ltd in reducing their operating costs and environmental impact. Futhermore, the project has laid the foundation for further investigations.
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Wallis, C. "The ozone disinfection performance of rotary contactors." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315668.
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DRUMOND, CARLO CESAR. "NUMERICAL SIMULATION OF A ROTARY STIRLING ENGINE." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=30089@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE EXCELENCIA ACADEMICA
O presente trabalho estuda um motor de deslocamento positivo Stirling rotativo. Dois modelos de simulação para este motor Stirling rotativo são desenvolvidos. O primeiro modelo utiliza o método isotérmico, mediante o qual a câmara de expansão/compressão do motor está à mesma temperatura do reservatório térmico com que troca calor. O segundo modelo utiliza o método de volumes de controle, no qual o motor é dividido em cinco volumes de controle: as câmaras de expansão e compressão, o aquecedor, o resfriador e o compartimento rotativo. Para cada volume de controle aplicam-se as equações de conservação de massa e energia e de equações de estado do gás. O sistema de equações diferenciais ordinárias resultantes do segundo modelo, é integrado, permitindo obter-se a variação no ângulo do eixo para todas as variáveis termodinâmicas do motor (pressão, temperatura, etc.). Dadas as condições de operação e a geometria do motor rotativo em estudo, os modelos preveem resultados globais e transientes ângulo a ângulo. Os resultados dos modelos são confrontados com resultados teóricos disponíveis na literatura.
The present work studies a positive displacement rotary Stirling engine. Two simulation models for this rotary Stirling engine are developed. The first model applies the isothermal method, in which the gas at the engine expansion / compression chamber has the same temperatures of the thermal reservoir. The second model uses the control volume method, in which the engine is divided into five control volumes: the expansion and compression chambers, the heater, the chiller and the rotary chamber. For each control volume the equations of conservation of mass and energy and the equation of state, are applied. The system of ordinary differential equations resulting from the second model is integrated allowing to obtain the variation in the axis angle for all thermodynamic variables of the motor (pressure, temperature, etc.). Given the operating conditions and geometry of the rotating motor under study, the models provide global and transient results from angle to angle. Results from two models are confronted with theoretical results available in the literature.
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Liebman, Michael Kevin 1974. "Rotary-linear axes for high speed machining." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8218.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references (p. 353-358).
This thesis presents the design, analysis, fabrication, and control of a rotary-linear axis; this axis is a key subsystem for high speed, 5-axis machine tools intended for fabricating centimeter-scale parts. The rotary-linear axis is a cylinder driven independently in rotation and translation. This hybridization minimizes machine inertias and thereby maximizes accelerations allowing for the production of parts with complex surfaces rapidly and accurately. Such parts might include dental restorations, molds, dies, and turbine blades. The hybrid rotary and linear motion provides special challenges for precision actuation and sensing. Our prototype rotary-linear axis consists of a central shaft, 3/4 inch (1.91 cm) in diameter and 15 inches (38.10 cm) long, supported by two cylindrical air bearings. The axis has one inch (2.54 cm) of linear travel and unlimited rotary travel. Two frameless permanent magnet motors respectively provide up to 41 N continuous force and 0.45 N-m continuous torque. The rotary motor is composed of commercially available parts; the tubular linear motor is completely custom-built. The prototype axis achieves a linear acceleration of 3 g's and a rotary acceleration of 1,300 rad/s2. With higher power current amplifiers and reduced sensor inertia, we predict the axis could attain peak accelerations of 12 g's and 17,500 rad/s2 at low duty cycles. This thesis also examines several concepts for developing a precision rotary-linear sensor that can tolerate axial translation.
Our prototype rotary sensor uses two laser interferometers to measure the orientation of a slightly tilted mirror attached to the shaft. A third interferometer measures shaft translation. The rotary axis has a control bandwidth of 40 Hz; the linear axis has a bandwidth of 70 Hz. The rotary-linear axis has 2.5 nm rms linear positioning noise and 3.1 prad rms rotary positioning noise. This thesis presents one novel 5-axis machine topology which uses two rotary-linear axes. The first axis rotates and translates the part. The second axis carries the cutting tool and provides high speed spindle rotation as well as infeed along the axis of rotation. For use as a spindle, precision rotary sensing is not required, and a sensorless control scheme based on motor currents and voltages can be used.
by Michael Kevin Leibman.
Ph.D.
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Davis, Karen Ann 1979. "Investigation of reverse plumbing in rotary seals." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/89394.
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Tarraf, Danielle C. (Danielle Charles) 1974. "Design of an unloader for rotary compressors." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47905.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.Includes bibliographical references (p. 139).
