1,723,411 research outputs found
Multirange multi-relaxation time Shan–Chen model with extended equilibrium
No full textAbstractThe work presents simulations with the multirange Shan–Chen model developed by Sbragaglia et al. (2007) [18], which improved the Shan–Chen model for the proper surface tension term. Also, by introducing the matrix collision operator and extended equilibrium density distribution function, the density ratio is increased from 100 to 160. The Multi-Relaxation Time (MRT) method attracted the attention of researchers due to several advantages, such as better stability, simulations with Prandtl number different from unity, and possibilities to improve the accuracy of the scheme compared with BGK Single Time Relaxation model. Our recent results have shown that the combination of MRT methods with multiphase flow models can improve the achievable gas–liquid density ratio
Scalar field inflation and Shan-Chen fluid models
Full text linkA scalar field equivalent to a non-ideal "dark energy fluid" obeying a Shan-Chen-like equation of state is used as the background source of a flat Friedmann-Robertson-Walker cosmological spacetime to describe the inflationary epoch of our universe. Within the slow-roll approximation, a number of interesting features are presented, including the possibility to fulfill current observational constraints as well as a graceful exit mechanism from the inflationary epoch
Scalar field inflation and Shan-Chen fluid models
No full textA scalar field equivalent to a nonideal “dark energy fluid” obeying a Shan-Chen-like equation of state is used as the background source of a flat Friedmann-Robertson-Walker cosmological spacetime to describe the inflationary epoch of our Universe. Within the slow-roll approximation, a number of interesting features are presented, including the possibility to fulfill current observational constraints as well as a graceful exit mechanism from the inflationary epoch.</p
Plasticity and agglomeration in coal pyrolysis
Full text linkThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1986.MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE.Bibliography: leaves 202-205.by William Shan-chen Fong.Ph.D
Supplemental Material - Assessing the Psychometric Properties of STEAM Competence in Primary School Students: A Construct Measurement Study
No full textSupplemental Material for Assessing the Psychometric Properties of STEAM Competence in Primary School Students: A Construct Measurement Study by Shan Chen and Yuanzhao Ding in Journal of Psychoeducational Assessment</p
Relevance of capillary interfaces simulation with the Shan–Chen multiphase LB model
No full textInternational audienceThis paper presents a numerical study of capillary interfaces using the Single Component Multi-Phase Shan-Chen model, which is based on the lattice Boltzmann method. Despite the simplicity of the model, it has been shown to be effective and the present study aims to test its ability to correctly reproduce the physics of multiphase systems. To this end, several benchmark simulations were carried out in the configurations of a drop on a flat wall and then on a spherical surface to characterize the wetting behavior and relate explicitly the contact angle to model parameters. In addition, the capillary forces induced by a liquid bridge between two spherical particles were numerically calculated. We show that the results obtained are in agreement with experimental and theoretical results from the literature. The model is thus accurate in addressing the wetting behavior and capillary interfaces in unsaturated granular soils despite the fact that surface tension and contact angles are not explicit parameters of the model. To this respect, explicit relationships with Shan-Chen parameters are provided
Combining neutral scalar and isothermal Shan-Chen lattice Boltzmann method to simulate droplet placement on a wall in isothermal and non-isothermal states
No full textRahmani, Amin/0009-0004-6746-4747; Jumaah, Dheyaa/0000-0001-7259-3392Background: In the current article, two-phase thermal fluxes are created by combining the thermal model of the neutral scalar model with the two-phase Shan-Chen model of the lattice Boltzmann method (LBM). Methods: The different intermolecular powers for the isothermal Shan-Chen model show how a droplet would be placed on a wall. By raising the droplet intermolecular power parameter, the surface area increases and becomes wet. Next, the isothermal Shan-Chen method and the neutral scalar method are combined to investigate multiphase thermal problems. The droplet placement on the hot wall is therefore done at relatively high Rayleigh numbers. By raising the Rayleigh number, the isothermal lines within the droplet's interior gradually become less ascending and less descending until they eventually achieve a uniform state when it is placed against a hot wall. Additionally, the channel's Rayleigh-Benard convective heat transfer is enhanced by increasing the Rayleigh number. Significant findings: Natural convection in the enclosures can be used in solar collectors. As the Rayleigh number increases, the average Nusselt number (Nuavg) rises as would be expected. The results demonstrate that LBM is a practical method for simulating multi-phase thermal flows
Wormholes supported by phantom energy from Shan–Chen cosmological fluids
No full textIn the present paper, the exact solutions of spherically symmetrical Einstein field equations describing wormholes supported by phantom energy that violates the null energy condition from Shan–Chen background fluid are obtained. We have considered the important case of the model parameter , which corresponds to the “saturation effect”, and this regime corresponds to an effective form of “asymptotic freedom” for the fluids, but occurring at cosmological rather than subnuclear scales. Then we investigate the allowed range for the values of the model parameters g and when the spacetime metrics describe wormholes and discuss the possible singularities of the solutions, finding that the obtained spacetimes are geodesically complete. Furthermore, we construct two traversable wormholes through matching our obtained interior solutions to the exterior Schwarzschild solutions and analyze the traversablities of the wormholes. Finally, we consider the case of anisotropic pressure and discover that the transverse pressure also crosses the phantom divide with the growth of the wormhole dimension, and it tends to be the same as the radial pressure with the growth of the wormhole radius
Late-time evolution of cosmological models with fluids obeying a Shan-Chen-like equation of state
No full textClassical as well as quantum features of the late-time evolution of cosmological models with fluids
obeying a Shan-Chen-like equation of state are studied. The latter is of the type p=weff(ρ)ρ and has been
used in previous works to describe, e.g., a possible scenario for the growth of the dark-energy content of the
present Universe. At the classical level, the fluid dynamics in a spatially flat Friedmann-Robertson-Walker
background implies the existence of two possible equilibrium solutions depending on the model parameters
associated with (asymptotic) finite pressure and energy density. We show that no future cosmological
singularity is developed during the evolution for this specific model. The corresponding quantum effects in
the late-time behavior of the system are also investigated within the framework of quantum geometrodynamics,
i.e., by solving the (minisuperspace) Wheeler-DeWitt equation in the Born-Oppenheimer
approximation, constructing wave packets and analyzing their behavior
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