Structural Material Property Tailoring Using Deep Neural Networks

Advances in robotics, artificial intelligence, and machine learning are ushering in a new age of automation, as machines match or outperform human performance. Machine intelligence can enable businesses to improve performance by reducing errors, improving sensitivity, quality and speed, and in some cases achieving outcomes that go beyond current resource capabilities. Relevant applications include new product architecture design, rapid material characterization, and life-cycle management tied with a digital strategy that will enable efficient development of products from cradle to grave. In addition, there are also challenges to overcome that must be addressed through a major, sustained research effort that is based solidly on both inferential and computational principles applied to design tailoring of functionally optimized structures. Current applications of structural materials in the aerospace industry demand the highest quality control of material microstructure, especially for advanced rotational turbomachinery in aircraft engines in order to have the best tailored material property. In this paper, deep convolutional neural networks were developed to accurately predict processing-structure-property relations from materials microstructures images, surpassing current best practices and modeling efforts. The models automatically learn critical features, without the need for manual specification and/or subjective and expensive image analysis. Further, in combination with generative deep learning models, a framework is proposed to enable rapid material design space exploration and property identification and optimization. The implementation must take account of real-time decision cycles and the trade-offs between speed and accuracy

Modeling Micro-Porous Surfaces for Secondary Electron Emission Control to Suppress Multipactor

This work seeks to understand how the topography of a surface can be engineered to control secondary electron emission (SEE) for multipactor suppression. Two unique, semi-empirical models for the secondary electron yield (SEY) of a micro-porous surface are derived and compared. The first model is based on a two-dimensional (2D) pore geometry. The second model is based on a three-dimensional (3D) pore geometry. The SEY of both models is shown to depend on two categories of surface parameters: chemistry and topography. An important parameter in these models is the probability of electron emissions to escape the surface pores. This probability is shown by both models to depend exclusively on the aspect ratio of the pore (the ratio of the pore height to the pore diameter). The increased accuracy of the 3D model (compared to the 2D model) results in lower electron escape probabilities with the greatest reductions occurring for aspect ratios less than two. In order to validate these models, a variety of micro-porous gold surfaces were designed and fabricated using photolithography and electroplating processes. The use of an additive metal-deposition process (instead of the more commonly used subtractive metal-etch process) provided geometrically ideal pores which were necessary to accurately assess the 2D and 3D models. Comparison of the experimentally measured SEY data with model predictions from both the 2D and 3D models illustrates the improved accuracy of the 3D model. For a micro-porous gold surface consisting of pores with aspect ratios of two and a 50% pore density, the 3D model predicts that the maximum total SEY will be one. This provides optimal engineered surface design objectives to pursue for multipactor suppression using gold surfaces

Addendum to type record. Avro "Lancaster" Mk.1 P. A. 474 Type record No. 1/P1/Lancaster. Investigation of boundary layer conditions on wings. M.O.S. Contract No.6/Aircraft/9807/C. B. 6(a)

Introduction The investigation involves, briefly, the mounting of a wing of 45' sweep-back in a dorsal position on the fuselage of 'Lancaster' P.A.474 such that wing incidence will be variable in flight over a 20 range, i.e. ± 100. A ‘partial chord’ technique for swept wings has been established by the College using a similar wing mounting configuration on an Avro 'Anson' Aircraft and this technique has been applied to the current investigation

Simulation Training in U.K. General Aviation: An Undervalued Aid to Reducing Loss of Control Accidents

Analysis of data from 1,007 U.K. general aviation (GA) accidents demonstrates the predominant cause of accidents is loss of control, exacerbated by a lack of recent flying experience. These are long-standing problems that can be targeted effectively with simulation training. Discussion on training strategies in commercial aviation reinforces the logic of introducing simulation training for the GA pilot. Conclusions drawn affirm the notion that GA safety would benefit from implementation of regulated simulation training

Flight trails of a rocket-propelled transonic research model: The R.A.E.-Vickers rocket model. Parts I to IV

The development of the gas turbine which provided large thrusts from comparatively small front areas, and at the same time retained its thrust efficiency at high speeds, introduced the possibility of building a supersonic aeroplane. Existing aeroplanes displayed marked longitudinal trim changes at high subsonic speeds, and to pursue these problems into the transonic field, problems which must be solved before the supersonic aeroplane can fly, the Royal Aircraft Establishment in 1945 embarked upon a programme of research using air-launched rocket-propelled models. From the first conception of a simple model the research vehicle grew to a complex model aeroplane complete with auto-pilot, liquid-fuel rocket motor and radio telemetering equipment, aft-launched at 36,000 ft over a ground radar station. The first model, complete with prototype equipment was lost in turbulent air. On the second model launched the rocket motor failed to ignite. There was a period of 12 months further development of the rocket motor and ignition system, followed by the launch in October, 1948 of the third complete model. This model flew satisfactorily and the flight is analysed in this report. The model reached a maximum speed of M = 1.38. The static-pressure variations on the nose pitot-static-tube agree with available information, when allowance is made for the altitude change during flight. There is substantial agreement between measured thrust, longitudinal acceleration and drag, and the latter is in reasonable agreement with that predicted from wind-tunnel tests. The recorded tailplane angle agrees with that calculated from the instructions given to the auto-pilot, and with the predictions from wind-tunnel tests. The main body of the report contains a historical review of the project, brief descr{ptions of the test vehicle and experimental techniques, and the detailed analysis of the final successful flight trial. In a concluding section the project is discussed critically ; it is considered that the work done has shown the experimental method to be an exceedingly difficult one, and that the results it gives do not justify the effort it demands. No further developments are proposed, as alternative transonic research techniques have in the meantime been developed. In a series of appendices are given detailed descriptions of the test vehicle and its ancillary equipment, of the development work leading up to the final trial and of the experimental equipment and techniques. These detailed appendices will be of interest only to the specialist

The Lean Enterprise Model “A Lean Enterprise Reference Tool”

Lean Aircraft Initiative Plenary Workshop presentatio