Effects of Nano-Nozzles Cross-Sectional Geometry on Fluid Flow: Molecular Dynamic Simulation

2017 ◽  
Vol 34 (5) ◽  
pp. 667-678 ◽  
Author(s):  
H. Nowruzi ◽  
H. Ghassemi
Keyword(s):  
Fluid Flow ◽  
Velocity Profile ◽  
Cross Sections ◽  
Md Simulation ◽  
Flow Behavior ◽  
Water Model ◽  
Physical Parameters ◽  
Cross Sectional ◽  
Behavior Characteristics ◽  
Fanning Friction Factor

AbstractNano-nozzles are an essential part of the nano electromechanical systems (NEMS). Cross-sectional geometry of nano-nozzles has a significant role on the fluid flow inside them. So, main purpose of the present study is related to the effects of different symmetrical cross-sections on the fluid flow behavior inside of nano-nozzles. To this accomplishment, five different cross-sectional geometries (equilateral triangle, square, regular hexagon, elliptical and circular) are investigated by using molecular dynamics (MD) simulation. In addition, TIP4P is used for atomistic water model. In order to evaluate the fluid flow behavior, non-dimensional physical parameters such as Fanning friction factor, velocity profile and density number are analyzed. Obtained results are shown that the flow behavior characteristics appreciably depend on the geometry of nano-nozzle's cross-section. Velocity profile and density number for five different cross sections of nano-nozzle at three various measurement gauges are presented and discussed.

Velocity Profile Investigation of FFS Microchannel at Re 100

2014 ◽  
Vol 487 ◽  
pp. 290-293
Author(s):  
Vithyacharan Retnasamy ◽  
Zaliman Sauli ◽  
Steven Taniselass ◽  
Nor Shakirina Nadzri ◽  
Tan Hsio Mei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Velocity Distribution ◽  
Cross Sections ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Step Height ◽  
Forward Facing Step

Recently, microfluidics system has been widely employed in various areas for instance biomedical,pharmaceuticals and cell biological researchdue to its advantages. The flow behavior in microchannels with different cross-sections has been topic in previous studies. In this paper, numerical simulation of fluid flow in Forward Facing Step (FFS) configuration was performed to investigate velocity profile after the step. Reynolds numbers (Re) 100 with different step heights, 1μm and 3μm were used to observe trend occurs in the flow characteristics. The result illustrated an increase of velocity distribution with the increase of the step height.

scholarly journals Investigation Concerning the Fluid Flow in the Mixed-Flow Diffuser

1971 ◽  
Author(s):  
Shinji Honami ◽  
Keizo Tsukagoshi ◽  
Toshimichi Sakai ◽  
Ichiro Watanabe
Keyword(s):  
Boundary Layer ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Pressure Gradients ◽  
Flow Mechanism ◽  
Mixed Flow ◽  
Three Dimensional Flow ◽  
Layer Flow

Velocity profile measurements were performed on the flow in a mixed-flow diffuser with walls having equal cone angles. The aim of the present study is to understand the flow behavior and the relation between the flow patterns and the diffuser losses. The boundary layer flow accompanied by separation on the inner wall and the velocity normal to the diffuser walls were measured in detail to examine the three-dimensional flow behavior in the mixed-flow diffuser. Comparing with the radial diffuser, the mixed-flow diffuser had a more complicated flow mechanism as it had the pressure gradients of transverse and normal directions.

scholarly journals An optimal analysis for Darcy–Forchheimer three-dimensional Williamson nanofluid flow over a stretching surface with convective conditions

2019 ◽  
Vol 11 (3) ◽  
pp. 168781401983351 ◽  
Author(s):  
Abdullah Dawar ◽  
Zahir Shah ◽  
Saeed Islam ◽  
Waris Khan ◽  
Muhammad Idrees
Keyword(s):  
Heat Transfer ◽  
Brownian Motion ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Flow Behavior ◽  
Three Dimensional ◽  
And Brownian Motion ◽  
Homotopy Analysis ◽  
Motion Parameters ◽  
The Impact

