scholarly journals Electroosmotic flow measurements in a freely suspended liquid film: Experimhents and numerical simulations

2017 ◽  
Vol 38 (20) ◽  
pp. 2554-2560 ◽  
Author(s):  
Abdulkadir Hussein Sheik ◽  
Himiyage Chaminda Hemaka Bandulasena ◽  
Victor Starov ◽  
Anna Trybala
Keyword(s):  
Liquid Film ◽  
Numerical Simulations ◽  
Electroosmotic Flow ◽  
Flow Measurements ◽  
Freely Suspended

scholarly journals Electrokinetic Transport of a Charged Dye in a Freely Suspended Liquid Film: Experiments and Numerical Simulations

Langmuir ◽  
2020 ◽  
Vol 36 (5) ◽  
pp. 1183-1191
Author(s):  
Abdulkadir Hussein Sheik ◽  
Faraz Montazersadgh ◽  
Victor Mikhilovich Starov ◽  
Anna Trybala ◽  
Kahagala Gamage Upul Wijayantha ◽  
...  
Keyword(s):  
Liquid Film ◽  
Numerical Simulations ◽  
Electrokinetic Transport ◽  
Freely Suspended

Light-induced thermoosmosis about conducting ellipsoidal nanoparticles

2019 ◽  
Vol 475 (2223) ◽  
pp. 20180040 ◽  
Author(s):  
Touvia Miloh
Keyword(s):  
Surface Temperature ◽  
Electroosmotic Flow ◽  
Spherical Particles ◽  
Conducting Liquid ◽  
Metallic Nanoparticle ◽  
Continuous Laser ◽  
Surface Slip ◽  
Physical Problems ◽  
Recent Advancement ◽  
Freely Suspended

We consider the central problem of a non-spherical (ellipsoidal) polarizable (metallic) nanoparticle freely suspended in a conducting liquid phase which is irradiated (heated) by a laser under the Rayleigh (electrostatic) approximation. It is shown that, unlike the case of perfectly symmetric (spherical) particles, the surface temperature of general orthotropic particles exposed to continuous laser irradiation is not uniform! Thus, the induced surface slip (Soret type) velocity may lead to a self-induced thermoosmotic flow (sTOF) about the particle, in a similar manner to the electroosmotic flow driven by the Helmholtz—Smoluchowski slippage. Using the recent advancement in the theory of Lamé functions and ellipsoidal harmonics, we analytically present new solutions for two key physical problems. (i) Heat conduction and temperature distribution inside and outside a conducting laser-irradiated homogeneous tri-axial ellipsoid which is subjected to uniform Joule heating. (ii) Creeping (Stokes) sTOF around a fixed impermeable metallic ellipsoidal nanoparticle driven by a Soret-type surface slip velocity (i.e. proportional to the surface-temperature gradient).

Instantaneous Optical Measurement of the Temperature at the Interface Between a Wall and a Thin Liquid Film

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Brian E. Fehring ◽  
Roman W. Morse ◽  
Jason Chan ◽  
Kristofer M. Dressler ◽  
Evan T. Hurlburt ◽  
...  
Keyword(s):  
Laser Beam ◽  
Liquid Film ◽  
Solid Wall ◽  
Incident Angle ◽  
Thin Liquid Film ◽  
Index Of Refraction ◽  
High Temporal Resolution ◽  
Flow Measurements ◽  
Vapor Interface ◽  
Liquid Vapor

Abstract Instantaneous temperature measurements at the interface between a solid wall and a thin, unsteady liquid film are performed using thermoreflectance, a nonintrusive optical technique with high temporal resolution. A laser beam is directed at a wall–liquid interface, and the intensity of the light reflected at that interface is measured by a photodiode. The intensity of the reflected light varies with the index of refraction of the liquid at the wall. The index of refraction is a function of temperature, which enables the instantaneous measurement of the wall temperature. In the presence of thin liquid films, reflections from the liquid–vapor interface at the free surface of the film generate noise in the measurements. We demonstrate that orienting the laser beam at a large incident angle, close to total internal reflection, minimizes noise from the liquid–vapor interface while increasing the sensitivity of the measurement. The thermoreflectance technique is validated in an unsteady two-phase annular flow. Measurements of temperature fluctuations less than 1 K in amplitude are achieved, with an uncertainty of 0.1 K.

