The Experts below are selected from a list of 7182 Experts worldwide ranked by ideXlab platform
Denis Gusakov - One of the best experts on this subject based on the ideXlab platform.
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design of high temperature six phase starter generator embedded in Aerospace Engine
International Review of Aerospace Engineering, 2016Co-Authors: Flur Ismagilov, Vyacheslav Vavilov, Lubov E Roginskaya, Semen Shapiro, Denis GusakovAbstract:This paper examines the problem of the installation of the electric machine to the high pressure shaft to increase the electrification of aircraft Engines and create More Electrical Engine. Different ways of synchronous generator integration in the aircraft Engine by worldwide aircraft Engines manufacturers was discussed. A new design of the high temperature synchronous generator mounted on high pressure shaft is proposed. To evaluate the effectiveness of synchronous generator the electromagnetic, thermal and mechanical calculations are made. High temperature synchronous generator cooling system was designed and system of mechanical decoupling of the stator at short circuits is proposed.
Horacio Sorianomeier - One of the best experts on this subject based on the ideXlab platform.
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a dmairc approach to lead time reduction in an Aerospace Engine assembly process
Journal of Manufacturing Technology Management, 2014Co-Authors: Jose Arturo Garzareyes, Ashley Flint, Vikas Kumar, Jiju Antony, Horacio SorianomeierAbstract:Purpose – Problem solving and continuous process improvement are key elements to achieve business excellence. Many problem solving and process improvement methodologies have been proposed and adopted by organisations, with DMAIC being the most widely used. The purpose of this paper is to present an empirical application of a modified version of DMAIC which enabled a world-class organisation to achieve an optimum reduction in the lead time of its Aerospace Engine assembly process. Design/methodology/approach – The paper reviews the most commonly used problem solving and process improvement methodologies and specifically, DMAIC, its variations and limitations. Based on this, it presents define, measure, analyse, improve, review, control (DMAIRC). Finally, DMAIRC is empirically applied through a case study, in a world-class manufacturing organisation. Findings – The results obtained from the case study indicate that DMAIRC is an effective alternative to achieve the maximum improvement potential of a process....
Bikiran Goswami - One of the best experts on this subject based on the ideXlab platform.
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Applications of thermal barrier coating system in gas turbines - A review
2004Co-Authors: A. K. Ray, Bikiran GoswamiAbstract:Ceramic coatings are refractory metal oxides deposited on substrate to reduce thermal loss and to protect components, being operuted at high temperature. Thermal barrier coatings (TBC) are composite overlay of bond coat and ceramic coat on a superallor substrate implemented in combustion Engines. Thermal and mechanical strains of service exposure requires structural compliance tolerances. This is facilitated by brittle constituent deposition technique over a ductile substrate. Electron beamphysical vapour deposition and plasma spray technique provides this from tortuous intergrunular network of coating. Porous deposition technique is applied in most cases instead of cementation or continuous section thickness. Thermal barrier coating is inevitable in Aerospace Engine sections operating at limiting conditions of strains. This is attributed to reduction of temperature levels and grat1iets.Subsequent advantages are protection of high temperature components for maximum utilisation of component lives and maximum utilisation of energy by operating at optimum allowable temperature limits. Thermo-mechanical behaviour of TBC is optimised by ill-situ formation and transformation mechanisms of alumina from aluminium of substrate/bond coat and metastable tetragonal zirconia to stable tetmgonal zirconia respectively at temperature of service. The former produces a volumetric contraction whereas later produces volumetric expansion. In service the composite system provides an auto-toughening effects in due courses. Mechanical behaviour of TBC is attributed to the intergranular tortuous network. This on strain exposure form cracks and at the second stage of crack tip blunting form cubic allotropy from metastable tetragonal phase. Reduction of cia ratio thus increases toughness. However a prolonged exposure form localised spallation zones being initiated by volumetric expansion stresses associated with nickel enrichment of thermally grown oxides (TBC) at bond coat/ceramic coat interface and auto-sintering. TBC interaction directly with substrate is a wide variation of ductility. So bond coat is applied to produce mechanical adherence and stress relaxation effects. Generally M-CrAIY family of bond coating alloys are used. Exposure to operatingltest temperature produces thermally grown oxides (TGO) at interface. This occupies an intermediate zone in response to property interactions. TGO mainly consists of alumina being catalysed by chromia and adhered by yttria. Current scenario is to study contmdiction between auto-sintering and auto-toughening mechanisms and to decrease effects of thermal expansion mismatch stresses by application of composite coatings made from functionally graded materials microlaminated,and multilayeredceramic/ceramicor metallic/ceramicor metallic/metallic coatings. Application of laser scaling or remelting to reduce porosity of free surface and to increase glaze is another avenues to reduce diffusion of reactive gases and to increase internal heat transfer respectively. The former state increases life of bond coat/substrate, where as later increase energy efficiency by maximu mutilisation of heat.The main unsolved problems are spallation of ceramic coating being cohesively induced in either side of interface and spread out to interfacesof adhesion. TBC increase life more than twice for cases of Aerospace Engines however localised spallation by high temperature corrosion of bond coat/substrate, TGO stresses, gaseous/liquid contaminant diffusion/impregnation through tolerance networking of voids. erosion and their addItive effects increase pressure over preventive measure.
