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The effects of trailing edge flow control on the wakes of a linear cascade of idealized fan blades was investigated experiments with a view to the likely effects on broadband aircraft engine interaction noise. Single and three-component hotwire velocity measurements were made downstream of the cascade for a chord Reynolds number of 390,000 and a Mach number of 0.07. Measurements of the two-point velocity correlation were used extensively to evaluate the impact of various flow control strategies on the organization of the coherent structures of the wakes and their potential to generate noise. A baseline flow was established by measuring the wake downstream of unmodified GE-Rotor-B blades. Four sets of serrated trailing edge blades (with two different serration sizes and with two trailing edge cambers) and three sets of blades with trailing edge blowing (a simple rectangular slot, rectangular slot with Kuethe-vane vortex generators, and rectangular slot with serrated lips) were tested. The serrated trailing edges introduce corrugations into the wake, increase the wake decay and width as well as turbulence levels (possibly because of the blunt trailing edge created at the serration valley). The serrated trailing edges also increase the turbulence scales in the direction perpendicular to the plane of the wake because of the injection of streamwise vorticity. In almost all cases the serrations reduce the spanwise and streamwise turbulence scales. Serrations do not, however, affect the apparent time scale of quasi-periodic structures in the wake, and this appears to limit the potential of this trailing edge treatment to reduce broadband noise. The analysis of the characteristic eddies (obtained from proper orthogonal decomposition combined with linear estimation) revealed that the serrations do not change the qualitative form of the eddies. Trailing edge blowing was found to significantly decrease the wake deficit and width as well as the turbulence levels at all blowing rates. Blowing through the simple rectangular slot, at mass flow rates between 1.4 and 2.0% of the total passage through flow, was shown to significantly affect the size, the organization and the strength of the coherent structures. For small blowing rates the strong spanwise eddies near the trailing edge actually appear to be enhanced. For larger blowing rates, however, the turbulent scales are reduced in all directions. The addition of Kuethe vanes on the suction side of the blowing blade results in a low momentum region just downstream of the vanes that may result from flow separation there. This further enhances the shedding and increases the blowing rate needed to overcome it. The serrated blowing blades show the greatest potential to reduce broadband noise as they reduce the turbulence levels and scales without creating potentially detrimental structures. While no acoustic measurements were made, analysis of hypothetical perpendicular and parallel interactions of blades with these wakes has made possible to characterize for the first time the impact of the changes in the eddy structure of these wakes on their potential to generate broadband noise. The serrated trailing edges (especially the larger serrations) actually increase the potential of the wake to generate broadband noise (a direct consequence in the overall increase in turbulence scale and intensity). In contrast, every trailing edge blowing configuration was found to produce large reductions in the potential noise (a maximum of 6dB reduction was obtained at 2.0% blowing). The addition of Kuethe vanes on the suction side of the blowing blades significantly reduced the efficiency of the simple blowing configuration (a result of the increased coherency associated with the shedding of streamwise vorticity by the vanes). The serrated blowing configuration was found to yield reductions similar to the simple blowing configuration. / Ph. D.

<p>Volvo Aeros flygmotortillverkning i Trollhättan har infört ett antal nya detaljvarianter i produktionen. Detta har medfört att den robotcell som är avsedd att utföra en avgradningsoperation är i behov av uppdatering av både hårdvara och mjukvara. Denna rapport följer framtagningen av fixturkoncept som möjliggör att robotcellen kan användas även till de nya detaljerna. De förslag som arbetats fram sträcker sig från enklast möjliga till mer avancerade och nytänkande funktioner. Samtliga funktioner och koncept har genomgått gallringar i ett flertal steg. Förslagen har slutligen kombinerats och poängbedömts med konceptgenereringsverktyg till grund.</p><p>Efter en objektiv poängbedömning av sex olika koncept baserad på concept scoring visar sig två huvudgrupper med tre koncept i varje. Den ena gruppen bygger på en mer avancerad konstruktion med behov av två rotationsaxlar. Dessa medför ett flertal fördelar gällande effektivitet, men även påtagliga nackdelar vad gäller ekonomiska aspekter och idrifttagandetid. Den andra gruppen av koncept baseras mer på det befintliga fixturkonceptet. Detta medför fördelar gällande idrifttagandetid och kostnader.</p><p>Ett huvudkoncept som efter poängbedömningen visat sig mest lämpligt presenteras mer ingående och slutligen förs en diskussion gällande resultatets utfall samt rekommendationer till fortsatt arbete.</p> / <p>Volvo Aero’s aircraft engine manufacturing in Trollhättan has introduced a number of detail models into the production. As a consequence the robot cell dedicated to executing a deburring operation is in need of upgrading of both hardware and software. This report follows the development of fixture concepts that enables the robot cell to be used also for the new details. The proposals that have been developed range from the simplest to more advanced including novel functions. All the functions and concepts have gone through selection in multiple steps. The suggestions have finally been combined and evaluated with concept generation tools.</p><p>After an objective selection based on the concept scoring of six different concepts, the result can be divided into two main groups, each consisting of three concepts. The first group is a more advanced design with a need of two axes of rotation. These three concepts have several advantages when it comes to efficiency, but also obvious disadvantages when it comes to economy and production time. The second group of concepts is based on the fixture existing today. These three concepts are advantageous concerning production time and cost.</p><p>After the scoring process one main concept, judged to be the most suitable is presented more thoroughly. Finally the results as well as recommendations for continued work are discussed.</p>

