Simulating the frontal instability of lock-exchange density currents with dissipative particle dynamics

2016 ◽  
Vol 30 (17) ◽  
pp. 1650200 ◽  
Author(s):  
Yanggui Li ◽  
Xingguo Geng ◽  
Heping Wang ◽  
Xin Zhuang ◽  
Jie Ouyang
Keyword(s):  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
Small Scale ◽  
Density Currents ◽  
Two Phase ◽  
Flow Phenomena ◽  
Particle Level ◽  
Macroscopic Simulation ◽  
Frontal Instability ◽  
Dpd Simulation

The frontal instability of lock-exchange density currents is numerically investigated using dissipative particle dynamics (DPD) at the mesoscopic particle level. For modeling two-phase flow, the “color” repulsion model is adopted to describe binary fluids according to Rothman–Keller method. The present DPD simulation can reproduce the flow phenomena of lock-exchange density currents, including the lobe-and-cleft instability that appears at the head, as well as the formation of coherent billow structures at the interface behind the head due to the growth of Kelvin–Helmholtz instability. Furthermore, through the DPD simulation, some small-scale characteristics can be observed, which are difficult to be captured in macroscopic simulation and experiment.

scholarly journals Dissipative particle dynamics simulation study of poly(2-oxazoline)-based multicompartment micelle nanoreactor

2016 ◽  
Vol 18 (8) ◽  
pp. 6284-6290 ◽  
Author(s):  
Byeong Jae Chun ◽  
Christina Clare Fisher ◽  
Seung Soon Jang
Keyword(s):  
Internal Structure ◽  
Simulation Study ◽  
Dissipative Particle Dynamics ◽  
Simulation Method ◽  
Particle Dynamics ◽  
Dynamics Simulation ◽  
Multicompartment Micelles ◽  
Dissipative Particle Dynamics Simulation ◽  
Dpd Simulation

We investigate multicompartment micelles for nanoreactor applications, using the DPD simulation method to characterize the internal structure and the distribution of the reactant.

Simulation of Dripping Using Dissipative Particle Dynamics

2010 ◽  
Author(s):  
Sorush Khajepor ◽  
Meysam Joulaian ◽  
Ahmadreza Pishevar ◽  
Yaser Afshar
Keyword(s):  
Dissipative Particle Dynamics ◽  
Thermal Fluctuations ◽  
Particle Dynamics ◽  
Fluid Density ◽  
Mesoscopic Simulation ◽  
Wall Boundary Condition ◽  
Wide Range ◽  
Breakup Time ◽  
Dpd Simulation ◽  
Good Agreement

Dissipative Particle Dynamics (DPD) is a mesoscopic simulation approach used in wide range of applications and length scales. In this paper, a DPD simulation is carried out to study dripping flow from a nozzle. The results of this study are used to answer this question that whether DPD is capable of simulating the free surface fluid on all different scales. A novel wall boundary condition is developed for the nozzle surface that controls its penetrability, near wall fluid density oscillations and the fluid slip close to the wall. We also utilize a new method to capture the real-time instantaneous geometry of the drop. The obtained results are in good agreement with the macroscopic experiment except near the breakup time, when the fluid thread that connects the primitive drop to the nozzle, becomes tenuous. At this point, the DPD simulation can be justified by thermal length of DPD fluid and the finest accuracy of the simulation that is the radius of a particle. We finally conclude that in spite of the fact that DPD can be used potentially for simulating flow on different scales, it is restricted to the nanoscale problems, due to the surface thermal fluctuations.

DISSIPATIVE PARTICLE DYNAMICS: INTRODUCTION, METHODOLOGY AND COMPLEX FLUID APPLICATIONS — A REVIEW

2009 ◽  
Vol 01 (04) ◽  
pp. 737-763 ◽  
Author(s):  
E. MOEENDARBARY ◽  
T. Y. NG ◽  
M. ZANGENEH
Keyword(s):  
High Performance ◽  
Dissipative Particle Dynamics ◽  
Coarse Graining ◽  
Particle Dynamics ◽  
Hydrodynamic Behavior ◽  
Computational Speed ◽  
Speed Up ◽  
Complex Fluid ◽  
Performance Computing ◽  
Dpd Simulation

The dissipative particle dynamics (DPD) technique is a relatively new mesoscale technique which was initially developed to simulate hydrodynamic behavior in mesoscopic complex fluids. It is essentially a particle technique in which molecules are clustered into the said particles, and this coarse graining is a very important aspect of the DPD as it allows significant computational speed-up. This increased computational efficiency, coupled with the recent advent of high performance computing, has subsequently enabled researchers to numerically study a host of complex fluid applications at a refined level. In this review, we trace the developments of various important aspects of the DPD methodology since it was first proposed in the in the early 1990's. In addition, we review notable published works which employed DPD simulation for complex fluid applications.

