The evaluation of multicenter integrals by polished brute force techniques: I. Analysis, numerical methods, and computational design of the potential-charge distribution scheme

2009 ◽  
Vol 1 (S1) ◽  
pp. 375-401 ◽  
Author(s):  
Arnold C. Wahl ◽  
Robert H. Land
Keyword(s):  
Numerical Methods ◽  
Charge Distribution ◽  
Computational Design ◽  
Brute Force ◽  
Multicenter Integrals ◽  
Distribution Scheme

3D Ice Accretion Simulation for Complex Configuration Basing on Improved Messinger Model

2014 ◽  
Vol 1025-1026 ◽  
pp. 148-155
Author(s):  
Cheng Xiang Zhu ◽  
Chun Ling Zhu ◽  
Bin Fu
Keyword(s):  
Numerical Methods ◽  
Flow Field ◽  
Turbulence Model ◽  
Calculated Result ◽  
Complex Configuration ◽  
Ice Accretion ◽  
Improved Method ◽  
Experiment Data ◽  
Distribution Scheme ◽  
Good Agreement

Ice accretion on 3D complex configuration is studied by numerical methods. The flow field is obtained by using Fluent 6.0 with a S-A turbulence model. Droplet trajectories and impingement characteristics are obtained by using the Eulerian approach. Ice shape is calculated based on the improved Messinger model with a new runback distribution scheme. By applying the method presented in this paper, ice accretion on NACA0012 is computed and the results are in good agreement with the available experiment data. It preliminarily shows that the improved method in this paper is feasible, Meanwhile, ice accretion on a four-element wing is studied. According to the analysis of the calculated result, the method presented in the paper can correctly simulate the ice accretion on 3D complex configuration.

Study of charge transfer in FeTi

1983 ◽  
Vol 41 ◽  
pp. 296-297
Author(s):  
J. Taft∅
Keyword(s):  
Charge Transfer ◽  
Charge Distribution ◽  
Electron Scattering ◽  
Periodic System ◽  
Electron Distribution ◽  
Scattering Amplitude ◽  
Transition Elements ◽  
Hartree Fock ◽  
Cscl Structure ◽  
The Right

It is well known that for reflections corresponding to large interplanar spacings (i.e., sin θ/λ small), the electron scattering amplitude, f, is sensitive to the ionicity and to the charge distribution around the atoms. We have used this in order to obtain information about the charge distribution in FeTi, which is a candidate for storage of hydrogen. Our goal is to study the changes in electron distribution in the presence of hydrogen, and also the ionicity of hydrogen in metals, but so far our study has been limited to pure FeTi. FeTi has the CsCl structure and thus Fe and Ti scatter with a phase difference of π into the 100-ref lections. Because Fe (Z = 26) is higher in the periodic system than Ti (Z = 22), an immediate “guess” would be that Fe has a larger scattering amplitude than Ti. However, relativistic Hartree-Fock calculations show that the opposite is the case for the 100-reflection. An explanation for this may be sought in the stronger localization of the d-electrons of the first row transition elements when moving to the right in the periodic table. The tabulated difference between fTi (100) and ffe (100) is small, however, and based on the values of the scattering amplitude for isolated atoms, the kinematical intensity of the 100-reflection is only 5.10-4 of the intensity of the 200-reflection.

Numerical Methods

2019 ◽  
Author(s):  
Rajesh Kumar Gupta
Keyword(s):  
Numerical Methods
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