scholarly journals The surface tension effect on flexoelectric energy harvesting based on isogeometric analysis

Author(s):  
Kaichun Li ◽  
Du Chengbin
Science ◽  
1930 ◽  
Vol 72 (1862) ◽  
pp. 244-245
Author(s):  
Wm. M. Grosvenor

Author(s):  
Auro Ashish Saha ◽  
Sushanta K. Mitra

A three-dimensional numerical simulation of flow in patterned microchannel with alternate layers of hydrophilic and hydrophobic surfaces at the bottom wall is studied here. Surface characteristics of the microchannel are accounted by specifying the contact angle and the surface tension of the fluid. Meniscus profiles with varying amplitude and shapes are obtained under the different specified surface conditions. Flow instability increases as the fluid at the bottom wall traverses alternately from hydrophilic region to hydrophobic region. To understand the surface tension effect of the side walls, a two-dimensional numerical study has also been carried out for the microchannel and the results are compared with three-dimensional simulation. The surface tension effect of the side walls enhances the capillary effect for three-dimensional case.


2021 ◽  
Vol 9 (11) ◽  
pp. 1253
Author(s):  
Yuriy N. Savchenko ◽  
Georgiy Y. Savchenko ◽  
Yuriy A. Semenov

Cavity flow around a wedge with rounded edges was studied, taking into account the surface tension effect and the Brillouin–Villat criterion of cavity detachment. The liquid compressibility and viscosity were ignored. An analytical solution was obtained in parametric form by applying the integral hodograph method. This method gives the possibility of deriving analytical expressions for complex velocity and for potential, both defined in a parameter plane. An expression for the curvature of the cavity boundary was obtained analytically. By using the dynamic boundary condition on the cavity boundary, an integral equation in the velocity modulus was derived. The particular case of zero surface tension is a special case of the solution. The surface tension effect was computed over a wide range of the Weber number for various degrees of cavitation development. Numerical results are presented for the flow configuration, the drag force coefficient, and the position of cavity detachment. It was found that for each radius of the edges, there exists a critical Weber number, below which the iterative solution process fails to converge, so a steady flow solution cannot be computed. This critical Weber number increases as the radius of the edge decreases. As the edge radius tends to zero, the critical Weber number tends to infinity, or a steady cavity flow cannot be computed at any finite Weber number in the case of sharp wedge edges. This shows some limitations of the model based on the Brillouin–Villat criterion of cavity detachment.


Science ◽  
1930 ◽  
Vol 72 (1862) ◽  
pp. 244-245 ◽  
Author(s):  
Wm. M. Grosvenor

Author(s):  
R. Bezirganyan ◽  
P. Mohanty ◽  
A. Zakarian ◽  
B. Li ◽  
S. Sengupta

In this work Cellular Automata (CA) based droplet Spreading Process (SP) has been investigated. The core of the model is represented by CA based SP algorithm which implements one of the major features of fluid flow, i.e., mass conservation. We show that one input parameter (α) is sufficient for this algorithm to handle variety of droplet diameters, splat shapes, and target surfaces that the droplets impact. Further, we demonstrate constructal alternatives for viscosity and surface tension, which are scales of CA grid layers (s) and splat surface curvature (γ), respectively. We show that bigger s prevents the droplet from penetrating deep into the target surface crevices, and further variation of γ results in the desired surface tension effect. Calibration of the model is carried out using scaling relations, namely α = α(Re), where Re is the Reynolds number. Results obtained in this work showed good compliance with the experimental measurements found in the literature as well as the constructal theory of droplet impact geometry.


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