Abstract: This paper presents the results of an experimental investigation into the application of inverter-based variable speed drives to positive displacement rotary compressors. Designs and implements a DSP-microprocessor based of an inverter drive for high-efficiency compressor used in air conditioner. We control the compressor with sine PWM and V/F scheme. Permanent magnet synchronous motor has potential for energy saving in general applications on compressor drives. Permanent magnet synchronous motor drives are used for applications like compressors¡Awhere high dynamic performance is not a demand¡Asimple V/F control strategies may be sufficient to obtain the required control performance. For energy saving to find the best control strategy for an inverter drive for high efficiency compressor used in air conditioner.

<p>Intensive competition on the global market puts great pressure on manufacturing companies to develop and produce products that meet requirements from customers and investors. One key factor in meeting these requirements is the efficiency of the product development and the production preparation process. Design automation is a powerful tool to increase efficiency in these two processes.</p><p>The benefits of automating the production preparation process are shortened led-time, improved product performance, and ultimately decreased cost. Further, automation is beneficial as it increases the ability to adapt products to new product specifications with production preparations done in few or in a single step. During the automation process, knowledge about the production preparation process is collected and stored in central systems, thus allowing full control over the design of production equipments.</p><p>Three main topics are addressed in this thesis: the flexibility of design automation systems, knowledge bases containing conflicting rules, and the automation of the finite element analysis process. These three topics are discussed in connection with the production preparation process of rotary draw bending.</p><p>One conclusion drawn from the research is that it is possible to apply the concept of design automation to the production preparation process at different levels of automation depending on characteristics of the implemented knowledge. In order to make design automation systems as flexible as possible, the concept of object orientation should be adapted when building the knowledge base and when building the products geometrical representations. It is possible to automate the process of setting up, running, and interpreting finite element analyses to a great extent and making the automated finite element analysis process a part of the global design automation system.</p>

Im Rahmen einer Literaturauswertung wurde erkannt, dass die in Bohrformeln genutzten Gesteinsparameter mit der Gesteinsdruckfestigkeit und mit der spezifischen Energie für die Gesteinszerstörung korreliert. Numerische Untersuchungen ergaben, dass die spezifische Energie für die Gesteinszerstörung mit einem Bohrzahn in der Größenordnung der Druckfestigkeit liegt. In einem Autoklaven wurden Einzelzahneindringversuche mit zwei Zahnformen in einem durchlässigen Sandstein und in einem dichten Granit bei verschiedenen Drücken durchgeführt. Die spezifische Energie ist für den Sandstein gleich der effektiven Druckfestigkeit. Bei Versuchen im Granit konnte festgestellt werden, dass die Korngröße zusammen mit der Zahngeometrie einen Einfluss auf die benötigte spezifische Energie zur Gesteinszerstörung hat. Die Eindringfestigkeit kann mit einer aus Literaturdaten ermittelten Korrelation mit der Gesteinsdruckfestigkeit berechnet werden. Ausgehend von diesen Erkenntnissen wurde für Rollenbohrwerkzeuge eine charakteristische Gleichung aufgestellt, die die Fähigkeit des Werkzeuges beschreibt, Gesteine durch eine mechanische Belastung zu zerstören. Mit dieser charakteristischen Gleichung und der Gesteinsdruckfestigkeit kann somit eine erreichbare Bohrgeschwindigkeit berechnet werden.

The technology that has emerged in commercial products requires rigorous analytical tools for effective design of such motors. A finite element analytical model was developed to examine the excitation of flexural plate wave travelling in a rotary piezoelectric ally actuated motor. The model uses annular finite elements that are applied to predict the excitation frequency and modal response of an annular stator. This model is being developed to enable the design of efficient ultrasonic motors and it incorporates the details of the stator which include the teeth, piezo-ceramic, stator geometry, etc.

