A radial basis function based ghost cell method with improved mass conservation for complex moving boundary flows

2018 ◽  
Vol 176 ◽  
pp. 210-225 ◽  
Author(s):  
Jianjian Xin ◽  
Fulong Shi ◽  
Qiu Jin ◽  
Chao Lin
Keyword(s):  
Radial Basis Function ◽  
Basis Function ◽  
Moving Boundary ◽  
Mass Conservation ◽  
Ghost Cell ◽  
Cell Method ◽  
Radial Basis ◽  
Ghost Cell Method

A Radial Basis Function–Based Ghost Cell Method for Complex Rigid or Flexible Moving Boundary Flows

2020 ◽  
Vol 18 (01) ◽  
pp. 2050025
Author(s):  
Jianjian Xin ◽  
Zhenlei Chen ◽  
Fan Shi ◽  
Fulong Shi ◽  
Qiu Jin
Keyword(s):  
Radial Basis Function ◽  
Basis Function ◽  
Moving Boundary ◽  
Interpolation Method ◽  
Immersed Boundary ◽  
Ghost Cell ◽  
Cell Method ◽  
Radial Basis ◽  
Ghost Cell Method ◽  
Irregular Boundaries

A radial basis function (RBF)-based ghost cell method is presented to simulate flows around a rigid or flexible moving hydrofoil on a Cartesian grid. A compactly supported radial basis function (CSRBF) is introduced to the ghost cell immersed boundary method to treat the complex flexible boundaries in the fluid. The results indicate that this RBF representation method can accurately track tempo-spatially varied interfaces and avoid the identification failure encountered in original RBF. In addition, an interface cell interpolation method is developed to treat the irregular boundaries such as sharp points and thin boundaries. Solution quality is improved by constructing the interface cells along the local irregular boundaries, instead of the ghost cells. To validate the proposed method, uniform flows around stationary and pitching hydrofoils are simulated. Then, a flexible hydrofoil undulating in the fluid is simulated. Good agreements are obtained by comparing the present results with the reference results. Furthermore, the relationship between the oscillation frequency and the force coefficient is studied. Also, generation mechanism of the thrust force is explained.

Radial Basis Function Methods for Fractional Derivative Applications

2015 ◽  
Author(s):  
Zhuo-Jia Fu
Keyword(s):  
Fractional Derivative ◽  
Radial Basis Function ◽  
Basis Function ◽  
Moving Boundary ◽  
Particle Method ◽  
Meshless Methods ◽  
Particular Solutions ◽  
Fractional Derivative Model ◽  
Radial Basis ◽  
Particular Solution

In recent decades, the theoretical researches and experimental results show that fractional derivative model can be a powerful tool to describe the contaminant transport through complex porous media and the dynamic behaviors of real viscoelastic materials. Consequently, growing attention has been attracted to numerical solution of fractional derivative model. Radial basis function (RBF) meshless technique is one of the most popular and powerful numerical methods, which are mathematically simple, and avoid troublesome mesh generation for high-dimensional problems involving irregular or moving boundary. Recently, RBF-based meshless methods, such as the Boundary Particle Method and the Method of Approximate Particular Solutions, have been successfully applied to fractional derivative problems. The Boundary Particle Method is one of truly boundary-only RBF collocation schemes, which employs both the semi-analytical basis functions to approximate the FDE solutions. Inspired by the boundary collocation RBF techniques, the Method of Approximate Particular Solutions is one of the domain-type RBF collocation schemes with easy-to-use merit, which employs the particular solution RBFs for the solution of FDEs. This study will make a numerical investigation on the abovementioned RBF meshless methods to fractional derivative problems. The convergence rate, numerical accuracy and stability of these schemes will be examined through several benchmark examples.

scholarly journals Animproved ghost cell method for flow simulation involving static and moving boundary

2019 ◽  
Vol 68 (12) ◽  
pp. 124703
Author(s):  
Feng Wei ◽  
Liang Jin ◽  
Jun Liu ◽  
Feng Ding ◽  
Xin-Ping Zheng
Keyword(s):  
Moving Boundary ◽  
Flow Simulation ◽  
Ghost Cell ◽  
Cell Method ◽  
Ghost Cell Method
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