Symmetric Boundary Condition for the MPS Method with Surface Tension Model

2021 ◽  
pp. 105283
Author(s):  
Qixin Liu ◽  
Zhongguo Sun ◽  
Yijie Sun ◽  
Kai Zhang ◽  
Guang Xi
Keyword(s):  
Boundary Condition ◽  
Surface Tension ◽  
Mps Method ◽  
Symmetric Boundary Condition ◽  
Surface Tension Model

Numerical Investigation on Droplet Wetting Effect With the MPS Method

2014 ◽  
Author(s):  
Xiao Chen ◽  
Zhongguo Sun ◽  
Guang Xi
Keyword(s):  
Surface Tension ◽  
Large Deformation ◽  
Incompressible Flows ◽  
Potential Method ◽  
Surface Flow ◽  
Shape Distortion ◽  
Energy Principle ◽  
Mps Method ◽  
Interparticle Potential ◽  
Surface Tension Model

The wetting effect of droplets is widely encountered in various industrial processes, such as mist cooling, dropwise condensation and electro wetting. Since these complicated processes are mostly free surface flow with large deformation, the moving particle semi-implicit (MPS) method is used for simulation in this study. The MPS method is a kind of Lagrangian meshless method and has advantages in simulating incompressible flows with large deformation. In order to simulate the surface tensions and interface tensions of different substances, the interparticle potential method was used in this paper. However, under the conventional surface tension model, the stable and well-formed droplets are hard to simulate due to the particle clustering and the shape distortion. In this paper, the parameters of interparticle potential model were studied and optimized to resolve these problems. Additionally, with the improved surface tension model, the oscillation and deformation process of a square droplet was simulated, and the result of which agreed well with the theoretical results. A circular relative error was defined to assess the final stable, well-formed droplet. Besides, the shrinkage and wetting effect, due to the surface tension, between multi-substances (gas-liquid, solid-liquid or liquid-liquid) were examined and analyzed. The calculated wetting angle and wetting area were extracted and agreed with the analytical ones. The wetting relationships under different interface tensions agreed with the lowest energy principle. The droplets with different substances would wet each other in a certain order due to the differences between their interface tensions. The self-assembly processing in Micro-Electro-Mechanical Systems (MEMS) was simulated and the component finally moved to directly above the adhesive area.

scholarly journals Symmetric Boundary Condition for Laplacian on Net of Regular Hexagons

2017 ◽  
Vol 9 (3) ◽  
pp. 46
Author(s):  
Daniel Lee
Keyword(s):  
Boundary Condition ◽  
Matrix Theory ◽  
Three Dimensional ◽  
Cardiac Tissues ◽  
Energy Product ◽  
Symmetric Boundary Condition ◽  
Almost All ◽  
Wave Phenomena ◽  
Dimensional Cell ◽  
Theory Series

Hexagonal grid methods are found useful in many research works, including numerical modeling in spherical coordinates, in atmospheric and ocean models, and simulation of electrical wave phenomena in cardiac tissues. Almost all of these used standard Laplacian and mostly on one configuration of regular hexagons. In this work, discrete symmetric boundary condition and energy product for anisotropic Laplacian are investigated firstly on general net of regular hexagons, and then generalized to its most extent in two- or three-dimensional cell-center finite difference applications up to the usage of symmetric stencil in central differences. For analysis of Laplacian related applications, this provides with an approach in addition to the M-matrix theory, series method, functional interpolations and Fourier vectors.