Non-spherical particles are present all around us, in biological, industrial and environmental processes. Making predictions of their impact on us and systems in our vicinity can make life better for everyone here on earth. For example, the ash particles from a volcano eruption are non-spherical and their spreading in the atmosphere can hugely impact the air traffic, as was also proven in 2010. Furthermore, the orientation of the wood fibres in a paper sheet influences the final properties of the paper, and the cause of a specific fibre orientation can be traced back to the fluid flows during the manufacturing process of the paper. In this thesis, experimental and numerical work is presented with the goal to understand and utilize the behavior of elongated particles in fluid flows. Two different experimental setups are used. The first one, a turbulent half channel flow, aims at increasing the understanding of how particles with non-zero inertia behave in turbulence. The second setup is an attempt to design a flow field with the purpose to align nanofibrils and create high performance cellulose filaments. Experiments were performed in a turbulent half channel flow at different flow set- tings with dilute suspensions of cellulose acetate fibres having three different aspect ratios (length to width ratio). The two main results were firstly that the fibres agglom- erated in streamwise streaks, believed to be due to the turbulent velocity structures in the flow. Secondly, the orientation of the fibres was observed to be determined by the aspect ratio and the mean shear, not the turbulence. Short fibres were oriented in the spanwise direction while long fibres were oriented in the streamwise direction. In order to utilize the impressive properties (stiffness comparable to Kevlar) of the cellulose nanofibril in a macroscopic material, the alignment of the fibrils must be controlled. Here, a flow focusing device (resulting in an extensional flow), designed to align the fibrils, is used to create a cellulose filament with aligned fibrils. The principle is based on a separation of the alignment and the assembly of the fibrils, i.e. first align the fibrils and then lock the aligned structure. With this process, continuous filaments were created, with properties similar to that of the wood fibre at the same fibril alignment. However, the highest alignment (lowest angle) of the fibrils in a filament created was only 31o from the filament axis, and the next step is to increase the alignment. This thesis includes modeling of the alignment process with the Smoluchowski equation and a rotary diffusion. Finding a model that correctly describes the alignment process should in the end make it possible to create a filament with fully aligned fibrils. / <p>QC 20140908</p>

The thesis proposes an overall performance estimation procedure for a new turbo-rotary compound engine (TURC) and an associated novel thermodynamic cycle. In this engine, two or multiple spools are lined up in series within the engine. In the front spool, positive displacement rotary vane type turbines drive axial compressor the performance of which were estimated using stage stacking calculations. In the back spool, axial turbine stages drive positive displacement rotary vane type compressors, the performance of axial turbine was predicted by series matching of turbine stages. Two air streams feed separately the customary turbo components and the rotary vane components, respectively. Accordingly, the primary high mass flow through the axial compressors and turbines undergoes Bryton cycle, where as the secondary, low mass flow through the positive displacement rotary components is mainly undergoes Akmandor cycle, which is a novel thermodynamic cycle. The energy consumed internally by the engine is minimized because less input shaft power is needed for the rotary vane compressors and higher inlet temperatures and less cooling can be tolerated by the intermittent combustion rotary vane turbines. The result is a radical improvement in both efficiency and net power output. But this result can be estimated, since the novel engine is the combination of a high efficiency internal combustion engine and high performance gas turbine engine. Aerothermodynamics and spool matching calculations comparing a T56-A14 core with a TURC of similar size and compression ratio show that the new engine provides superior performance characteristics by increasing the net output work by 100% and decreasing the specific fuel consumption by 20%.

Voluntary service is experiencing transition. This transition is marked by social, symbolic and policy changes that have transformed the relationship between paid and unpaid work, and is reordering the connection between voluntary practice and professional expertise. Giddens (1998) identified this as the third way. Rose (2000) sees this transformation as a strategy embodying a tacit regime around the economic transactions that implicate the agent in self-governance based on normative moral possibilities, thus ordering the moral subject. Research has not yet established the fundamental elements of this transforming logic, or the mechanisms by which oppositions such as paid and unpaid are being resolved by voluntary organisations. The thesis argues that third way commentators’ view of the bureaucratic transformation of voluntary service that examines “historical and social conditions, professional strategies, and disciplinary stakes and constraints…” (Shusterman, 1999: 10) does not account for the nature of service, or the practice and logic of that service. Therefore this study interrogates the notion and logic of service for the nature of the discourse and experience of service at the time of the move toward the third way, the point that voluntary values and practices meeting economic action. This logic is examined and extrapolated by empirical examination of the case service in Rotary and Zonta, organisations whose members are professional and act in voluntary positions. Bourdieu’s (for example 1984[1979], 1998, 2002[1977]) work on the logic of practice (featuring field, habitus and practice) frames the theoretical exploration of the embeddedness and logic of a particular social object in the context of practice. Exploring the field, habitus and practice for aspects of service suggests a multidimensional approach that investigates the discourse, experience, dispositions and contextual practice of service. Thus the study of service is conducted by collecting data from codes of professional conduct and objectives of Rotary and Zonta (the discursive level of interpretation); professionals’ experience and interpretation of volunteering (where the habitus of volunteers is made visible); and observations of practice and order at Rotary and Zonta meetings. The data was collected and analysed using Kenneth Burke’s rhetorical analysis (1969a, 1969b, 1989), Erving Goffman’s footing (Burns, 1992; Goffman, 1981), and Harvey Sacks’ indexicality and membership categorisation analysis (Lepper, 2000; Sacks, 2000[1992]). This study examines and reports on elements and relationships in the service discourse such as expertise, judgment and discretion; aspects of the logic of service exhibited in professional agent’s experience of voluntary service, including agency and professional ethics; and the rituals practiced by professionals in the voluntary context. Many of these elements are contextual components of the opposition between economic and symbolic values in the voluntary setting. Empirical evidence presented in this study suggests that voluntary service when practiced within the new frame of economic rationales and bureaucratic structures does not amalgamate opposing sectors so much as expose a common logic of service.

