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71.
72.
Volker John Petr Knobloch Simona B. Savescu 《Computer Methods in Applied Mechanics and Engineering》2011,200(41-44):2916-2929
Stabilized finite element methods for convection-dominated problems require the choice of appropriate stabilization parameters. From numerical analysis, often only their asymptotic values are known. This paper presents a general framework for optimizing stabilization parameters with respect to the minimization of a target functional. Exemplarily, this framework is applied to the SUPG finite element method and the minimization of a residual-based error estimator, an error indicator, and a functional including the crosswind derivative of the computed solution. Benefits of the basic approach are demonstrated by means of numerical results. 相似文献
73.
Matthias Augustin Alfonso Caiazzo André Fiebach Jürgen Fuhrmann Volker John Alexander Linke Rudolf Umla 《Computer Methods in Applied Mechanics and Engineering》2011,200(47-48):3395-3409
The performance of several numerical schemes for discretizing convection-dominated convection–diffusion equations will be investigated with respect to accuracy and efficiency. Accuracy is considered in measures which are of interest in applications. The study includes an exponentially fitted finite volume scheme, the Streamline-Upwind Petrov–Galerkin (SUPG) finite element method, a spurious oscillations at layers diminishing (SOLD) finite element method, a finite element method with continuous interior penalty (CIP) stabilization, a discontinuous Galerkin (DG) finite element method, and a total variation diminishing finite element method (FEMTVD). A detailed assessment of the schemes based on the Hemker example will be presented. 相似文献
74.
In this paper, we present novel developments in aerodynamic shape optimization based on shape calculus as well as the proper treatment of aleatoric uncertainties in the field of aerodynamic design. 相似文献
75.
Insu Paek Luc Mongeau James E. Braun 《Journal of Mechanical Science and Technology》2010,24(9):1781-1791
The performance of a working prototype, operated with and without water flow through the heat exchangers, was measured and found to be in reasonably close agreement to predictions from a simulation code, DELTAE, based on linear thermoacoustic theory. Further analysis and DELTAE simulations showed that the coefficient of performance may be significantly reduced when the stack temperature profile becomes non-linear, i.e. when the system is operated for a temperature span smaller than the optimal value for a given stack length. Guidelines to avoid this condition are provided. 相似文献
76.
The Suspicion of Simulation. A Psychiatric Case History between Appropriation and Disciplinary Action at the End of the 19th
Century.
This case history explores how the question of agency was dealt with historically in two developing, normative orders of deviant
behaviour. Examining the institutional career of the supposed adulterer, marriage swindler, and craft baker, we can trace
the different observation regimes and systems of knowledge acquisition in the prison and in psychiatry. In both institutions
there was talk of simulated madness; the explanations, however, were different. For the prison doctors and civil servants,
the baker was a criminal; his deviant behaviour was a matter of consciously planned-out deception. For the examining psychiatrist,
on the other hand, he was mentally ill and could not be held responsible for his own behaviour. 相似文献
77.
Template‐Directed Directionally Solidified 3D Mesostructured AgCl–KCl Eutectic Photonic Crystals 下载免费PDF全文
78.
Prof. Dr. Andreas Leson Gregor Englberger Daniel Hammer Stefan Makowski Carl‐Friedrich Meyer Michael Leonhard Hans‐Joachim Scheibe Volker Weihnacht 《真空研究与实践》2015,27(4):24-28
Diamond‐like carbon thin films enhance efficiency — laser arc deposition of ta‐C Rising prices for fossil fuels as well as the increasing effects of the climate change due to the emission of greenhouse gases reveal the necessity of saving energy. Low friction coatings have an enormous potential in saving energy. Carbon based coatings — named as DLC coatings — are especially well suited for low friction coatings. In particular hydrogen‐free tetrahedral amorphous carbon (ta‐C) coatings are of great interest due to their extraordinary low wear properties. In addition they show excellent low friction properties and especially in combination with specific lubricants the so‐called super low friction effect. For the deposition of ta‐C coatings PVD methods have to be applied instead of CVD methods as it is the case for conventional DLC coatings. We have developed a deposition method which is based on a pulsed arc steered by a laser (Laser‐Arc). This allows us to use large cathodes resulting in a high long‐term stability. Furthermore, the carbon plasma source can be combined with a filtering unit removing almost all droplets and particles, which usually are characteristic for an arc process. The resulting Laser‐Arc source allows for the deposition of smooth and virtually defect‐free ta‐C coatings with a competitive deposition rate. 相似文献
79.
Photonic Crystals: Template‐Directed Directionally Solidified 3D Mesostructured AgCl–KCl Eutectic Photonic Crystals (Adv. Mater. 31/2015) 下载免费PDF全文
80.
Gianoglio Dario Ciftci Nevaf Armstrong Sarah Uhlenwinkel Volker Battezzati Livio 《Metallurgical and Materials Transactions A》2021,52(9):3750-3758
Metallurgical and Materials Transactions A - Gas atomization is the most used powder production technique since it provides good control on particles shape, surface oxidation and dimension. It is a... 相似文献