Numerical Simulation of Three-Layer-Liquid Sloshing by Multiphase MPS Method

2018 ◽  
Author(s):  
Xiao Wen ◽  
Decheng Wan
Keyword(s):  
Present Method ◽  
Single Phase ◽  
Particle Interaction ◽  
Liquid Sloshing ◽  
Mps Method ◽  
Basic Particle ◽  
Viscosity Fluid ◽  
Surface Tension Model ◽  
Single Set ◽  
Good Agreement

In the present study, three-layer-liquid sloshing in a rigid tank is simulated based on the newly developed multiphase MPS method. Firstly, the multiphase MPS method is introduced in detail, including the basic particle interaction models and the special interface treatments employed to extend single phase MPS solver to multiphase flows simulations. The new multiphase MPS method treats the multifluid system as the multi-density and multi-viscosity fluid, thus only a single set of equations needs to be solved for all phases. Besides, extra density smoothing technique, interparticle viscosity model and surface tension model are included in the present method for interface particles. The new multiphase MPS method is then applied to simulate three-layer-liquid sloshing in a rigid tank and verified through comparison with the experiment conducted by Molin et al. [1]. The predicted motion of interfaces by the present method shows a good agreement with the experimental data and other numerical results.

Displacement and Blocking Force Modeling for Piezoelectric Uniflex Microactuators

2008 ◽  
Author(s):  
Hareesh K. R. Kommepalli ◽  
Han G. Yu ◽  
Srinivas A. Tadigadapa ◽  
Christopher D. Rahn ◽  
Susan Trolier-McKinstry ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Applied Voltage ◽  
Piezoelectric Actuators ◽  
Small Strain ◽  
Amplitude Response ◽  
Rf Switches ◽  
Symmetric Boundary Condition ◽  
Force Modeling ◽  
Controlled Motion ◽  
Parameter Ranges

Microactuators provide controlled motion and force for applications ranging from RF switches to rate gyros. Large amplitude response in piezoelectric actuators requires amplification of their small strain. This paper studies a uniflex microactuator that combines the strain amplification mechanisms of a unimorph and flexural motion to produce large displacement and blocking force. An analytical model is developed with three connected beams and a reflective symmetric boundary condition that predicts actuator displacement and blocking force as a function of the applied voltage. The model shows that the uniflex design requires appropriate parameter ranges, especially the clearance between the unimorph and aluminum cap, to ensure that both the unimorph and flexural amplification effects are realized. With a weakened joint at the unimorph/cap interface, the model accurately predicts the displacement and blocking force of four actuators.

A new algorithm for surface tension model in moving particle methods

2007 ◽  
Vol 55 (3) ◽  
pp. 225-240 ◽  
Author(s):  
Shuai Zhang ◽  
Koji Morita ◽  
Kenji Fukuda ◽  
Noriyuki Shirakawa
Keyword(s):  
Surface Tension ◽  
Particle Methods ◽  
Moving Particle ◽  
Surface Tension Model

Spreading-Droplet Simulation With Surface Tension Model Using Inter-Particle Force in Particle Method

2013 ◽  
Author(s):  
Eiji Ishii ◽  
Taisuke Sugii
Keyword(s):  
Surface Tension ◽  
Contact Angle ◽  
Dynamic Contact Angle ◽  
Particle Method ◽  
Dynamic Contact ◽  
Contact Angles ◽  
Particle Methods ◽  
Static Contact ◽  
Particle Force ◽  
Surface Tension Model

Predicting the spreading behavior of droplets on a wall is important for designing micro/nano devices used for reagent dispensation in micro-electro-mechanical systems, printing processes of ink-jet printers, and condensation of droplets on a wall during spray forming in atomizers. Particle methods are useful for simulating the behavior of many droplets generated by micro/nano devices in practical computational time; the motion of each droplet is simulated using a group of particles, and no particles are assigned in the gas region if interactions between the droplets and gas are weak. Furthermore, liquid-gas interfaces obtained from the particle method remain sharp by using the Lagrangian description. However, conventional surface tension models used in the particle methods are used for predicting the static contact angle at a three-phase interface, not for predicting the dynamic contact angle. The dynamic contact angle defines the shape of a spreading droplet on a wall. We previously developed a surface tension model using inter-particle force in the particle method; the static contact angle of droplets on the wall was verified at various contact angles, and the heights of droplets agreed well with those obtained theoretically. In this study, we applied our surface tension model to the simulation of a spreading droplet on a wall. The simulated dynamic contact angles for some Weber numbers were compared with those measured by Šikalo et al, and they agreed well. Our surface tension model was useful for simulating droplet motion under static and dynamic conditions.

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