Measuring Particle Positions in Micro Channel with Multifiber Array

2013 ◽  
Vol 25 (6) ◽  
pp. 1105-1113
Author(s):  
Ichiro Okuda ◽  
◽  
Yasushi Mae ◽  
Kenichi Ohara ◽  
Tomohito Takubo ◽  
...  
Keyword(s):  
Laser Light ◽  
Flow Direction ◽  
Three Dimensional ◽  
Micro Channel ◽  
Position Measurement ◽  
Micro Channels ◽  
Dimensional Measurements ◽  
Vertically Aligned ◽  
Pdms Chip ◽  
Different Diameters

This paper proposes position measurement of particles in micro channels fabricated on a polydimethylsiloxane (PDMS) chip using a two-layer plastic optical fiber (POF) array. Particle positions are measured by irradiating the POF array with laser light and measuring the decrease in POF output power posed by the presence of the particle. Our proposed sensor provides three dimensional measurements in the micro channel along the directions of the length, depth and the width. We demonstrate that plural particles of different diameters can be measured with our proposed sensor in which two layers of POF are vertically aligned or shifted along the flow direction. The effects of optical misalignment of POF array with respect to the measurement are theoretically and experimentally evaluated.

Three-Dimensional Numerical Simulation of the Flow around Two Side-by-Side Cylinders of Different Diameters

2014 ◽  
Vol 721 ◽  
pp. 199-202
Author(s):  
Zhen Xiao Bi ◽  
Zhi Han Zhu
Keyword(s):  
Numerical Simulation ◽  
Flow Direction ◽  
Three Dimensional ◽  
Cross Flow ◽  
Simulation Method ◽  
Scale Model ◽  
Hydrodynamic Characteristics ◽  
Eddy Simulation ◽  
Drag And Lift ◽  
Different Diameters

This paper presents the calculation of hydrodynamic characteristics of two side-by-side cylinders of different diameters in three dimensional incompressible uniform cross flow by using Large-eddy simulation method based on dynamical Smagorinsky-Lilly sub-grid scale model. Solution of the three dimensional N-S equations were obtained by the finite volume method. The numerical simulation focused on investigating the characteristic of the pressure distribution (drag and lift force), vorticity field and turbulence Re=. Results shows that, the asymmetry of the time –averaged velocity distribution in the flow direction behind the two cylinders is very obvious; the frequency of eddy shedding of the small cylinder is about twice of the large one. The turbulence of cylinders is more obvious.

scholarly journals Secondary Flow Effects and Mixing of the Wake Behind a Turbine Stator

1982 ◽  
Author(s):  
A. Binder ◽  
R. Romey
Keyword(s):  
Secondary Flow ◽  
Flow Direction ◽  
Three Dimensional ◽  
Detailed Knowledge ◽  
Pressure Loss Coefficient ◽  
Turbine Stator ◽  
Dimensional Measurements ◽  
Order Of Magnitude ◽  
Flow Effects ◽  
Secondary Vortices

In highly loaded turbines with large hub/tip ratios there is a marked increase in secondary flow effects. The optimization of the turbine flow requires detailed knowledge both of three-dimensional cascade flow and of the wake impinging on the downstream rows of airfoils. Therefore, in the DFVLR, thorough investigations of a single-stage turbine with cold air flow were performed. The stator of this turbine was designed for transonic flow and has a hub/tip ratio of 0.756 and an aspect ratio of 0.56. First, measurements were taken without the rotor in several sections behind the turbine stator with special regard to the mixing of the wakes and secondary vortices. Distributions of total pressure loss coefficient and flow direction give the order of magnitude of the mixing losses. Also, position, intensity, structure, and development of secondary vortices are shown. Some complementary measurements were carried out using five-hole probes. They confirm the above described results from two-dimensional measurements.

Position and Posture Measurement Method of the Omnidirectional Camera Using Identification Markers

2018 ◽  
Vol 30 (3) ◽  
pp. 354-362 ◽  
Author(s):  
Naoya Hatakeyama ◽  
◽  
Tohru Sasaki ◽  
Kenji Terabayashi ◽  
Masahiro Funato ◽  
...  
Keyword(s):  
Measurement Method ◽  
Position Control ◽  
Three Dimensional ◽  
Position Estimation ◽  
Position Measurement ◽  
Omnidirectional Camera ◽  
Camera Systems ◽  
Dimensional Measurements ◽  
Aerial Vehicle ◽  
Image Position