The capacity of rolling piston type rotary compressors is typically varied by using variable speed motor drives. That entails the use of high cost electronics. This study explores an alternative means of achieving variable capacity while keeping motor speed constant, by lifting the vane intermittently. The new technique should deliver comparable system performance and efficiency at lower initial costs in order to be competitive. The thesis starts by analyzing the kinematics and dynamics of the vane motion using simplified working models of the system. Also, the interaction between the vane and the rolling piston is modeled, with focus on possible impact between the moving parts. Next, the functional requirements for a vane lifting mechanism are set. The details of the design are worked out, and a complete set of engineering drawings is fully developed. A prototype of the mechanism was constructed; a brief description of the process is given. The last part of the thesis presents the experimental work done to prove the success of the concept, to assess the mechanism, and to determine optimal operation modes. The prototype is shown to fulfill its goal of varying system capacity. The weaknesses of the design are pointed out. Some effort is made to single out the parameters that set optimal cycling times. The main findings of the experiments are presented in a brief conclusion. Recommendations are made for second generation mechanism designs and for developing criteria for cycle time optimization.
by Danielle C. Tarraf.
S.M.
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Vona, Marsette Arthur 1977. "Metrology techniques for compound rotary-linear motion." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86760.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.Includes bibliographical references (p. 143-147).
by Marsette Arthur Vona, III.
S.M.
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Majeed, Fesmi Abdul. "Analysis and control of rotary drilling rigs." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/12559.
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The objective of this research is to analyze and develop controller to minimize vibrations of the drill string in rotary drilling rigs. The rotary drilling process is affected by many vibrations which adversely affect the drilling efficiency. The vibrations are mainly classified into three: lateral, tosional and axial. Among the vibrations, lateral vibrations are the most destructive. The research conducted a detailed analysis on lateral vibrations. Bent drill string and unbalanced drill bit was found to be its major causes; and the resultant phenomenon was known as drill bit whirl. Practical demonstration and analysis of the bit whirl phenomenon was done by conducting experiments using an unbalanced drill bit model. Their controllability issues were also discussed and practical solutions suggested. Black box identification methods were applied to develop mathematical models for the system. Box Jenkins structure model was identified and validated by a twofold procedure. Accurate simulations results were obtained with a mere 0.05% residual. Studies revealed that the vibrations in rotary drilling were aggravated by two major causes: borehole friction and critical operation speeds. This research developed a self tuning adaptive controller which could effectively mitigate the vibration aggravating causes and improve overall drilling efficiency. On practical implementation, the controller automatically detected vibrations, mitigated the vibration aggravating causes, and resumed normal drilling operation in less than 10 seconds. The controller action was proven experimentally in two cases: (1) when affected by borehole friction and (2) in presence of an unbalanced drill bit. All the experiments and control techniques applied in this research are validated by experimental data. The prototype used in this research is also distinguished from the rest due to a universal joint, providing an additional two degrees of freedom. Thus, the laboratory set-up provided better dynamic analysis.
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DeFrancesco, Richard E. "19mm Rotary Digital Data and Instrumentation Recording." International Foundation for Telemetering, 1988. http://hdl.handle.net/10150/615050.
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International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, NevadaA new family of recording devices has emerged which are user-friendly, 19mm cartridgebased use a MIL-STD format, and are capable of high transfer rates for diverse applications.
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Bittencourt, Agueda Bernadete 1950. "Comunhão leiga : o Rotary Club no Brasil." [s.n.], 1991. http://repositorio.unicamp.br/jspui/handle/REPOSIP/252000.
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Orientador : Mauricio TragtenbergTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação
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Vigué-Camus, Agnès. "Un groupe critiqué : sociologie du Rotary-Club." Paris, EHESS, 1991. http://www.theses.fr/1991EHES0059.
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Le rotary-club, comme d'autres associations a un but humanitaire, celui de "servir" les desherites. Pourtant ce groupe est la plupart du temps assimile a une assemblee de notables qui se reunit pour traiter des affaires et organiser des banquets. On cherche ici a expliquer l'illegitimite du groupe qui n'est pas sans liaison avec son origine americaine. En decrivant la difference dans la maniere dont est defini le groupe et dont il fonctionne a l'interieur de chacun des espaces nationaux, on tente d'amorcer une reflexion sur la specifite du lien civique et des formes d'expression de la citoyennete dans les deux paysLIKE MANY OTHER ASSOCIATIONS, THE ROTARY CLUB HAS HUMANITARIAN GOALS : "SERVING" THE DEPRIVED. YET AS A GROUP THIS CLUB IS PRIMARILY SEEN AS AN ASSEMBLY OF NOTABLES WHO GET TOGETHER TO DO BUSINESS AND ORGANIZE BANQUETS. WE TRY TO EXPLAIN THE ILLEGITIMACY OF THIS GROUP, IN FRANCE IN TERMS OF ITS AMERICAN ORIGINS. DESCRIBING THE DIFFERENT WAYS THE GROUP IS DEFINED AND HOW IT FUNCTIONS within DIFFERENT NATIONAL CONTEXTS, WE WOULD LIKE TO PROVOKE THOUGHT ABOU THE SPECIFICITY OF CIVIC LINKS AND THE FORMS OF EXPRESSION OF CITIZENSHIP IN THE TWO COUNTRIES
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Wei, Wei. "Design of coupled rotary traveling-wave oscillators /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2008. http://uclibs.org/PID/11984.
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Carniel, Stefano. "Simulazione numerica del processo rotary friction welding." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2015. http://amslaurea.unibo.it/8585/.
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