The goal of this thesis work has been to develop and manufacture an ice layer which was to be mounted on the tip of a scaled down wing model. The iced wing should be tested in a wind tunnel and aerodynamic comparisons should be made to the same wing without ice.The development of the ice was carried out as a modified product development process. The main differences are that there is no costumer and that the actual shape and functions of the product are more or less predetermined. The challenge was to find the best way to create the ice layer and how to mount it to the wing without damaging it or covering any pressure sensors. Product development methods such as pros and cons lists and prototypes were used to solve problems before printing the plastic ice layer in a rapid prototyping machine.Wind tunnel experiments were then conducted on the wing with and without the manufactured ice. Raw data from the wind tunnel were processed and lift and drag coefficients were calculated using mathematical equations. Finally, conclusions were drawn by comparing the results from the wind tunnel tests with theory, other works as well as CFD simulations.The ice layer was successfully manufactured and it met the target specifications. The aerodynamic performance of an iced aircraft wing proved to be considerably worse compared to a blank wing. The maximum achievable lift force decreased by 22% and an increased drag force will require more thrust from the airplane.
The thesis is performed at GKN Aerospace Sweden AB in Trollhättan. During the thesis a value stream mapping is performed at a value stream performing maintenance of engine components in the flight industry. After the value stream mapping several suggestions were presented to streamline the value stream. The thesis is also meant to be a starting point for future evaluations when working with improvements for flexible value streams.
The component whose value stream has been evaluated is called 30k Compressor Intermediate Case. The value stream varies and different operations can be performed depending on what the customer orders. Due to the variation the lead time can be different from components in the value stream. The thesis focused on evaluating processes that occur regularly when 30k Compressor Intermediate Case components arrive at GKN. Other components that use the same processes have not been evaluated.
A value stream mapping is a tool to visualize a value stream. A visualization of the stream will show how the value stream is built and the lead time can clearly be shown for the component. Deviant key figures can be evaluated to gather an understanding of where focus should be placed when working with improvements.
Information has been gathered through interviews, observation and collected data from the company's databases. This was compiled to a description of the current value stream which was visualized. The gathered information was used to create a picture of the value stream to examine what processes that's regularly performed. The observations were performed to evaluate how the operators work within the processes which created an understanding of what happens. The information was concluded in a current state analysis which shows how the value stream is built. The suggestions of improvement were presented in a bulleted list after an evaluation of the current value stream.
The result from the value stream mapping shows that there is a variety in queue time in the range of low to high ahead of the processes. The capacity of the blaster, varnishing and the arrival control is one at the time. An increased capacity would enable more details to undergo the processes at the same time. Waste has also been identified in the arrival inspection where operators move unnecessary distances to collect documents from a printer and to throw away debris arriving with the components packaging. Within the value stream the components are transported with a manually pushed cart that is rebuilt for other components from other value streams. This brings an adjustment time to the arrival inspection. In the analysis the authors suggest using component specific carts. During the blaster an observation was made of more masking than necessary which should be minimized. The result also shows that a standard should be set of how time reporting should be made by the company's guidelines.
The report shows how a value stream mapping created a clear overview of value streams where bottlenecks can be identified. When eliminating bottlenecks it's important to not create another bottleneck in another process but to eliminate it entirely from the value stream. A value stream mapping is an efficient tool to map processes and their times which in the conclusion is described as a good methodology to streamline value streams.
The aerospace industry is increasingly using the Additive Manufacturing (AM) to produce Nickel-based superalloy components with complex geometries. The use of this manufacturing technology is particularly focused on the development of hot-section components for gas turbine engines, which require increased efficiency. An increase in their operating temperatures could be achieved by developing cooling channels components using AM processes such as Electron Beam – Powder Bed Fusion (EB-PBF) and protecting them with Thermal Barrier Coatings (TBCs). Thermal Barrier Coatings have been used for several decades in the gas turbine industry to protect conventionally manufactured components from the high-temperature environment. The objective of this work is to evaluate the surface, the microstructure, and the functional properties of TBCs deposited on EB-PBF additive manufactured substrates.
In this study, Thermal Barrier Coatings were sprayed onto HAYNES®282® superalloy AM substrates manufactured by the EB-PBF process. For reference, Thermal Barrier Coatings sprayed onto HAYNES®282® forged substrates have also been prepared. The TBC bondcoats were sprayed by the High Velocity Air-Fuel (HVAF) process using NiCoCrAlY powder feedstock. Seven different spray runs were performed to deposit the TBC top-coats by the Suspension Plasma Spraying (SPS) process using different parameters and two different suspensions of 8wt.% Yttria-Stabilized Zirconia (8YSZ). Characterizations were then carried out on the samples.
The results obtained showed that the deposition of the bond-coats reduces the roughness and asperities of the AM substrates caused by the EB-PBF manufacturing method. The Thermal Barrier Coatings exhibit vertically cracked and columnar microstructures depending on the suspensions and spray parameters used. The TCF lifetimes obtained for the Thermal Barrier Coatings on the AM substrates were not lower than those achieved for the Thermal Barrier Coatings on the standard substrates. The deposition of Thermal Barrier Coatings on substrates made by Additive Manufacturing process results in microstructures similar to what could be obtained on conventional substrates.