Recently, many studies on unmanned aerial vehicle (UAVs) that perform position control using camera images have been conducted. The measurements of the surrounding environment and position of the mobile robot are important in controlling the UAV. The distance and direction of the optical ray to the object can be obtained from the diameter and coordinates in the image. In these studies, various camera systems using plane cameras, fisheye cameras, or omnidirectional cameras are used. Because these camera systems have different geometrical optics, one simple image position measurement method cannot yield the position and posture. Therefore, we propose a new method that measures the position from the size of three-dimensional landmarks using omnidirectional cameras. Three-dimensional measurements are performed by these omnidirectional cameras using the distance and direction to the object. This method can measure three-dimensional positions from the direction and distance of the ray; therefore, if the optical path such as the reflection or refraction is known, it can perform measurements using a different optical system’s camera. In this study, we construct a method to obtain the relative position and relative posture necessary for the self-position estimation based on an object with an omnidirectional camera; further, we verify this method by experiment.

Effect of Inlet Plenum on Pressure Drop and Velocity in Fractal Micro Channels

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Gurjit Singh ◽  
S.S. Sehagal
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Aspect Ratio ◽  
Constant Velocity ◽  
Computational Analysis ◽  
Three Dimensional ◽  
Micro Channel ◽  
Ratio Model ◽  
Micro Channels ◽  
Inner Channel

The computational analysis for micro channel flow in a branched network was investigated by three dimensional CFD approach. The effect of the change of Inlet Plenum (IP) size at a constant Aspect Ratio (AR) of the outermost channel on pressure drop in a fractal branched micro channel was performed. The properties are compared along a particular path and it was observed that the pressure drop along a bifurcated path has considerably less effect when compared to that of the outer most straight branched channel for a constant aspect ratio model. Pressure does not change significantly if we change the IP radius even when all other parameters are constant. Velocity in the inner channel after a straight run has reduced significantly even for same AR and Reynolds Number (Re). This leads to the conclusion that the IP size affects the velocity after the bifurcation.

Secondary Flow Effects and Mixing of the Wake Behind a Turbine Stator

1983 ◽  
Vol 105 (1) ◽  
pp. 40-46 ◽  
Author(s):  
A. Binder ◽  
R. Romey
Keyword(s):  
Secondary Flow ◽  
Flow Direction ◽  
Three Dimensional ◽  
Detailed Knowledge ◽  
Pressure Loss Coefficient ◽  
Turbine Stator ◽  
Dimensional Measurements ◽  
Order Of Magnitude ◽  
Flow Effects ◽  
Secondary Vortices

In highly loaded turbines with large hub/tip ratios there is a marked increase in secondary flow effects. The optimization of the turbine flow requires detailed knowledge both of three-dimensional cascade flow and of the wake impinging on the downstream rows of airfoils. Therefore, in the DFVLR, thorough investigations of a single-stage turbine with cold air flow were performed. The stator of this turbine was designed for transonic flow and has a hub/tip ratio of 0.756 and an aspect ratio of 0.56. First, measurements were taken without the rotor in several sections behind the turbine stator with special regard to the mixing of the wakes and secondary vortices. Distributions of total pressure loss coefficient and flow direction give the order of magnitude of the mixing losses. Also, position, intensity, structure, and development of secondary vortices are shown. Some complementary measurements were carried out using five-hole probes. They confirm the above described results from two-dimensional measurements.

3D Numerical Analysis of Velocity Profiles of PD, EO and Combined PD-EO Flows Through Microchannels

2006 ◽  
Author(s):  
Shahrzad Yazdi ◽  
Reza Monazami ◽  
Mahmoud A. Salehi
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Charge Distribution ◽  
Three Dimensional ◽  
Flow Patterns ◽  
Ionic Concentration ◽  
Micro Channel ◽  
Micro Channels ◽  
Wide Range ◽  
Pressure Driven

In this paper, a three-dimensional numerical model is developed to analyze flow characteristics of pressure driven, electroosmotic and combined pressure driven-electroosmotic flows through micro-channels. The governing system of equations consists of the electric-field and flow-field equations. The solution procedure involves three steps. The net charge distribution on the cross section of the micro-channel is computed by solving two-dimensional Poisson-Boltzmann equation using the finite element method. Then, using the computed fluid’s charge distribution, the magnitude of the resulting body force due to interaction of an external electric field with the charged fluid is calculated along the micro-channel. Finally, three dimensional Navier-Stokes equations are solved by considering the presence of the electro-kinetic body forces in the flow system for electroosmotic and combined pressure driven electroosmotic flow cases. The results reveal that the flow patterns for combined PD-EO cases are significantly different from the parabolic velocity profile of the laminar pressure-driven flow. The effect of the liquid bulk ionic concentration and the external electric field strength on flow patterns through the square-shaped micro-channels is also investigated over a wide range of external electric field strengths and bulk ionic concentration.

