scholarly journals Equilibrium Orientation and Adsorption of an Ellipsoidal Janus Particle at a Fluid–Fluid Interface

2020 ◽  
Vol 4 (4) ◽  
pp. 55
Author(s):  
Florian Günther ◽  
Qingguang Xie ◽  
Jens Harting
Keyword(s):  
Free Energy ◽  
Lattice Boltzmann ◽  
Adsorption Process ◽  
Particle Surface ◽  
Fluid Interface ◽  
Janus Particle ◽  
Energy Models ◽  
Lattice Boltzmann Simulations ◽  
Theoretical Predictions ◽  
Particle Aspect Ratio

We investigate the equilibrium orientation and adsorption process of a single, ellipsoidal Janus particle at a fluid–fluid interface. The particle surface comprises equally sized parts that are hydrophobic or hydrophilic. We present free energy models to predict the equilibrium orientation and compare the theoretical predictions with lattice Boltzmann simulations. We find that the deformation of the fluid interface strongly influences the equilibrium orientation of the Janus ellipsoid. The adsorption process of the Janus ellipsoid can lead to different final orientations determined by the interplay of particle aspect ratio and particle wettablity contrast.

scholarly journals Particle-resolved lattice Boltzmann simulations of 3-dimensional active turbulence

Soft Matter ◽  
2019 ◽  
Vol 15 (39) ◽  
pp. 7747-7756 ◽  
Author(s):  
Dóra Bárdfalvy ◽  
Henrik Nordanger ◽  
Cesare Nardini ◽  
Alexander Morozov ◽  
Joakim Stenhammar
Keyword(s):  
Lattice Boltzmann ◽  
Large Scale ◽  
3 Dimensional ◽  
Lattice Boltzmann Simulations ◽  
Theoretical Predictions ◽  
Active Turbulence ◽  
Swimming Bacteria

The dynamics of active turbulence in a suspension of swimming bacteria is characterised using large-scale lattice Boltzmann simulations of model microswimmers and compared to theoretical predictions.

Lattice-Boltzmann Simulations of Complex Fluids

1997 ◽  
Vol 08 (04) ◽  
pp. 783-792 ◽  
Author(s):  
G. Gonnella ◽  
E. Orlandini ◽  
J. M. Yeomans
Keyword(s):  
Free Energy ◽  
Fluid Flow ◽  
Phase Separation ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Positive Curvature ◽  
Navier Stokes ◽  
Two Phase ◽  
Lattice Boltzmann Simulation ◽  
Lattice Boltzmann Simulations

We show that by including thermodynamic functions derived from a chosen free energy in a lattice-Boltzmann simulation of fluid flow it is possible to ensure that the fluid relaxes to a well-defined equlilibrium corresponding to the minimum of the input free energy. Two examples are given of phase separation in a binary fluid: bulk two-phase coexistence and a lamellar phase stabilised by a competition between negative surface tension and positive curvature energy. The lattice-Boltzmann framework simulates the Navier–Stokes equations of fluid flow and hence allows investigation of the effects of hydrodynamics on the kinetics of phase separation and on the rheology of the ordered structures.

Modeling Elastic Walls in Lattice Boltzmann Simulations of Arterial Blood Flow

2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer
Keyword(s):  
Blood Flow ◽  
Lattice Boltzmann ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Lattice Boltzmann Simulations ◽  
Elastic Walls

scholarly journals A thermodynamic approach to rate-type models in deformable ferroelectrics

2020 ◽  
Author(s):  
Claudio Giorgi ◽  
Angelo Morro
Keyword(s):  
Free Energy ◽  
Electric Field ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Energy Models ◽  
Polarization Electric Field ◽  
Field Plane ◽  
Vector Valued ◽  
Rate Type ◽  
Hysteretic Properties

AbstractThe purpose of the paper is to establish vector-valued rate-type models for the hysteretic properties in deformable ferroelectrics within the framework of continuum thermodynamics. Unlike electroelasticity and piezoelectricity, in ferroelectricity both the polarization and the electric field are simultaneously independent variables so that the constitutive functions depend on both. This viewpoint is naturally related to the fact that an hysteresis loop is a closed curve in the polarization–electric field plane. For the sake of generality, the deformation of the material and the dependence on the temperature are allowed to occur. The constitutive functions are required to be consistent with the principle of objectivity and the second law of thermodynamics. Objectivity implies that the constitutive equations are form invariant within the set of Euclidean frames. Among other results, the second law requires a general property on the relation between the polarization and the electric field via a differential equation. This equation shows a dependence fully characterized by two quantities: the free energy and a function which is related to the dissipative character of the hysteresis. As a consequence, different hysteresis models may have the same free energy. Models compatible with thermodynamics are then determined by appropriate selections of the free energy and of the dissipative part. Correspondingly, major and minor hysteretic loops are plotted.

scholarly journals Research on Human Erythrocyte’s Threshold Free Energy for Hemolysis and Damage from Coupling Effect of Shear and Impact Based on Immersed Boundary-Lattice Boltzmann Method

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Zhong Yun ◽  
Chuang Xiang ◽  
Liang Wang
Keyword(s):  
Free Energy ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Coupling Effect ◽  
Threshold Value ◽  
Blood Pump ◽  
Immersed Boundary ◽  
Threshold Limit ◽  
Spring Network Model ◽  
Boltzmann Method

Researches on the principle of human red blood cell’s (RBC) injuring and judgment basis play an important role in decreasing the hemolysis in a blood pump. In the current study, the judgment of hemolysis in a blood pump study was through some experiment data and empirical formula. The paper forms a criterion of RBC’s mechanical injury in the aspect of RBC’s free energy. First, the paper introduces the nonlinear spring network model of RBC in the frame of immersed boundary-lattice Boltzmann method (IB-LBM). Then, the shape, free energy, and time needed for erythrocyte to be shorn in different shear flow and impacted in different impact flow are simulated. Combining existing research on RBC’s threshold limit for hemolysis in shear and impact flow with this paper’s, the RBC’s free energy of the threshold limit for hemolysis is found to be 3.46 × 10 − 15  J. The threshold impact velocity of RBC for hemolysis is 8.68 m/s. The threshold value of RBC can be used for judgment of RBC’s damage when the RBC is having a complicated flow of blood pumps such as coupling effect of shear and impact flow. According to the change law of RBC’s free energy in the process of being shorn and impacted, this paper proposed a judging criterion for hemolysis when the RBC is under the coupling effect of shear and impact based on the increased free energy of RBC.

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