Experimental Investigation of Falling Liquid Film in Vertical Downward Two-Phase Pipe Flow

2012 ◽  
Author(s):  
Jose M. Lopez ◽  
Ram Mohan ◽  
Ovadia Shoham ◽  
Shoubo Wang ◽  
Gene Kouba
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Two Phase Flow ◽  
Liquid Velocity ◽  
Liquid Droplet ◽  
Mineral Oil ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Measurements ◽  
Falling Liquid Film

In this research the hydrodynamics of falling liquid film in a vertical downward two-phase flow (liquid-gas) is experimentally studied. The 4 inch clear PVC test section is 6.1 meters long, with a length to diameter ratio (L/D) of 64. The fluids utilized are compressed air, water, Conosol mineral oil (light oil) and Drake mineral oil (heavy oil). The superficial liquid velocities tested range from 12 to 72 cm/s while the superficial gas velocities range from 0.2 to 29 cm/s. The vertical facility is equipped with the state-of-the-art instrumentation for two-phase flow measurements, the capacitance Wire-Mesh Sensor (WMS), allowing two-phase flow measurements with conducting and non conducting fluids. Experimental results show that the liquid film thickness has a quasi-linear relationship with the superficial liquid velocity for the air-water case. For the air-oil cases, at superficial liquid velocities higher than 50 cm/s, the liquid film thickness trend is affected by the liquid droplet entrainment. Furthermore, it was found that the liquid droplet entrainment increases as the superficial liquid velocity increases or the surface tension decreases. Details of the liquid droplets traveling in the gas core, wave formation, wave breakup and film thickness evolution are observed in the WMS phase reconstruction.

scholarly journals Fabrication and electroosmotic flow measurements in micro- and nanofluidic channels

2005 ◽  
Vol 2 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Thomas S. Hug ◽  
Nicolas F. de. Rooij ◽  
U. Staufer
Keyword(s):  
Electroosmotic Flow ◽  
Flow Measurements ◽  
Nanofluidic Channels

scholarly journals Performances and Flow Analysis in the Centrifugal Vortex Pump

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
Tihomir Mihalić ◽  
Zvonimir Guzović ◽  
Andrej Predin
Keyword(s):  
Numerical Simulations ◽  
Centrifugal Pump ◽  
Fluid Dynamic ◽  
Flow Analysis ◽  
Physical Models ◽  
Back Side ◽  
Additional Energy ◽  
Flow Measurements ◽  
Vortex Pump ◽  
Fluid Particles

Improvements to the characteristics of a centrifugal pump through the addition of a vortex rotor were investigated both experimentally and with computational fluid dynamic (CFD) analysis. The idea behind that improvement is in creating so-called coherent structures of eddies and turbulence in the peripheral area of the vortex rotor mounted at the back side of centrifugal rotor. Research on the energy transformations in the centrifugal vortex pump in this work was carried out using numerical simulations of the flow in the centrifugal and the centrifugal vortex pump. Measurements of relevant parameters that describe the performance of pumps, at their physical models, were gained from experiments. The measurement results were used as experimental validation of numerical simulations. In contrast, flow visualization derived from the numerical simulation was used to interpret measurements. In deriving the experimental procedure, special care was taken with the flow measurements. The reason for this is in the fact that the flow measurements had the biggest influence on the overall measurement uncertainty. However, flow measurements were the most demanding with regards to the experiment design and in taking the measurement readings. This experimental-CFD research made it possible to undertake an assessment of vortex rotor contribution on the head of the centrifugal vortex pump. The influence of the vortex rotor on the efficiency of the centrifugal vortex pump was investigated by comparing it with the efficiency of the centrifugal pump with the same geometry. An analysis of the flow structure was conducted in order to better understand the energy transformations that are the result of the interaction between the flow from the channels of the centrifugal part of the centrifugal vortex rotor and vortices formed at the vortex part of the centrifugal vortex rotor as well as their interactions with the stator. It was shown that this additional energy significantly increases pump head while increasing pump stability. This synergetic work has demonstrated that while vortex rotor gives additional energy to the fluid particles, that did not enter stator due to the energy lack by changing their momentum; at the same time, some of the kinetic energy contained in the vortex rotor induced vortices is also added to those fluid particles.

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