888 research outputs found

    Research on Parametric Model for Surface Processing Prediction of Aero-Engine Blades

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    This paper presented a method for establishing a blade surface machining prediction model based on a parametric model. The abrasive grain state of the grinding tool was divided into initial wear stage, stable wear stage and sharp wear stage. Based on this, a parametric prediction model of engine blade surface material removal was established. In this paper, the simulation of blade surface machining was carried out. In this work, the blade was divided into several sections according to the direction from the blade root to the blade tip. A certain curve of the outer contour was fitted with a specific arc to reduce the calculation amount. Through a series of simulation calculations, the expressions of the above parametric prediction model were obtained, and several experiments were carried out to verify the feasibility of the prediction model, and the results were analyzed

    Aeronautical Engineering: A special bibliography, supplement 60

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    This bibliography lists 284 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1975

    Aeronautical Engineering: A special bibliography with indexes, supplement 48

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    This special bibliography lists 291 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1974

    Aeronautical Engineering: A special bibliography with indexes, supplement 54

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    This bibliography lists 316 reports, articles, and other documents introduced into the NASA scientific and technical information system in January 1975

    Aeronautical engineering: A continuing bibliography with indexes (supplement 202)

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    This bibliography lists 447 reports, articles and other documents introduced into the NASA scientific and technical information system in June 1986

    Aeronautical engineering: A continuing bibliography with indexes, supplement 139

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    This bibliography lists 381 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1981

    Mission oriented R and D and the advancement of technology: The impact of NASA contributions, volume 2

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    NASA contributions to the advancement of major developments in twelve selected fields of technology are presented. The twelve fields of technology discussed are: (1) cryogenics, (2) electrochemical energy conversion and storage, (3) high-temperature ceramics, (4) high-temperature metals (5) integrated circuits, (6) internal gas dynamics (7) materials machining and forming, (8) materials joining, (9) microwave systems, (10) nondestructive testing, (11) simulation, and (12) telemetry. These field were selected on the basis of both NASA and nonaerospace interest and activity

    Development of a Software Tool to Estimate Airfoil Feature Variations

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    The objective of this thesis is to design and develop a software tool that analyzes the incoming raw material inspection data obtained from a Coordinate Measuring Machine (CMM) and estimates feature variation created within the manufacturing process i.e. from the raw material stage to finished stage. This tool is used not only to disposition whether a lot is conforming or non-conforming, but also to provide the root installation operators an ideal N-angle, Leading Edge Angle (LEA) and Trailing Edge Angle (TEA) target that maximize the yield of the lot after further processing. The tool also helps reduce the number of airfoil sections which need to be inspected both at In-Process and Final CMM inspection stages, thereby saving a considerable amount of inspection time as well as providing estimated cost savings of over a million dollars a year to the business

    Optimum Flash-Less Cold Forging Process For AUV Propeller Fabrication With FEM

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    The selection of the manufacturing process, flash-less cold forging die design and optimization of work-piece are the major issues to reduce the overall cost of the propeller. Substantial investigations have been carried out on this area, by many researchers using various tools and techniques. However, cold forging of complex geometries such as propeller hub and blade is still lacking. Moreover, volumetric analysis and optimization of work-piece have not been reported so far for complex geometries. In this thesis, the cold forging process has been adopted to produce the propeller hub and blade

    Computer-aided analysis and design of the shape rolling process for producing turbine engine airfoils

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    Mild steel (AISI 1018) was selected as model cold rolling material and Ti-6A1-4V and Inconel 718 were selected as typical hot rolling and cold rolling alloys, respectively. The flow stress and workability of these alloys were characterized and friction factor at the roll/workpiece interface was determined at their respective working conditions by conducting ring tests. Computer-aided mathematical models for predicting metal flow and stresses, and for simulating the shape rolling process were developed. These models utilized the upper bound and the slab methods of analysis, and were capable of predicting the lateral spread, roll separating force, roll torque, and local stresses, strains and strain rates. This computer-aided design system was also capable of simulating the actual rolling process, and thereby designing the roll pass schedule in rolling of an airfoil or a similar shape
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