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排序方式: 共有199条查询结果,搜索用时 15 毫秒
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A new approach is introduced for turbidite modeling, leveraging the potential of computational fluid dynamics methods to simulate the flow processes that led to turbidite formation. The practical use of numerical flow simulation for the purpose of turbidite modeling so far is hindered by the need to specify parameters and initial flow conditions that are a priori unknown. The present study proposes a method to determine optimal simulation parameters via an automated optimization process. An iterative procedure matches deposit predictions from successive flow simulations against available localized reference data, as in practice may be obtained from well logs, and aims at convergence towards the best-fit scenario. The final result is a prediction of the entire deposit thickness and local grain size distribution. The optimization strategy is based on a derivative-free, surrogate-based technique. Direct numerical simulations are performed to compute the flow dynamics. A proof of concept is successfully conducted for the simple test case of a two-dimensional lock-exchange turbidity current. The optimization approach is demonstrated to accurately retrieve the initial conditions used in a reference calculation. 相似文献
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C. N. Bailey J. S. Adams S. R. Bandler R. P. Brekosky J. A. Chervenak M. E. Eckart F. M. Finkbeiner R. L. Kelley D. P. Kelly C. A. Kilbourne F. S. Porter J. E. Sadleir S. J. Smith 《Journal of Low Temperature Physics》2012,167(3-4):121-128
Weak link behavior in transition-edge sensor (TES) microcalorimeters creates the need for a more careful characterization of a device’s thermal characteristics through its transition. This is particularly true for small TESs where a small change in the bias current results in large changes in effective transition temperature. To correctly interpret measurements, especially complex impedance, it is crucial to know the temperature-dependent thermal conductance, G(T), and heat capacity, C(T), at each point through the transition. We present data illustrating these effects and discuss how we overcome the challenges that are present in accurately determining G and T from I–V curves. We also show how these weak link effects vary with TES size. Additionally, we use this improved understanding of G(T) to determine that, for these TES microcalorimeters, Kaptiza boundary resistance dominates the G of devices with absorbers while the electron-phonon coupling also needs to be considered when determining G for devices without absorbers 相似文献
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Austenitic stainless steels have a high potential for the use in separating safeguards of machine tools based on the TRIP
(Transformation Induced Plasticity) effect. The problem with these materials is the high variance of the alloy composition.
Therefore, the specific penetration resistance W
D,spec varies significantly. The presented research analyses the impact of material specific parameters on the specific penetration
resistance W
D,spec and the FEA simulation of impact tests. The result of the project is the knowledge of the penetration resistance and hence
the security (factor of safety) against penetration. 相似文献
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Eckart Edye 《化学,工程师,技术》1980,52(11):874-878
More light products from crude oil – A challenge to the oil industry . A new long-term pattern of demand for oil is evolving mainly due to the politically limited availability of crude oil and increasing prices. For the Federal Republic of Germany an essentially constant level of demand for naphtha and gasoline is expected with a shrinking demand for distillate and fuel oil. The expected pattern cannot be met by the currently predominating hydroskimming process. Technological possibilities and development of conversion processes are emphasized in this article: Thermal catalytic and hydrocracking as well as hydroconverting for steam cracker feed generation. Increasing importance is predicted for residue cracking. Oil will continue to make a major contribution and the oil industry will be able to keep step with product demand. 相似文献
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A SOUnding Rocket Compere Experiment (SOURCE) is prepared for launch in spring 2008 and shall deliver approximately 360 s of microgravity time. The experiment is intended to partially fulfill the scientific objectives of the European Space Agency Microgravity Applications Program project AO-2004-111 (Convective boiling and condensation). One of the tasks of this experiment is the investigation of capillary dominated flow at a heated wall. The SOURCE experiment will also serve the needs of the COMPERE research group whose mandate is to investigate the behavior of propellant in spacecraft tanks. SOURCE is a benchmark type of experiment on fluid behavior in tanks to test hypotheses and numerical predictions (quantitative results on a tank scale). Several work packages have been distributed to the Center of Applied Space Technology and Microgravity (ZARM) to manage a part of the preparation of this experiment. Since ZARM acts also as a principal investigator, the subject of surface tension driven flows is one of the main topics. It includes the design of the experimental setup to study free surface behavior as well as the numerical predictions to quantify the heat transfer at a non-isothermal boundary condition in the absence of gravity. 相似文献
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