Open Access
ARTICLE
M. Marigo1,2, D. L. Cairns1, M. Davies1, M. Cook3,A. Ingram2,4,5, E. H. Stitt1
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.3, pp. 217-238, 2010, DOI:10.3970/cmes.2010.059.217
Abstract In this work the complex motion of the Turbulamixer has been measured by Multiple-Positron Emission Particle Tracking (Multiple PEPT) in order to set-up a DEM numerical model. Positron emitting radioactive tracers were attached to three of the pivot bearings on the shaft of the mixer to enable the rotation and translation of the mixer chamber to be tracked in the PEPT camera. The measured movement was mathematically reconstructed and imported into DEM in order to apply the same movement to the modelled vessel.
The three-dimensional motion of particles in a vessel located in the Turbula mixer was then calculated using… More >
Open Access
ARTICLE
Chih-Wen Chang1, Chein-Shan Liu2
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.3, pp. 239-274, 2010, DOI:10.3970/cmes.2010.059.239
Abstract In this article, we propose a backward group preserving scheme (BGPS) to tackle the multi-dimensional backward heat conduction problem (BHCP). The BHCP is well-known as severely ill-posed because the solution does not continuously depend on the given data. When eight numerical examples (including nonlinear and nonhomogeneous BHCP, and Neumann and Robin conditions of homogeneous BHCP) are examined, we find that the BGPS is applicable to the multi-dimensional BHCP. Even with noisy final data, the BGPS is also robust against disturbance. The one-step BGPS effectively reconstructs the initial data from the given final data, which with a suitable grid length produces… More >
Open Access
ARTICLE
Ji Joong Moon1, Seung Jo Kim1, Minhyung Lee2
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.3, pp. 275-300, 2010, DOI:10.3970/cmes.2010.059.275
Abstract This paper describes the parallelization of contact/impact simulation for fracture modeling of brittle materials using a node separation scheme (NSS). We successfully demonstrated the fracture modeling of brittle materials using a cohesive fracture model. Since a NSS continuously generates new free surfaces as the computation progresses, the methodology requires increased computational time. To perform a simulation within a reasonable time period, a parallelization study is conducted. Particular methods for effective parallelization, especially for brittle materials, are described in detail. The crucial and most difficult strategy is the management of the data structure and communication needed to handle new contact nodes… More >
Open Access
ARTICLE
Chein-Shan Liu1, Weichung Yeih2, Satya N. Atluri3
CMES-Computer Modeling in Engineering & Sciences, Vol.59, No.3, pp. 301-324, 2010, DOI:10.3970/cmes.2010.059.301
Abstract When problems in engineering and science are discretized, algebraic equations appear naturally. In a recent paper by Liu and Atluri, non-linear algebraic equations (NAEs) were transformed into a nonlinear system of ODEs, which were then integrated by a method labelled as the Fictitious Time Integration Method (FTIM). In this paper, the FTIM is enhanced, by using the concept of arepellorin the theory ofnonlinear dynamical systems, to situations where multiple-solutions exist. We label this enhanced method as MSFTIM. MSFTIM is applied and illustrated in this paper through solving boundary-layer problems, boundary-value problems, and eigenvalue problems with multiple solutions. More >