Wyniki wyszukiwania - BazTech

1

Modelling of erythrocyte behaviour in blood capillaries by structural model combined with Lattice-Boltzmann approach

Przekop R., Majewski I., Moskal A.

Chemical and Process Engineering

|

2018

|

Vol. 39, nr 4

411–-426

EN

A microstructural model of Red Blood Cell (RBC) behaviour was proposed. The erythrocyte is treated as a viscoelastic object, which is denoted by a network of virtual particles connected by elastic springs and dampers (Kelvin-Voigt model). The RBC is submerged in plasma modelled by lattice Boltzmann fluid. Fluid – structure interactions are taken into account. The simulations of RBC behaviour during flow in a microchannel and wall impact were performed. The results of RBC deformation during the flow are in good agreement with experimental data. The calculations of erythrocyte disaggregation from the capillary surface show the impact of RBC structure stiffness on the process.

2

Estimation of Filtration Efficiency – from Simple Correlations to Digital Fluid Dynamics

Przekop R.

Chemical and Process Engineering

|

2017

|

Vol. 38, nr 1

31--50

EN

Aerosol filtration in fibrous filters is one of the principal methods of accurate removal of particulate matter from a stream of gas. The classical theory of depth filtration of aerosol particles in fibrous structures is based on the assumption of existing single fibre efficiency, which may be used to recalculate the overall efficiency of entire filter. Using “classical theory” of filtration one may introduce some errors, leading finally to a discrepancy between theory and experiment. There are several reasons for inappropriate estimation of the single fibre efficiency: i) neglecting of shortrange interactions, ii) separation of inertial and Brownian effects, ii) perfect adhesion of particles to the fibre, iv) assumption of perfect mixing of aerosol particles in the gas stream, v) assumption of negligible effect of the presence of neighbouring fibres and vi) assumption of perpendicular orientation of homogenous fibres in the filtration structure. Generally speaking, “classical theory” of filtration was used for characterization of the steady - state filtration process (filtration in a clean filter, at the beginning of the process) without deeper investigation of the influence of the nternal structure of the filter on its performance. The aim of this review is to outline and discuss the progress of deep-bed filtration modelling from the use of simple empirical correlations to advanced techniques of Computational Fluid Dynamics and Digital Fluid Dynamics.

3

Dynamics of particle loading in deep-bed filter. Trasport, deposition and reentrainment

Przekop R., Gradoń L.

Chemical and Process Engineering

|

2016

|

Vol. 37, nr 3

405--417

EN

Deep bed filtration is an effective method of submicron and micron particle removal from the fluid stream. There is an extensive body of literature regarding particle deposition in filters, often using the classical continuum approach. However, the approach is not convenient for studying the influence of particle deposition on filter performance (filtration efficiency, pressure drop) when non-steady state boundary conditions have to be introduced. For the purposes of this work the lattice-Boltzmann model describes fluid dynamics, while the solid particle motion is modeled by the Brownian dynamics. For aggregates the effect of their structure on displacement is taken into account. The possibility of particles rebound from the surface of collector or reentrainment of deposits to fluid stream is calculated by energy balanced oscillatory model derived from adhesion theory. The results show the evolution of filtration efficiency and pressure drop of filters with different internal structure described by the size of pores. The size of resuspended aggregates and volume distribution of deposits in filter were also analyzed. The model enables prediction of dynamic filter behavior. It can be a very useful tool for designing filter structures which optimize maximum lifetime with the acceptable values of filtration efficiency and pressure drop.

4

Wykorzystanie metody lattice-Boltzmann do symulacji mikroprzepływów w kanałach układów lab on a chip

Szafran R., Tomczak T.

Inżynieria i Aparatura Chemiczna

|

2013

|

Nr 6

568--569

PL

W pracy zostały przedstawione wyniki badań doświadczalnych i symulacji komputerowych metodą Lattice-Boltzmann przepływów płynów komórkowych w mikrokanałach układu lab-on-a-chip (LOC). Symulacje LBM przeprowadzono dla geometrii 2D (model 2DQ9), co wpłynęło na skrócenie czasu obliczeń, w istotny sposób zwiększając jednak ich błąd, który wahał się w szerokich granicach od 15 do ponad 100%.

EN

Experimental and computer simulation results using the Lattice-Boltzmann method for fluid flows in microchannels of the lab-on-a-chip (LOC) device are presented in the paper. LBM simulations were performed for 2D geometry (2DQ9 model), allowing the shortening of simulation time but signifi¬cantly increasing the calculation error. The calculation error of fluid mean velocity ranged from 15 to over 100%.

5

Modelling drop dynamics on patterned surfaces

Yeomans J.M., Kusumaatmaja H.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2007

|

Vol. 55, nr 2

203-210

EN

We present a mesoscopic model able to capture the physics of drops moving across patterned surfaces. In this model, interfaces appear naturally, and "both chemical and topological patterning ran be incorporated wit h relative ease, making it particularly suitable to study the behaviour of evolving drops. We summarise results on drop dynamics, including drops spreading on a chemically patterned surface, using a hydrophobic grid to alleviate mottle and the transition and dynamics of drops moving across a superhydrophobic surface.

6

Mixing in a stirred vessel. A parallel implementation with lattice Boltzmann coloured particles model

Misci L., Felici M.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

|

2005

|

Vol. 9, No 4

449-459

EN

The main purpose of this paper is to present a new method for the study of single fluid mixing in a stirred vessel. The simulation has been realized with a parallel implementation of the Lattice Boltzmann coloured particles model. The mixing phenomenon is compared with the one derived with a Lagrangian approach.