This thesis is a critical history of managerial and professional men in post-Second World War Australia. The attention that I have given managerial and professional men has been determined by my own political desire to problematise the continued accomplishment of hegemony. As subjects, these men and their discursive practices enable scrutiny of the regenerative labour necessary to sustain power and necessary to realise the material results that accrue to those performing such work. My thesis examines the practices of particular groups of managerial and professional men within four discrete social settings or terrain during the post-war period. I interrogate the operations of managerial and professional men in personnel management (the terrain of work), in market research (the terrain of the market), in parenting and marriage guidance (the terrain of the family) and in the service club Rotary (the terrain of the civic). In each of these terrains I find managerial and professional men framing problems and enacting solutions. A process or intervention that makes natural the connections of interest (of advantage or disadvantage) being constantly recreated; an intervention that expresses a comfort with the mechanics and entailments of hegemony. To enable my critical history I apply, in each terrain, a framework comprising three core elements. I historicize the accomplishment of hegemony; testing the emergence of government and positive expressions of power during post-war modernisation in the local contexts of managerial and professional men�s interventions. I people hegemony; identifying the practices of managerial and professional men as resources for doing social relations (in particular the relations of gender and class) and crucial to the operation of hegemony. And, thirdly, I demonstrate the interventions of these men to be interested; unravelling the possessive investments managerial and professional men make through their interventions. My scrutiny of managerial and profession men and their practices, my choice of terrains in which to study them, my analysis of the process enacted in these terrain and the sources that I have utilised are not intended to assemble a biography of men�s experiences or ideal masculinities. Rather, my thesis provides a biography of interventions in order to disassemble that which appears not to be anything in particular: the ordinary regeneration of hegemony by ordinary men doing ordinary things.

Diss. Linköping : Linköpings universitet, 2007.

Thesis (MScEng)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: This project concerns motion planning for a rotary wing UAV, where vehicle controllers are already in place, and map data is readily available to a collision detection module. In broad terms, the goal of the motion planning algorithm is to provide a safe (i.e. obstacle free) flight path between an initial- and goal waypoint. This project looks at two specific motion planning algorithms, the Rapidly Exploring Random Tree (or RRT*), and the Probabilistic Roadmap Method (or PRM). The primary focus of this project is learning how these algorithms behave in specific environments and an in depth analysis is done on their differences. A secondary focus is the execution of planned paths via a Simulink simulation and lastly, this project also looks at the effect of path replanning. The work done in this project enables a rotary wing UAV to autonomously navigate an uncertain, dynamic and cluttered environment. The work also provides insight into the choice of an algorithm for a given environment: knowing which algorithm performs better can save valuable processing time and will make the entire system more responsive. / AFRIKAANSE OPSOMMING: ’n Tipiese vliegstuuroutomaat is daartoe in staat om ’n onbemande lugvaartvoertuig (UAV) so te stuur dat ’n stel gedefinieerde punte gevolg word. Die punte moet egter vooraf beplan word, en indien enige verandering nodig is (bv. as gevolg van veranderinge in die omgewing) is dit nodig dat ’n menslike operateur betrokke moet raak. Vir voertuie om ten volle outonoom te kan navigeer, moet die voertuig in staat wees om te kan reageer op veranderende situasies. Vir hierdie doel word kinodinamiese beplanningsalgoritmes en konflikdeteksiemetodes gebruik. Hierdie projek behels kinodinamiese beplanningsalgoritmes vir ’n onbemande helikopter, waar die beheerders vir die voertuig reeds in plek is, en omgewingsdata beskikbaar is vir ’n konflikdeteksie-module. In breë terme is die doel van die kinodinamiese beplanningsalgoritme om ’n veilige (d.w.s ’n konflikvrye) vlugpad tussen ’n begin- en eindpunt te vind. Hierdie projek kyk na twee spesifieke kinodinamiese beplanningsalgoritmes, die “Rapidly exploring Random Tree*” (of RRT*), en die “Probabilistic Roadmap Method” (of PRM). Die primêre fokus van hierdie projek is om die gedrag van hierdie algoritmes in spesifieke omgewings te analiseer en ’n volledige analise te doen op hul verskille. ’n Sekondêre fokus is die uitvoering van ’n beplande vlugpad d.m.v ’n Simulink-simulasie, en laastens kyk hierdie projek ook na die effek van padherbeplanning. Die werk wat gedoen is in hierdie projek stel ’n onbemande helikopter in staat om outonoom te navigeer in ’n onsekere, dinamiese en besige omgewing. Die werk bied ook insig in die keuse van ’n algoritme vir ’n gegewe omgewing: om te weet watter algoritme beter uitvoertye het kan waardevolle verwerkingstyd bespaar, en verseker dat die hele stelsel vinniger kan reageer.