Weld inspection for surface breaking defects detection has been traditionally performed by using NDT methods such as Fluorescent PenetrantInspection (FPI), Visual Inspection (VI) or Eddy Currents (EC). All those well known techniques have as common drawback the need of skilled operator intervention in order to analyse obtained results. In the specific case of inspection of welds with limited access, the application of those traditional methods is even more complex, thus increasing inspection time and reducing the defect detection capability. Therefore, the development of a fully automated non-contact method overcoming these limitations is desired. Active thermography (IRT) represents one of the most promising techniques for replacing traditional techniques for surface breaking defect detection in welds.This technique makes use of an excitation source in order to heat the sample undertest and an infrared camera for thermal evolution monitoring. With the combination of these excitation-monitoring techniques, heterogeneities in the heat flow caused bysurface breaking cracks can be detected. In this work, a robotic solution was developed and demonstrated for the inspection of welds with real cracks in a representative environment with limited access. The system consists of a continuous laser-line excitation source together with a FLIR SC 655 micro bolometer thermographic camera. In order to access limited areas, two different aluminium polished mirrors have been used for bothinfrared radiation monitoring and laser excitation respectively. The inspection results, analysis and comparison with traditional methods will be shown.
Fundamental understanding of relationships between coating microstructure and thermal conductivity is important to be able to understand the influence of coating defects, such as delaminations and pores, on heat insulation in thermal barrier coatings (TBC). Object Oriented Finite element analysis (OOF) has recently been shown as an effective tool for evaluating thermo-mechanical material behaviour as this method is capable of incorporating the inherent material microstructure as an input to the model. The objective of this work was to evaluate a procedure where this technique is combined with Tbctool, a plasma-sprayed TBC like morphology generator, thus enabling development of low thermal conductivity coatings by simulation. Input parameters for Tbctool were computed from SEM images of sprayed microstructures using the image analysis software, Aphelion. Microstructures for as-sprayed as well as heat treated samples were evaluated. The thermal conductivities of the artificially generated microstructures were determined using OOF. Verification of the modelling procedure was performed by comparing predicted values by OOF with corresponding measured values using the laser flash technique. The results, although tentative in nature, indicate that the proposed simulation approach can be a powerful tool in the development of new low conductivity coatings.
This paper presents the benefits and challenges ofusing a standard robotised laser welding cell for additive manufacturing(AM). Additive manufacturing, sometimes denoted3D-printing or rapid prototyping, has lately met strong interestin several areas of society, and a variety of technologies andmaterials have been in focus. The current paper summarisesautomation efforts for AM of advanced aero engine componentsusing high power laser with welding optics as power source formelting metal wire and using an industrial robot for obtaininga 3-dimensional feature shape. The challenges are related to theprocess itself encountering high and repeated temperatures withmelting and solidification of the metal as the main players. Themajor research solutions discussed in this paper are relatedto automation issues for obtaining a stable process and tohave control of the temperatures and temperature changes thatthe metals encounter during the process. The solutions aresuccessfully implemented in an industrial laser welding cell.
Att de flygplan som används i flygtrafiken är oskadade är självklart en viktig förutsättning för flygsäkerheten. När flygplanen befinner sig på mark sker en mängd olika operativa moment i och omkring planen, ofta under tidspress, och som involverar ett stort antal individer, organisationer, och olika typer av teknisk apparatur. För att flygplanen inte ska komma till skada i dessa operationer måste de utföras enligt tydliga procedurer, med kunskap och noggrannhet och med hög grad av koordinering av olika moment och aktörer. Detta ställer höga krav på de formella säkerhetssystemen. Men flygsäkerheten påverkas även av individuella och sociala fenomen. De sociala förutsättningarna handlar om hur sociala normer ser ut och utvecklas på arbetsplatsen. Här blir fenomen som säkerhetskultur och säkerhetsklimat betydelsefulla. En förutsättning för att kunna arbeta med att utveckla flygsäkerhetsklimatet så att det än bättre stöder en hög flygsäkerhet vid flygplatsarbetet är att man kan skaffa sig en uppfattning om kvaliteten på säkerhetsklimatet. Är det högt eller lågt? Vilka är de svaga punkterna, som behöver åtgärdas? Och vilka är de starka sidorna, som man bör gynna ytterligare? Ett sätt att mäta säkerhetsklimatet är genom enkät. Denna delrapport ger en teoretisk bakgrund till begreppet säkerhetsklimat och beskriver sedan utvecklingen av ett enkätinstrument för att mäta flygsäkerhetsklimat vid flygplatsarbete; Airdrome Aviation Safety Climate Questionnaire, ADASCQ.
In this contribution, it is shown how multivariable sampled-data controllers can be generated for a set of linearized models. The size of this set makes an automatic generation of controllers more practical and less time consuming. The control strategy is robust loopshaping according to Glover/McFarlane. The generated controllers are to be used for the military turbofan engine F404-RM12 which is currently used in the Swedish air fighter JAS39 Gripen.