The content of customer-perceived value has in this study been explored with the aim of providing an understanding of the concept. The evolving service-centered logic for marketing puts an emphasis on value, especially the value perceived and determined by the customer. Concurrently, a development is recognized within the industrial business-to-business sector where goods and services are packaged into total service offerings – with an increasing prominence for services. This is the background of the study. The study itself was conducted in order to elucidate the concept of customer-perceived value in a context where total service offerings are provided within dyadic business-to-business relationships. The conceptual framework, guiding the empirical study, has its points of departure in the field of service research. A case study conducted in the commercial aircraft engine maintenance industry has provided a description – depicted in value maps – of context-specific attributes forming the dimensions of customer-perceived value. It is suggested that customer-perceived value is created at three levels; at a product level, at a partnership level, and at a psychological level. Furthermore, the value maps clarify the double nature of customer-perceived value, which is found to have both an origin side – how the service provider should act to deliver value – and a side illuminating the more or less monetarily quantifiable effects of value. The origin and effect of customer-perceived value are proposed to be explained by a model where the notion of “flow” is central. Flows of goods, information, risk, involvement, and money intersect the value features and provide the sources of value on the origin side of customer-perceived value. The effects can be traced to the flows of revenue benefits, cost benefits, interest effects, and costs to use. Concurrently, flows both build, and are filtrated by, “trust” during the process in which the customer’s perception of value comes into being. On the effect-side of value, the concepts stochasticity and substantiality are introduced in order to capture the uncertainties that make translations into monetary terms difficult. The outcome of the abductive reasoning in the final phase of the investigation is a conceptual model – proposed as the main contribution of the study – summarizing aspects of customer-perceived value. My definition of customer-perceived value, together with a list clarifying the many facets of the concept, concludes the study.

Volvo Aeros flygmotortillverkning i Trollhättan har infört ett antal nya detaljvarianter i produktionen. Detta har medfört att den robotcell som är avsedd att utföra en avgradningsoperation är i behov av uppdatering av både hårdvara och mjukvara. Denna rapport följer framtagningen av fixturkoncept som möjliggör att robotcellen kan användas även till de nya detaljerna. De förslag som arbetats fram sträcker sig från enklast möjliga till mer avancerade och nytänkande funktioner. Samtliga funktioner och koncept har genomgått gallringar i ett flertal steg. Förslagen har slutligen kombinerats och poängbedömts med konceptgenereringsverktyg till grund. Efter en objektiv poängbedömning av sex olika koncept baserad på concept scoring visar sig två huvudgrupper med tre koncept i varje. Den ena gruppen bygger på en mer avancerad konstruktion med behov av två rotationsaxlar. Dessa medför ett flertal fördelar gällande effektivitet, men även påtagliga nackdelar vad gäller ekonomiska aspekter och idrifttagandetid. Den andra gruppen av koncept baseras mer på det befintliga fixturkonceptet. Detta medför fördelar gällande idrifttagandetid och kostnader. Ett huvudkoncept som efter poängbedömningen visat sig mest lämpligt presenteras mer ingående och slutligen förs en diskussion gällande resultatets utfall samt rekommendationer till fortsatt arbete. / Volvo Aero’s aircraft engine manufacturing in Trollhättan has introduced a number of detail models into the production. As a consequence the robot cell dedicated to executing a deburring operation is in need of upgrading of both hardware and software. This report follows the development of fixture concepts that enables the robot cell to be used also for the new details. The proposals that have been developed range from the simplest to more advanced including novel functions. All the functions and concepts have gone through selection in multiple steps. The suggestions have finally been combined and evaluated with concept generation tools. After an objective selection based on the concept scoring of six different concepts, the result can be divided into two main groups, each consisting of three concepts. The first group is a more advanced design with a need of two axes of rotation. These three concepts have several advantages when it comes to efficiency, but also obvious disadvantages when it comes to economy and production time. The second group of concepts is based on the fixture existing today. These three concepts are advantageous concerning production time and cost. After the scoring process one main concept, judged to be the most suitable is presented more thoroughly. Finally the results as well as recommendations for continued work are discussed.

This master’s thesis deals with creating a real-time simulation model of an aircraft piston engine with emphasis on heating and cooling of the engine cylinders. First part of this thesis focuses on characteristics of aircraft engines and differences with regular automotive engines. The next chapter describes the dependence of engine parameters on atmospheric conditions. The description of the real time model itself follows next. The results of the simulation model are presented and analysed at the end of this thesis.

Master’s thesis deals with comparsion and rating the compressed natural gas as an aircraft piston engine fuel. An information search of conventional fuels and differences of the fuel systems for AVGAS and CNG is included. Next part describes the aircraft and its engine on which is the mathematic model based. After that perfomance and consumption data are calculated for both fuels and the results are then compared. At the end of the thesis, a design of the CNG fuel system with components selection is described.

Configuration of the powertrain of a flat-eight engine with ordered basic parameters is the theme of this thesis which name is Powertrain design of an eight-cylinder aircraft engine. This thesis occupies with configuration design of the crank mechanism and firing order, balancing of centrifugal and reciprocating forces and their moments, conceptual design of crankshaft and its stress calculation. This thesis also puts mind to calculation of torsional vibrations.