scholarly journals Quantum battles in attoscience: tunnelling

2021 ◽  
Vol 75 (7) ◽  
Author(s):  
Cornelia Hofmann ◽  
Alexander Bray ◽  
Werner Koch ◽  
Hongcheng Ni ◽  
Nikolay I. Shvetsov-Shilovski
Keyword(s):  
Quantum Mechanics ◽  
Numerical Investigation ◽  
Cross Section ◽  
Computational Modelling ◽  
Unanswered Question ◽  
Attosecond Physics

Abstract What is the nature of tunnelling? This yet unanswered question is as pertinent today as it was at the dawn of quantum mechanics. This article presents a cross section of current perspectives on the interpretation, computational modelling, and numerical investigation of tunnelling processes in attosecond physics as debated in the Quantum Battles in Attoscience virtual workshop 2020. Graphic abstract

NUMERICAL INVESTIGATION OF CuO-WATER NANOFLUID IN DIFFERENT GEOMETRY CROSS-SECTION

2011 ◽  
Author(s):  
M Bahiraei ◽  
S. I. Vasefi ◽  
K. Zabihi ◽  
S. M. Hoseinalipour
Keyword(s):  
Numerical Investigation ◽  
Cross Section

Numerical Investigation on Film Cooling Performance of Fusiform Diffusion Holes

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Bai-Tao An ◽  
Jian-Jun Liu
Keyword(s):  
Numerical Investigation ◽  
Cross Section ◽  
Film Cooling ◽  
Discharge Coefficient ◽  
Cross Sectional ◽  
Cooling Performance ◽  
Blowing Ratio ◽  
Section Area ◽  
Two Sides ◽  
Dynamics Method

This paper presents a numerical investigation of the film-cooling performance of a kind of diffusion hole with a fusiform cross section. Relative to the rectangular diffusion hole, the up- and/or downstream wall of the fusiform diffusion hole is outer convex. Under the same metering section area, six fusiform diffusion holes were divided into two groups with cross-sectional widths of W = 1.7D and W = 2.0D, respectively. Three fusiform cross section shapes in each group included only downstream wall outer convex, only upstream wall outer convex, or a combination of both. Simulations were performed in a flat plate model using a 3D steady computational fluid dynamics method under an engine-representative condition. The simulation results showed that the fusiform diffusion hole with only an outer convex upstream wall migrates the coolant laterally toward the hole centerline, and then forms or enhances a tripeak effectiveness pattern. Conversely, the fusiform diffusion hole with an outer convex downstream wall intensely expands the coolant to the hole two sides, and results in a bipeak effectiveness pattern, regardless of the upstream wall shape. Compared with the rectangular diffusion holes, the fusiform diffusion holes with only an upstream wall outer convex significantly increase the overall effectiveness at high blowing ratios. The increased magnitude is approximately 20% for the hole of W = 1.7D at M = 2.5. Besides, the fusiform diffusion holes with an outer convex upstream wall increase the discharge coefficient about 5%, within the moderate to high blowing ratio range.

scholarly journals Quantum Trajectories: Real or Surreal?

Entropy ◽  
2018 ◽  
Vol 20 (5) ◽  
pp. 353 ◽  
Author(s):  
Basil Hiley ◽  
Peter Van Reeth
Keyword(s):  
Quantum Mechanics ◽  
Numerical Investigation ◽  
Quantum Potential ◽  
Quantum Trajectories ◽  
Bohm Trajectories

The claim of Kocsis et al. to have experimentally determined “photon trajectories” calls for a re-examination of the meaning of “quantum trajectories”. We will review the arguments that have been assumed to have established that a trajectory has no meaning in the context of quantum mechanics. We show that the conclusion that the Bohm trajectories should be called “surreal” because they are at “variance with the actual observed track” of a particle is wrong as it is based on a false argument. We also present the results of a numerical investigation of a double Stern-Gerlach experiment which shows clearly the role of the spin within the Bohm formalism and discuss situations where the appearance of the quantum potential is open to direct experimental exploration.

scholarly journals Numerical investigation on detonation cell evolution in a channel with area-changing cross section

2007 ◽  
Vol 50 (6) ◽  
pp. 797-808 ◽  
Author(s):  
Bo Deng ◽  
ZongMin Hu ◽  
HongHui Teng ◽  
ZongLin Jiang
Keyword(s):  
Numerical Investigation ◽  
Cross Section ◽  
Detonation Cell ◽  
Cell Evolution

scholarly journals Experimental and Numerical Investigation of the Flow in a Centrifugal Compressor Volute

1999 ◽  
Author(s):  
D. Hagelstein ◽  
K. Hillewaert ◽  
R. A. Van den Braembussche ◽  
A. Engeda ◽  
R. Keiper ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Wall Friction ◽  
Detailed Knowledge ◽  
Viscous Effects ◽  
Loss Mechanism ◽  
Dissipation Term ◽  
Friction Term ◽  
Operating Points

This paper presents the experimental and numerical investigation of an outward volute of rectangular cross section. The investigation is carried out at the level of - stage performance, - volute performance and - detailed flow field study at selected peripheral positions for various operating points. The objective of the investigation was to gain further knowledge about the flow structure and loss mechanism in the volute. Simultaneously with the experimental investigation, a numerical simulation of the flow in the volute was carried out. A 3D Euler-code was used in which a wall friction term and a tuned artificial dissipation term account for viscous effects. A reasonable agreement between the experimental and numerical results is observed. As a result a good and detailed knowledge about the pressure recovery and loss mechanism in the volute is obtained.

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