Experimental Study of Micro-Flowing Characteristics of Liquid Transport in Round Micro-Channels

2006 ◽  
Vol 532-533 ◽  
pp. 29-32
Author(s):  
Zhi Yong Ling ◽  
Ji Chang Yang ◽  
Jian Ning Ding ◽  
Yong Liu ◽  
Zhi Wen Zhuang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Microelectromechanical Systems ◽  
Scale Effects ◽  
Flow Theory ◽  
Distilled Water ◽  
Micro Channel ◽  
Silicon Oil ◽  
Low Viscosity ◽  
Micro Channels ◽  
Different Diameters

Micro-flowing technique gained popular applications in microdevices of microelectromechanical systems (MEMS), and the performance of micro-devices is greatly determined by the properties of micro-flow. This paper studied the characteristics of different viscosity fluid flowing over microchannels with different diameters and lengths under low pressure driving, and the influence of scale effects on the flowing characteristics of low viscosity fluids was also examined. The experiments studied the flow rate–pressure characteristics of distilled water flowing over microchannels with diameter of 13 μm, 20 μm, and silicon oil flowing over microchannels with diameters of 50 μm, 100 μm. The results indicate that, when the diameter of micro-channel is more than 20 μm, the flowing characteristics of distilled water and silicon oil agrees well with conventional flow theory, and when the diameter of microchannels is 13μm, the flowing characteristics are related to the length of micro-channel. When the length is relatively shorter, the flowing characteristics are almost in agreement with the conventional flow theory. When the length reaches 100 mm, the flow rate is much higher than the values predicted by theoretical calculation when the length reaches 100 mm. It is obvious that scale effect arises when the length arrives to 100 mm and the velocity slippage results in the great increase of flow rate.

Influence of Thermo-Physical Properties on the Flow and Heat Transfer in Rectangular Micro-Channels

2011 ◽  
Vol 347-353 ◽  
pp. 2640-2644 ◽  
Author(s):  
Xue Tao Duan ◽  
Bin Xu ◽  
Hao Luo
Keyword(s):  
Heat Transfer ◽  
Physical Properties ◽  
Flow Direction ◽  
Three Dimensional ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Flux Boundary Condition ◽  
Flow And Heat Transfer ◽  
Friction Factors ◽  
Micro Channels

This paper investigated the behaviors of flow and heat transfer of single-phase in rectangular micro-channels with three-dimensional numerical analysis. The single micro-channel is 200μm deep, 50μm wide. Deionized water was used as the working fluid. The fluid physical properties varying with temperature and Re number were studied. Comparisons were made among the results obtained from experiments, numerical simulations, and from those in the literature. The results indicated that the friction factors decreasing along the flow direction were ascribed to the fluid temperature rising under the unified heat flux boundary condition. It was found that influence of viscosity variation with temperature and viscous dissipation effect could be too significant to be neglected.

scholarly journals Three dimensional measurements of asphaltene deposition in a transparent micro-channel

2016 ◽  
Vol 145 ◽  
pp. 77-82 ◽  
Author(s):  
Y. Zhuang ◽  
A. Goharzadeh ◽  
Y.J. Lin ◽  
Yit F. Yap ◽  
J.C. Chai ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Micro Channel ◽  
Asphaltene Deposition ◽  
Dimensional Measurements

scholarly journals COMPARISON OF HEAT TRANSFER & FLUID FLOW IN THE MICRO-CHANNEL WITH RECTANGULAR AND HEXAGONAL CROSS SECTION

2020 ◽  
Vol 1 (21) ◽  
Author(s):  
Emami Sajjad ◽  
Hosein Dibaei Bonab Mohammad ◽  
Mohammadiun Mohammad ◽  
Mohammadiun Hamid ◽  
Sadi Maisam
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Heat Transfer Fluid ◽  
Navier Stokes ◽  
Micro Channel ◽  
Rectangular Microchannel ◽  
Micro Channels

Due to the shrinking of the industrial equipment, the heat transfer and cooling of these devices are ofparticular importance. Therefore, this paper studies fluid flow and heat transfer in a micro-channel. Inthis study three-dimensional laminar numerical simulations, based on the Navier–Stokes equations andenergy equation, are obtained for pressure drop and heat transfer in these micro-channel heat sinksunder the same conditions. In this article, the first step is to investigate the effect of channel shape andgeometry on the heat transfer and pressure drop in micro-channels. In, the second step, the effect ofundefined heat flux and distinct input condition is investigated, and third step, the effect of increasingthe number of channels is checked to do an ideal form of heat transfer in a micro-channel. According tothe results, heat transfer using a hexagonal micro-channel is improved 20% on the rectangular microchannel(with equal hydraulic diameter).

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