Aleksandr Shiryaev^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.4, pp. 761-771, 2020, DOI:10.32604/fdmp.2020.09010

Abstract The problem relating to the small-amplitude free capillary oscillations of an encapsulated spherical drop is solved theoretically in the framework of asymptotic methods. Liquids are supposed to be inviscid and immiscible. The formulas derived are presented for different parameters of the inner and outer liquids, including densities, thickness of the outer liquid layer, and the surface and interfacial tension coefficients. The frequencies of oscillation of the encapsulated drop are studied in relation to several “modes” which can effectively be determined in experiments by photo and video analysis. The results are presented in terms of oscillation frequencies reported as a function… More >

Y.C. Liu, C.M. Fan, H.F. Chan, S.S. Hsiao

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.1, pp. 31-32, 2011, DOI:10.3970/icces.2011.019.031

Abstract The harbor oscillation problem, which is governed by inhomogeneous Helmholtz equation, is analyzed by the combination of the method of fundamental solutions (MFS) and method of particular solutions (MPS). The governed inhomogeneous Helmholtz equation is derived from the mild-slope equation and potential theory. The numerical solutions of the velocity potential of the harbor oscillation problem are decomposed as the homogeneous solution and the particular solution. While the particular solution is obtained by the MPS, the MFS is adopted to analyze the homogeneous solution. The particular solution is expressed as the linear combination of radial basis function, as the homogeneous solution… More >

Somchai Sriyab¹, Wannapong Triampo²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.3, pp. 51-52, 2009, DOI:10.3970/icces.2009.013.051

Abstract Understanding of Bacteria cell division is essential for an understanding of microorganism as well as the origin of the life. Particularly, in cell division process of \emph {E. coli}, Min proteins (MinD and MinE) play crucial roles to regulate the dividing dynamics physically via their oscillatory dynamics from pole to pole. In this work, we have developed a numerical scheme based on the mesoscopic Lattice Boltzmann Method (LBM) to simulate the coarse-grained coupled reaction-diffusion equations model used to describe the MinD/MinE interaction in two dimensions. Biologically, we have focused on investigating how the protein copies affect the oscillation patterns as… More >

Waipot Ngamsaad, Wannapong Triampo¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.2, pp. 49-50, 2009, DOI:10.3970/icces.2009.013.049

Abstract The Min-proteins oscillation in \emph {E. coli} has an essential role in controlling the accuracy placement of cell-division septum at the middle cell zone of the bacteria. This biochemical process has been successfully described by a set of reaction-diffusion equation at the macroscopic level [1]. Recently, a mesoscopic modeling by the lattice Boltzmann method (LBM) has been proposed to simulate the Min-proteins oscillation [2]. However, as pointed out by Zhang et al., the standard boundary conditions are not accuracy for a class of dispersion transport modeled by LBM [3]. In this present work, we investigated the boundary effects in LBM… More >

J.S. Ren^*

Molecular & Cellular Biomechanics, Vol.7, No.4, pp. 213-224, 2010, DOI:10.3970/mcb.2010.007.213

Abstract Dynamic analysis of an axially stretched arterial wall with collagen fibers distributed in two preferred directions under a suddenly applied constant internal pressure along with the possibility of the formation and rupture of aneurysm are examined within the framework of nonlinear dynamics. A two layer tube model with the fiber-reinforced composite-based incompressible anisotropic hyper-elastic material is employed to model the mechanical behavior of the arterial wall. The maximum amplitudes and the phase diagrams are given by numerical computation of the differential relation. It is shown that the arterial wall undergoes nonlinear periodic oscillation and no aneurysms are formed under the… More >

Zhijie Huang^1,2,3, Zuyu Chen^1,2,3, Xiaodan Ren^4,*, Jing Hu³, Xuedong Zhang³, Lu Hai⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 139-155, 2019, DOI:10.31614/cmes.2019.04596

Abstract Damage and threats to hydraulic and submarine structures by underwater explosions (UNDEXs) have raised much attention. The centrifuge model test, compared to prototype test, is a more promising way to examine the problem while reducing cost and satisfying the similitude requirements of both Mach and Froude numbers simultaneously. This study used a systematic approach employing centrifuge model tests and numerical simulations to investigate the effects of UNDEXs on an air-backed steel plate. Nineteen methodical centrifuge tests of UNDEXs were conducted. The shock wave pressure, bubble oscillation pressure, acceleration and the strain of the air-backed steel plate were recorded and compared… More >

Xiaomin An¹, Min Xu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.6, pp. 601-629, 2014, DOI:10.3970/cmes.2014.098.601

Abstract Nonlinear aeroelasticity, caused by the interaction between nonlinear fluid and geometrically nonlinear structure, is studied by an improved CFD and CSD coupled program. An AUSMpw+ flux splitting scheme, combined with an implicit time marching technology and geometric conservation law, is utilized to solve unsteady aerodynamic pressure; The finite element co-rotational theory is applied to model geometrically nonlinear two-dimensional and three-dimensional panels, and a predictor-corrector program with an approximately energy conservation is developed to obtain nonlinear structure response. The two solvers are connected by Farhat’s second order loosely coupled method and the aerodynamic loads and structural displacements are transferred by boundary… More >

Mikael A. Langthjem¹, Masami Nakano²

CMES-Computer Modeling in Engineering & Sciences, Vol.96, No.4, pp. 227-241, 2013, DOI:10.3970/cmes.2013.096.227

Abstract This paper is concerned with a mathematical model of a simple axisymmetric silencer-like model, consisting of a hole-tone feedback system equipped with a tailpipe. The unstable shear layer is modeled via a discrete vortex method, based on axisymmetric vortex rings. The aeroacoustic model is based on the Powell- Howe theory of vortex sound. Boundary integrals are discretized via the boundary element method; but the tailpipe is represented by the exact (one-dimensional) solution. It is demonstrated though numerical examples that this numerical model can display lock-in of the self-sustained flow oscillations to the resonant acoustic oscillations. More >

Hong-Hua Dai^1,2, Matt Schnoor², Satya N. Atluri²

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.5, pp. 459-498, 2012, DOI:10.3970/cmes.2012.084.459

Abstract In this study, the harmonic and 1/3 subharmonic oscillations of a single degree of freedom Duffing oscillator with large nonlinearity and large damping are investigated by using a simple point collocation method applied in the time domain over a period of the periodic solution. The relationship between the proposed collocation method and the high dimensional harmonic balance method (HDHB), proposed earlier by Thomas, Dowell, and Hall (2002), is explored. We demonstrate that the HDHB is not a kind of "harmonic balance method" but essentially a cumbersome version of the collocation method. In using the collocation method, the collocation-resulting nonlinear algebraic… More >

A. Idesman ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.71, No.2, pp. 111-148, 2011, DOI:10.3970/cmes.2011.071.111

Abstract The paper deals with the following issues of existing time-integration methods for a semi-discrete system of elastodynamics equations: a) the quantification and the suppression of spurious high frequencies; b) the selection of the amount of numerical dissipation for a time-integration method; and c) accurate time integration of low modes. The finite element method used in the paper or other methods can be applied for the space discretization. A new two-stage time-integration procedure consisting of basic computations and the filtering stage is developed. For accurate integration of all frequencies, a time-integration method with zero (or small) numerical dissipation is applied for… More >