A multi-scale method for rarefied and continuum gas flows based on Fokker-Planck model

2016 ◽  
Author(s):  
Fei Fei ◽  
Zhao Hui Liu ◽  
Jun Zhang ◽  
Chu Guang Zheng
Keyword(s):  
Gas Flows ◽  
Multi Scale ◽  
Scale Method ◽  
Fokker Planck

Wavelet Multi-Scale Solution for Deflection of Thin Rectangular Plates under Temperature

2012 ◽  
Vol 166-169 ◽  
pp. 2871-2875
Author(s):  
Yan Chang Wang ◽  
Ke Liang Ren ◽  
Yan Dong ◽  
Ming Guang Wu
Keyword(s):  
Differential Equations ◽  
Rectangular Plate ◽  
Thermal Environment ◽  
Operational Matrix ◽  
Rectangular Plates ◽  
Thin Rectangular Plate ◽  
Multi Scale ◽  
Scale Method ◽  
The Matrix ◽  
Operational Matrix Of Integration

To consider the deformation of thin rectangular plate under temperature. In this paper, the wavelet multi-scale method was used to solve the thin plate governing differential equations with four different initial or boundary conditions. An operational matrix of integration based on the wavelet was established and the procedure for applying the matrix to solve the differential equations was formulated, and got the deflection of thin rectangular plates under temperature. The result provides a theoretical reference for solving thin rectangular plate deflection in thermal environment using multi-scale approach.

Electrokinetic Research on the Dispersion Behavior of Nano-Ceria Particles in Concentrated Suspensions

2015 ◽  
Vol 645-646 ◽  
pp. 394-399
Author(s):  
Wei Gao ◽  
Qi Long Wei ◽  
Ling Ding ◽  
Xiao Yuan Li ◽  
Chao Wang ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Rheological Properties ◽  
Concentrated Suspensions ◽  
Tem Analysis ◽  
Concentrated Suspension ◽  
Original Solution ◽  
Multi Scale ◽  
Scale Method ◽  
Dispersion Behavior ◽  
Significant Difference

A multi-scale method was developed, which utilized intrinsic relationships among zeta potential of particles, rheological properties of suspensions and particle size distribution (PSD), to analyze dispersion behavior of nanoparticles in concentrated suspensions. It was found that PSD of a kind of nanoceria particles by dynamic light scattering (DLS) method in solution A with concentration 5 wt% accorded well with that by direct TEM analysis, which meant the particles had been dispersed well. However, there had a significant difference when the concentration was increased to 20 wt%. When particles concentration increased from 5 wt% to 20 wt%, zeta potential in solution A changed from-150 mV to-100 mV, while zeta potential in solution B changed from-35mV to-45 mV. Variations of zeta potential of particles accorded well with rheological properties of suspensions too, from phenomenological models. When the suspensions composed by solution A and the nanoparticles with concentration about 20 wt% was diluted with its original solution to 5 wt%, the PSD of nanoceria could be measured indirectly, which accorded well with both that of a suspension prepared directly with near concentration and that from TEM images. Then a method to measure PSD of nanoparticles in concentrated suspension was brought forward.

A Bridging Scale Method for Multi-scale Analysis of Granular Materials

2010 ◽  
Author(s):  
Xikui Li ◽  
Ke Wan ◽  
Jane W. Z. Lu ◽  
Andrew Y. T. Leung ◽  
Vai Pan Iu ◽  
...  
Keyword(s):  
Granular Materials ◽  
Scale Analysis ◽  
Multi Scale ◽  
Scale Method ◽  
Bridging Scale Method ◽  
Multi Scale Analysis

scholarly journals Contact modelling of highly heterogeneous friction material for braking applications

2020 ◽  
Vol 21 (5) ◽  
pp. 507
Author(s):  
Essosnam Arfa ◽  
Vincent Magnier ◽  
Philippe Dufrénoy ◽  
Géry de Saxcé
Keyword(s):  
Computing Time ◽  
Heterogeneous Material ◽  
Friction Material ◽  
Significant Advance ◽  
Numerical Homogenization ◽  
Multi Scale ◽  
Scale Method ◽  
Contact Rigidity ◽  
Fem Method ◽  
Contact Modelling

Friction brakes are increasingly undergoing considerable development to improve their durability, efficiency, maintenance costs and environmental impact. Nevertheless, to achieve this, it is necessary to understand the different mechanisms involved in contact that are multi-scale and multi-physical in nature. On the multi-scale aspect, it is well known experimentally that heterogeneities have a pre-weighted role on performance without being able to explain it. Thus, modelling seems to be a good way to better understand the influence of these heterogeneities, provided that we have a multi-scale method to consider them. The objective of this article is therefore to propose a methodology for simulating contact in the presence of heterogeneous materials. The strategy consists in enriching the contact rigidity in terms of behaviour by a method of numerical homogenization. The significant advance of this article lies in the consideration of contact within the technique of numerical homogenization of a heterogeneous material. The strategy is then validated by comparing the mechanical fields between the proposed method and an explicitly meshed case. One of the main contributions of this work is the reduction in computing time compared to the traditional FEM method.

scholarly journals Separating Leaf and Wood Points in Terrestrial Laser Scanning Data Using Multiple Optimal Scales

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1852 ◽  
Author(s):  
Junjie Zhou ◽  
Hongqiang Wei ◽  
Guiyun Zhou ◽  
Lihui Song
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Terrestrial Laser Scanning ◽  
Geometric Features ◽  
Optimization Strategy ◽  
Running Time ◽  
Multi Scale ◽  
Scale Method ◽  
Optimal Scale

The separation of leaf and wood points is an essential preprocessing step for extracting many of the parameters of a tree from terrestrial laser scanning data. The multi-scale method and the optimal scale method are two of the most widely used separation methods. In this study, we extend the optimal scale method to the multi-optimal-scale method, adaptively selecting multiple optimal scales for each point in the tree point cloud to increase the distinctiveness of extracted geometric features. Compared with the optimal scale method, our method achieves higher separation accuracy. Compared with the multi-scale method, our method achieves more stable separation accuracy with a limited number of optimal scales. The running time of our method is greatly reduced when the optimization strategy is applied.

Sign in / Sign up

Export Citation Format

Share Document