Search results for "suspension"
showing 10 items of 262 documents
Parallelization of a Lattice Boltzmann Suspension Flow Solver
2002
We have applied a parallel Lattice Boltzmann method to solve the behaviour of the suspension flow. The complex behaviour of the suspension flow cannot be solved by analytical methods, so simulations are the only way to study it. Usually the size of an interesting problem is so big that calculation time on one processor is too long, and this can be solved by parallel program. We have written a parallel suspension flow solver and tested it on massive parallel computers. The measured performance of our program show that the parallelization of suspension particles was successful. We also show that over one million particles can be simulated.
Revealing Magnetite Nanoparticles Aggregation Dynamics – A SLS and DLS Study
2010
\(\mathrm{Fe}_{3}\mathrm{O}_{4}\) nanoparticles in aqueous suspensions are not stable but aggregate, tremendously changing the rheological properties of the nanofluid. Modified version of both the Static Light Scattering (SLS) setup and of Dynamic Light Scattering (DLS) setup experiment were used to monitor \(\mathrm{Fe}_{3}\mathrm{O}_{4}\) nanoparticle aggregation in aqueous diluted suspension. The experiments are described in detail and the variation of the average aggregate diameter in time is presented in this work.
The rheology of three-phase suspensions at low bubble capillary number
2015
We develop a model for the rheology of a three-phase suspension of bubbles and particles in a Newtonian liquid undergoing steady flow. We adopt an 'effective-medium' approach in which the bubbly liquid is treated as a continuous medium which suspends the particles. The resulting three-phase model combines separate two-phase models for bubble suspension rheology and particle suspension rheology, which are taken from the literature. The model is validated against new experimental data for three-phase suspensions of bubbles and spherical particles, collected in the low bubble capillary number regime. Good agreement is found across the experimental range of particle volume fraction ([Formula: s…
The Atmospheric Aerosol and Trace Gases
2010
From Chapter 6, it is evident that an understanding of the cloud forming processes in the atmosphere requires knowledge of the physical and chemical characteristics of the atmospheric aerosol. In dicussing this gaseous suspension of solid and liquid particles, it is customary to include all gases except water vapor, and all solid and liquid particles except hydrometeors, i.e., cloud and raindrops, and ice particles.
Consistence of the Mean Field Description of Charged Colloidal Crystal Properties
2006
The Debye-Huckel-Potential in combination with an effective or renormalized charge is a widely and often successfully used concept to describe the interaction in charged colloidal model systems and the resulting suspension properties. In particular the phase behaviour can be described in dependence of the parameters particle number density, salt concentration and effective charge. We performed simultaneous measurements of the phase behaviour, the shear modulus and the low frequency conductivity of deionised aqueous suspensions of highly charged colloidal spheres. From the shear modulus the interaction potential at the nearest neighbour distance in terms of a Debye-Huckel potential can be de…
Magnetorheology: Fluids, Structures and Rheology
2002
Magnetorheological suspensions are complex fluids which show a transition from a liquid behavior to a solid one upon application of a magnetic field. This transition is due to the the attractive dipolar forces between the particles which have been magnetized by the applied field. The formation of a network of particles or aggregates throughout the suspension is the basic phenomena which is responsible for the strength of the solid phase. In this paper we shall give an overview on the fluids and their properties and we shall especially emphasize the interplay between magnetic forces which are responsible for the gelling of the suspension and on the other hand of hydrodynamic and thermal forc…
Colloidal layers in magnetic fields and under shear flow
2005
The behaviour of colloidal mono- and bilayers in external magnetic fields and under shear is discussed and recent progress is summarized. Superparamagnetic colloidal particles form monolayers when they are confined to a air–water interface in a hanging water droplet. An external magnetic field allows us to tune the strength of the mutual dipole–dipole interaction between the colloids and the anisotropy of the interaction can be controlled by the tilt angle of the magnetic field relative to the surface normal of the air–water interface. For sufficiently large magnetic field strength crystalline monolayers are found. The role of fluctuations in these two-dimensional crystals is discussed. Fur…
Spectral WENO schemes with Adaptive Mesh Refinement for models of polydisperse sedimentation
2012
The sedimentation of a polydisperse suspension with particles belonging to N size classes (species) can be described by a system of N nonlinear, strongly coupled scalar first-order conservation laws. Its solutions usually exhibit kinematic shocks separating areas of different composition. Based on the so-called secular equation [J. Anderson, Lin. Alg. Appl. 246, 49–70 (1996)], which provides access to the spectral decomposition of the Jacobian of the flux vector for this class of models, Burger et al. [J. Comput. Phys. 230, 2322–2344 (2011)] proposed a spectral weighted essentially non-oscillatory (WENO) scheme for the numerical solution of the model. It is demonstrated that the efficiency …
Matlab/Simulink-Based Modeling for Industrial Electric Vehicle
2023
The land transport sector has passed through multiple phases of evolution in design, development, and manufacturing of vehicles. In particular, the construction site continues to progress towards the autonomous vehicles (also called self-driving), which were one of its big trends and have become a hot topic in the industrial and academic world. By now, with this new technology of autonomous driving, we can ensure safety by reducing the number of road accidents, also the environmental impact and energy consumption is lessened. The modeling and simulation phases had become a mandatory step to design, characterize and simulate vehicle dynamics while reducing the cost of development. As they pr…
An Adaptive Metamodel-Based Optimization Approach for Vehicle Suspension System Design
2014
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/965157 The performance index of a suspension system is a function of the maximum and minimum values over the parameter interval. Thus metamodel-based techniques can be used for designing suspension system hardpoints locations. In this study, an adaptive metamodel-based optimization approach is used to find the proper locations of the hardpoints, with the objectives considering the kinematic performance of the suspension. The adaptive optimization method helps to find the optimum locations of the hardpoints efficiently as it may be unachie…