Browsing by Publisher "Amer Inst Physics"
Now showing items 1-5 of 5
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A numerical study of the laminar necklace vortex system and its effect on the wake for a circular cylinder
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Publisher and Date:(Amer Inst Physics, 2012)Large eddy simulation (LES) is used to investigate the structure of the laminar horseshoe vortex (HV) system and the dynamics of the necklace vortices as they fold around the base of a circular cylinder mounted on the flat bed of an open channel for Reynolds numbers defined with the cylinder diameter D smaller than 4460. The study concentrates on the analysis of the structure of the HV system in the periodic breakaway sub-regime which is characterized by the formation of three main necklace vortices. ...
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Effects of cylinder Reynolds number on the turbulent horseshoe vortex system and near wake of a surface-mounted circular cylinder
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Publisher and Date:(Amer Inst Physics, 2015)The turbulent horseshoe vortex (HV) system and the near-wake flow past a circular cylinder mounted on a flat bed in an open channel are investigated based on the results of eddy-resolving simulations and supporting flow visualizations. Of particular interest are the changes in the mean flow and turbulence statistics within the HV region as the necklace vortices wrap around the cylinder's base and the variation of the mean flow and turbulence statistics in the near wake in between the channel bed ...
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Modelling of Swelling by the Fluorescence Technique in Kappa Carrageenan Gels
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Publisher and Date:(Amer Inst Physics, 2011)Kappa (-kappa) carrageenan gels prepared with various carrageenan concentrations in pure water were completely dried and then swelled in water vapor. Steady state fluorescence measurements were performed using a spectrometer equipped with temperature controller. Pyranine was embedded in kappa-carrageenan gels as a fluorescence probe during gel preparation. The fluorescence intensity I increased exponentially as swelling time is increased for all gel samples. The increase in I was modelled using ...
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Signatures of phase transitions in nuclei at finite excitation energies
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Publisher and Date:(Amer Inst Physics, 2012)The mean-field approximation predicts pairing and shape phase transitions in nuclei as a function of temperature or excitation energy. However in the finite nucleus the singularities of these phase transitions are smoothed out by quantal and thermal fluctuations. An interesting question is whether signatures of these transitions survive despite the large fluctuations. The shell model Monte Carlo (SMMC) approach enables us to calculate the statistical properties of nuclei beyond the mean-field ...
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Sparsity Preserving Computation for Spectral Projectors
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Publisher and Date:(Amer Inst Physics, 2011)Several areas of applications such as model order reduction preconditioner design and eigenvalue problems for spectral projectors can be found in the literature. In this paper a fast and sparsity preserving approach for computing the spectral projectors is proposed. The suggested approach can be used in both Newton iteration and integral representation based methods. A comparison of the original and the suggested approaches in terms of computation time sparsity preservation and accuracy is presented ...