The augmented thermal conductivity is significant in betterment of heat transfer behavior of fluids. A number of other physical quantities such as density, viscosity, and specific heat play the key role in fluid flow behavior. Investigators have shown that the nanofluids have not only superior heat conductivity but also have better convective heat transfer capability than the base fluids. In this article, the analysis of three-dimensional Williamson fluid has been carried out under investigation. The fluid flow is taken over a linear porous stretching sheet under the influence of thermal radiation. The transformed system of equations has been solved by homotopy analysis method. The impact of embedded parameters on the fluid flow has shown graphically. The velocity profile in x-direction is decreased with the augmented stretching, Williamson, coefficient of inertia, and porosity parameters. The velocity profile in y-direction is increased with the enlarged stretching parameter, while reduced with the augmented Williamson, coefficient of inertia, and porosity parameters. The temperature profile is increased with the enlarged stretching, radiation, thermophoresis, parameter and Brownian motion parameters, and Biot number while decreased with the increased Prandtl number. The concentration profile is increased with the increased thermophoresis parameter and Biot numbers, while decreased with the enlarged stretching and Brownian motion parameters.

scholarly journals Experiments on Liquid Flow through Non-Circular Micro-Orifices

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 510 ◽  
Author(s):  
Stefano Cassineri ◽  
Andrea Cioncolini ◽  
Liam Smith ◽  
Michele Curioni ◽  
Fabio Scenini
Keyword(s):  
Cross Sections ◽  
Liquid Flow ◽  
Rectangular Cross Section ◽  
Flow Behavior ◽  
Research Area ◽  
Hydraulic Diameter ◽  
Cross Sectional ◽  
Pressurized Water ◽  
Active Research ◽  
Sectional Shape

Microfluidics is an active research area in modern fluid mechanics, with several applications in science and engineering. Despite their importance in microfluidic systems, micro-orifices with non-circular cross-sections have not been extensively investigated. In this study, micro-orifice discharge with single-phase liquid flow was experimentally investigated for seven square and rectangular cross-section micro-orifices with a hydraulic diameter in the range of 326–510 µm. The discharge measurements were carried out in pressurized water (12 MPa) at ambient temperature (298 K) and high temperature (503 K). During the tests, the Reynolds number varied between 5883 and 212,030, significantly extending the range in which data are currently available in the literature on non-circular micro-orifices. The results indicate that the cross-sectional shape of the micro-orifice has little, if any, effect on the hydrodynamic behavior. Thus, existing methods for the prediction of turbulent flow behavior in circular micro-orifices can be used to predict the flow behavior in non-circular micro-orifices, provided that the flow geometry of the non-circular micro-orifice is described using a hydraulic diameter.

scholarly journals Fluid Flow Characterization of Single-Strand Tundish with Flow Modifiers through Physical Water Model (PWM) and CFD Simulation

2021 ◽  
Vol 12 (1) ◽  
pp. 211-221
Keyword(s):  
Fluid Flow ◽  
Residence Time ◽  
Cfd Simulation ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Steel Production ◽  
Single Strand ◽  
Experimental Simulation ◽  
Water Model ◽  
Inclusion Removal

The flow behavior in the continuous casting tundish dominates the quality and cleanliness of steel production. In this research, the single strand tundish's fluid flow behavior with different flow modifiers is investigated through numerical and experimental simulation. The numerical; simulation is performed in ANSYS FLUENT 19.2 (commercial package) and experimental through physical water model technique. The flow behaviors of bare tundish and tundish with three different flow modifiers are investigated. The three different flow modifiers deployed are the dam, baffle, and turbulence inhibiter (TI). Fluid flow performance is examined through residence time distribution (RTD) curves, which are derived from the measurement of the tracer concentration at the outlet. Good agreement between the CFD simulation and physical water model experiments is discovered. The results show there is an improvement in residence time and fluid flow (also improved inclusion removal) after the deployment of flow modifiers. There is a 20% improvement in peak and minimum residence time of RTD curves due to flow modifiers application. It is also discovered that the tundish configuration in this research, the tundish with turbulence inhibiter, provides optimal flow characteristics and eventually intended to promote a better level of inclusion removal.

Computational Modeling of Micro-Fluid Flow in a Tubular Microchannel

2006 ◽  
Vol 505-507 ◽  
pp. 433-438 ◽  
Author(s):  
Chao Ming Lin ◽  
Te Hua Fang ◽  
Win Jin Chang
Keyword(s):  
Fluid Flow ◽  
Cross Section ◽  
Cross Sections ◽  
Governing Equation ◽  
Initial Value Problem ◽  
Computational Models ◽  
Flow Behavior ◽  
Viscous Force ◽  
Initial Value ◽  
The Cross

This paper develops models for micro-fluid flow in tubular microchannels with uniform or varying cross-sections. The fluid flow is governed by the pressure drop, the capillary force, and the viscous force. The governing equation developed for the flow incorporates two geometry parameters, namely the cross-section perimeter, S, and the cross-section area, A. In a microchannel with a uniform cross-section, the governing equation reduces to a linear initial value problem which can be solved analytically. However, in the case of a varying cross-section, the two geometry parameters vary as a function of the flow front position, L, and the nonlinear initial value problem must be solved numerically. The computational models developed in this study will be able to provide accurate predictions of the micro-fluid flow behavior in microchannels with uniform or varying cross-sections.