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Thermal Barrier Coating System for Gas Turbine Application- A Review
High Temperature Materials and Processes, 2003Co-Authors: Bikiran Goswami, A. K. Ray, S K SahayAbstract:Ceramic coatings are refractory metal compounds deposited on substrates to reduce thermal loss and to protect components from high temperature. Thermal barrier coatings (TBC) are composite overlay of bond coat and ceramic coat on a superalloy substrate. Atomised deposition or splat deposition of fine semi-molten particle technique deposits thin coatings of brittle ceramic. Thermal and mechanical strains arising from service exposure require structural compliance tolerances. This is facilitated by brittle constituent deposition over a ductile substrate. Electron beam physical vapour deposition and plasma spray technique lead to a tortuous intergranular network of coating. Porous deposition technique is applied in all cases instead of cementation or continuous section thickness. Thermal barrier coating is inevitable in Aerospace Engine sections operating at limiting conditions of strains. Thermal barrier coatings help in protection of high temperature components for maximum utilisation of component lives, and maximum utilisation of energy by operating at optimum allowable temperature limits. Thermo mechanical behaviour of TBC is optimised by in-situ formation and transformation mechanisms of alumina from aluminium of substrate/bondcoat and metastable tetragonal zirconia to stable tetragonal zirconia respectively at temperature of service. While the former produces a volumetric contraction, the latter produces volumetric expansion. In service the composite system provides auto-toughening effects in due course. An intergranular tortuous network of coating forms cracks on exposure of strain and the crack tip blunting forms cubic allotropy from metastable tetragonal phase, resulting in an increase in toughness due to elimination of c/a ratio. However, a prolonged exposure forms localised spallation zones, which are initiated by volumetric expansion stresses associated with nickel enrichment of thermally grown oxides (TGO) at bond coat/ceramic coat interface, and auto-sintering. Bond coat is applied to produce mechanical adherence and stress relaxation effects. Generally M-CrAlY families of bond coating alloys are used for this purpose. Exposure to operating/test temperature produces thermally grown oxides (TGO) at interface. This occupies an intermediate zone in response to property interactions. TGO mainly consists of alumina being catalyzed by chromia and adhered by yttria. Active research is going on to study the mechanisms of auto sintering and auto-toughening of TBC. Work is in progress to explore how to decrease thermal expansion mismatch stresses by application of composite coatings made from functionally graded materials, microlaminated, and multilayered ceramic/ ceramic or metallic/ceramic or metallic/metallic coatings. The application of laser scaling or remelting to reduce porosity of free surface and to increase glaze are other avenues to reduce diffusion of reactive gases and to increase internal heat transfer respectively. The former increases life of bond coat/substrate, whereas the latter increases energy efficiency by maximum utilisation of heat. The main unsolved problem is spallation of ceramic coating, which is cohesively induced in either side of interface and spread out to interfaces of adhesion. TBC increases life more than two-fold for cases of Aerospace Engines. However localised spallation may rise by high temperature corrosion of bond coat/substrate, TGO stresses, gaseous/liquid contaminant diffusion/ impregnationthrough tolerance networking of voids, and erosion.
Hye Jung Chang - One of the best experts on this subject based on the ideXlab platform.
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dual phase high entropy alloys for high temperature structural applications
Journal of Alloys and Compounds, 2017Co-Authors: Ka Ram Lim, Kwang Seok Lee, Jun Seo Lee, Jinyeon Kim, Hye Jung ChangAbstract:Abstract The dual-phase AlCoCrFeNi alloy exhibits excellent specific strength in the 773–873 K temperature range. However, the phase transformation taking place above 773 K hinders its structural use at higher temperatures. In the present study, the temperature dependence of the specific strength of the AlCoCrFeNi alloy has been examined from a microstructural point of view. One of the key findings of this work is that the high-temperature phase stability of the dual-phase alloy is strongly affected by its microstructural morphology; this finding provides new insights into the application of high-entropy alloys as high-temperature structural materials, for instance in Aerospace Engine components.
Jinyeon Kim - One of the best experts on this subject based on the ideXlab platform.
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dual phase high entropy alloys for high temperature structural applications
Journal of Alloys and Compounds, 2017Co-Authors: Ka Ram Lim, Kwang Seok Lee, Jun Seo Lee, Jinyeon Kim, Hye Jung ChangAbstract:Abstract The dual-phase AlCoCrFeNi alloy exhibits excellent specific strength in the 773–873 K temperature range. However, the phase transformation taking place above 773 K hinders its structural use at higher temperatures. In the present study, the temperature dependence of the specific strength of the AlCoCrFeNi alloy has been examined from a microstructural point of view. One of the key findings of this work is that the high-temperature phase stability of the dual-phase alloy is strongly affected by its microstructural morphology; this finding provides new insights into the application of high-entropy alloys as high-temperature structural materials, for instance in Aerospace Engine components.