Oxidation of Suspended Stacked Silicon Nanowire for Sub-10nm Cross-Section Shape Optimization

2019 ◽  
Vol 13 (1) ◽  
pp. 195-199 ◽  
Author(s):  
Alexandre Hubert ◽  
Jean-Philippe Colonna ◽  
Stéphane Bécu ◽  
Cécilia Dupré ◽  
Virginie Maffini-Alvaro ◽  
...  
Keyword(s):  
Shape Optimization ◽  
Cross Section ◽  
Silicon Nanowire ◽  
Cross Section Shape ◽  
Section Shape

scholarly journals Shape Optimization of the Cross-Section for Noncircular Hypersonic Missile Forebody

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jingfan Chen ◽  
Xiaoqiang Fan ◽  
Bing Xiong ◽  
Yi Wang
Keyword(s):  
Shape Optimization ◽  
Cross Section ◽  
Parametric Modeling ◽  
Cross Section Shape ◽  
Section Shape ◽  
The Cross ◽  
Wide Speed Range ◽  
Optimization Efficiency ◽  
Drag Ratio ◽  
Lift To Drag Ratio

In the hypersonic regime, noncircular missiles have attracted significant attention from researchers. The paper first summarizes the development and present situation of the noncircular missiles at home and abroad. Previous research found that the cross-section shape of missiles has a direct influence on the aerodynamics performance. To find the best cross-section shape in terms of lift-drag-ratio, an efficient and robust shape optimization framework is developed. Class/shape function transformation (CST) method and power-law curve are introduced to complete the parametric modeling of the noncircular missile. The evolutionary algorithm has been utilized to improve the optimization efficiency. A combination of script and journal files is written to automate the CAD loft, mesh generation, and CFD simulations process. Finally, the forebody section of a missile body is chosen as an example to deliver the whole optimization steps. The optimization results show that the lift-to-drag ratio increases from 1.8 to 2.4 when the hypersonic missile forebody cruises at the design condition. The results also demonstrate that the optimized configuration has a better aerodynamic performance than the original one over a wide speed range from Mach 2 to 8 and a wide attack of angle range from 0 to 30.

scholarly journals Designing for People’s Safety on Flooded Streets: Uncertainties and the Influence of the Cross-Section Shape, Roughness and Slopes on Hazard Criteria

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2119
Author(s):  
Luís Mesquita David ◽  
Rita Fernandes de Carvalho
Keyword(s):  
Cross Section ◽  
Overland Flow ◽  
Rectangular Cross Section ◽  
Safety Hazard ◽  
Cross Section Shape ◽  
Section Shape ◽  
Flood Flows ◽  
The Cross ◽  
Flooding Risk

Designing for exceedance events consists in designing a continuous route for overland flow to deal with flows exceeding the sewer system’s capacity and to mitigate flooding risk. A review is carried out here on flood safety/hazard criteria, which generally establish thresholds for the water depth and flood velocity, or a relationship between them. The effects of the cross-section shape, roughness and slope of streets in meeting the criteria are evaluated based on equations, graphical results and one case study. An expedited method for the verification of safety criteria based solely on flow is presented, saving efforts in detailing models and increasing confidence in the results from simplified models. The method is valid for 0.1 m2/s 0.5 m2/s. The results showed that a street with a 1.8% slope, 75 m1/3s−1 and a rectangular cross-section complies with the threshold 0.3 m2/s for twice the flow of a street with the same width but with a conventional cross-section shape. The flow will be four times greater for a 15% street slope. The results also highlighted that the flood flows can vary significantly along the streets depending on the sewers’ roughness and the flow transfers between the major and minor systems, such that the effort detailing a street’s cross-section must be balanced with all of the other sources of uncertainty.

scholarly journals On the shape of cicada’s wing leading-edge cross section

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rachel M. Starkweather ◽  
Svetlana V. Poroseva ◽  
David T. Hanson
Keyword(s):  
Cross Section ◽  
Insect Flight ◽  
Leading Edge ◽  
Flight Performance ◽  
Cross Section Shape ◽  
Section Shape ◽  
First Time

AbstractAn important role that the leading-edge cross-section shape plays in the wing flight performance is well known in aeronautics. However, little is known about the shape of the leading-edge cross section of an insect’s wing and its contribution to remarkable qualities of insect flight. In this paper, we reveal, in the first time, the shape of the leading-edge cross section of a cicada’s wing and analyze its variability along the wing. We also identify and quantify similarities in characteristic dimensions of this shape in the wings of three different cicada species.

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