Gender determination of caucasoid hair using image analysis

1993 ◽  
Vol 51 ◽  
pp. 216-217
Author(s):  
T.B. Ball ◽  
W.M. Hess
Keyword(s):  
Image Analysis ◽  
Cross Sections ◽  
Scalp Hair ◽  
The Body ◽  
Equivalent Diameter ◽  
Cross Sectional ◽  
Hair Samples ◽  
Length Width ◽  
Morphological Differences

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.

Analysis of variations in and correlations between selected physical parameters of common beech (Fagus silvatica L.) nuts

2017 ◽  
Vol 1 (21) ◽  
pp. 49-63
Author(s):  
Zdzisław Kaliniewicz ◽  
Piotr Markowski ◽  
Andrzej Anders ◽  
Paweł Tylek ◽  
Zbigniew Krzysiak ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Correlation Analysis ◽  
Cross Sections ◽  
Linear Regression Analysis ◽  
Physical Parameters ◽  
Common Beech ◽  
Mesh Screen ◽  
Before And After ◽  
Fagus Silvatica ◽  
Highly Correlated

The basic dimensions and the mass of common beech nuts and seeds from five nut batches, harvested from tree stands in northern Poland, were determined. Environmental conditions had a greater influence on seed plumpness than the age of tree stands. The results of measurements were analyzed statistically by analysis of variance, correlation analysis and linear regression analysis. Despite differences in their plumpness, nuts were characterized by nearly identical cross-sections which resembled an equilateral triangle. The thickness of nuts and seeds was highly correlated with their mass, and this information can facilitate seed husking and separation into mass categories. Before and after husking, seeds should be separated with the use of a mesh screen with longitudinal openings. Medium-sized (most numerous) seeds were separated into the following plumpness categories using a screen separator with ≠6 mm and ≠7 mm openings: 84% of moderately plump seeds, 3% of seeds with reduced plumpness, and 13% of plump seeds.

Automated 3D measurement of fiber cross section morphology in handsheets

2012 ◽  
Vol 27 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Christian Lorbach ◽  
Ulrich Hirn ◽  
Johannes Kritzinger ◽  
Wolfgang Bauer
Keyword(s):  
Image Analysis ◽  
Cross Section ◽  
Cross Sections ◽  
Image Plane ◽  
3D Measurement ◽  
Cross Sectional ◽  
Fiber Cross Section ◽  
Fiber Wall ◽  
Sectional Shape ◽  
Cross Section Geometry

Abstract We present a method for 3D measurement of fiber cross sectional morphology from handsheets. An automated procedure is used to acquire 3D datasets of fiber cross sectional images using an automated microtome and light microscopy. The fiber cross section geometry is extracted using digital image analysis. Simple sample preparation and highly automated image acquisition and image analysis are providing an efficient tool to analyze large samples. It is demonstrated that if fibers are tilted towards the image plane the images of fiber cross sections are always larger than the true fiber cross section geometry. In our analysis the tilting angles of the fibers to the image plane are measured. The resulting fiber cross sectional images are distorted to compensate the error due to fiber tilt, restoring the true fiber cross sectional shape. We use an approximated correction, the paper provides error estimates of the approximation. Measurement results for fiber wall thickness, fiber coarseness and fiber collapse are presented for one hardwood and one softwood pulp.

Study of fluid flow through a channel deformed by piezoelement

2018 ◽  
Vol 13 (3) ◽  
pp. 1-10 ◽  
Author(s):  
I.Sh. Nasibullayev ◽  
E.Sh Nasibullaeva ◽  
O.V. Darintsev
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Boundary Conditions ◽  
Flow Rate ◽  
Contact Surface ◽  
Piezoelectric Element ◽  
Neumann Boundary ◽  
Differential Pressure ◽  
Physical Parameters ◽  
Flow Through

The flow of a liquid through a tube deformed by a piezoelectric cell under a harmonic law is studied in this paper. Linear deformations are compared for the Dirichlet and Neumann boundary conditions on the contact surface of the tube and piezoelectric element. The flow of fluid through a deformed channel for two flow regimes is investigated: in a tube with one closed end due to deformation of the tube; for a tube with two open ends due to deformation of the tube and the differential pressure applied to the channel. The flow rate of the liquid is calculated as a function of the frequency of the deformations, the pressure drop and the physical parameters of the liquid.

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