ICCM2015(Paper ID:1148): DPD Simulation of the Movement and Deformation of Bioconcave Cells

2016 ◽  
Vol 13 (04) ◽  
pp. 1641003
Author(s):  
L. W. Zhou ◽  
Yu-Qian Zhang ◽  
Xiao-Long Deng ◽  
M. B. Liu
Keyword(s):  
Red Blood Cells ◽  
Poiseuille Flow ◽  
Blood Cells ◽  
Shear Flows ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
Experimental Results ◽  
Shape Evolution ◽  
Movement And Deformation ◽  
Dpd Simulation

This paper presents a dissipative particle dynamics (DPDs) method for investigating the movement and deformation of biconcave shape red blood cells (RBCs) with the worm-like chain (WLC) bead spring. First, the stretching of a RBC is modeled and the obtained shape evolution of the cell agrees well with experimental results. Second, the movement and deformation of a RBC in shear flows are investigated and three typical modes (tumbling, intermittent and tank-treading) are observed. Lastly, an illustrating example of multi-RBCs in Poiseuille flow in a tube is simulated. We conclude that the presented DPD method with WLC spring can effectively model the movement and deformation of bioconcave cells.

pH-Induced evolution of surface patterns in micelles assembled from dirhamnolipids: dissipative particle dynamics simulation

2018 ◽  
Vol 20 (14) ◽  
pp. 9460-9470 ◽  
Author(s):  
Jianchang Xu ◽  
Shuangqing Sun ◽  
Zhikun Wang ◽  
Shiyuan Peng ◽  
Songqing Hu ◽  
...  
Keyword(s):  
Dissipative Particle Dynamics ◽  
Influence Factors ◽  
Particle Dynamics ◽  
Dynamics Simulation ◽  
Morphological Transition ◽  
Effect Of Ph ◽  
Surface Patterns ◽  
Dissipative Particle Dynamics Simulation ◽  
Dpd Simulation

Dissipative particle dynamics (DPD) simulation is used to study the effect of pH on the morphological transition in micelles assembled from dirhamnolipids (diRLs), and analyze the pH-driven mechanism and influence factors of micellar surface patterns.

scholarly journals Effects of Repulsion Parameter and Chain Length of Homopolymers on Interfacial Properties of An/Ax/2BxAx/2/Bm Blends: A DPD Simulation Study

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2333
Author(s):  
Dongmei Liu ◽  
Kai Gong ◽  
Ye Lin ◽  
Huifeng Bo ◽  
Tao Liu ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Chain Length ◽  
Triblock Copolymer ◽  
Triblock Copolymers ◽  
Dissipative Particle Dynamics ◽  
Interfacial Properties ◽  
Particle Dynamics ◽  
Ternary Blends ◽  
Polymeric Blends ◽  
Dpd Simulation

We explored the effects of the repulsion parameter (aAB) and chain length (NHA or NHB) of homopolymers on the interfacial properties of An/Ax/2BxAx/2/Bm ternary polymeric blends using dissipative particle dynamics (DPD) simulations. Our simulations show that: (i) The ternary blends exhibit the significant segregation at the repulsion parameter (aAB = 40). (ii) Both the interfacial tension and the density of triblock copolymer at the center of the interface increase to a plateau with increasing the homopolymer chain length, which indicates that the triblock copolymers with shorter chain length exhibit better performance as the compatibilizers for stabilizing the blends. (iii) For the case of NHA = 4 (chain length of homopolymers An) and NHB (chain length of homopolymers Bm) ranging from 16 to 64, the blends exhibit larger interfacial widths with a weakened correlation between bead An and Bm of homopolymers, which indicates that the triblock copolymer compatibilizers (Ax/2BxAx/2) show better performance in reducing the interfacial tension. The effectiveness of triblock copolymer compatibilizers is, thus, controlled by the regulation of repulsion parameters and the homopolymer chain length. This work raises important considerations concerning the use of the triblock copolymer as compatibilizers in the immiscible homopolymer blend systems.

MATCHING MACROSCOPIC PROPERTIES OF BINARY FLUIDS TO THE INTERACTIONS OF DISSIPATIVE PARTICLE DYNAMICS

2000 ◽  
Vol 11 (01) ◽  
pp. 1-25 ◽  
Author(s):  
WITOLD DZWINEL ◽  
DAVID A. YUEN
Keyword(s):  
Phase Separation ◽  
Sound Velocity ◽  
Dissipative Particle Dynamics ◽  
Phase Interface ◽  
Particle Dynamics ◽  
Scaling Factor ◽  
Domain Growth ◽  
Binary Fluids ◽  
Two Phase ◽  
Macroscopic Properties

We investigate the role played by conservative forces in dissipative particle dynamics (DPD) simulation of single-component and binary fluids. We employ equations from kinetic theory for matching the coefficients of DPD interparticle force to the macroscopic properties of fluid such as: density, temperature, diffusion coefficient, kinematic viscosity and sound velocity. The sound velocity c is coupled with scaling factor π1 of conservative component of the DPD collision operator. Its value sets up an upper limit on the mass S of a single particle in DPD fluid. The Kirkwood–Alder fluid–solid transition is observed for a sufficiently large S. We emphasize the role of the scaling factor π12 for particles of different types in simulating phase separation in binary fluids. The temporal growth of average domain size R(t) in the phase separation process depends on the value of immiscibility coefficient Δ = π12 - π1. For small immiscibility, R (t) ∝ tβ, where β ≈ 1/2 for R (t) < R H and β ≈ 2/3 for R (t) > R H , R H is the hydrodynamic length. Finally, both phases separate out completely. For larger immiscibility, R(t) increases exponentially at the beginning of simulation, while finally the domain growth process becomes marginal. We also observe the creation of emulsion-like structures. This effect results from an increase of the surface tension on the two-phase interface along with increasing immiscibility.

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