Magnetic effect on direct numerical simulations of fluid flow through a rotating rectangular straight duct

2011 ◽  
Vol 42 (3) ◽  
pp. 327-342
Author(s):  
Mohammad Wahiduzzaman ◽  
Md. Kamruzzaman ◽  
Md. Mahmud Alam ◽  
M. Ferdows
Keyword(s):  
Fluid Flow ◽  
Numerical Simulations ◽  
Magnetic Effect ◽  
Direct Numerical Simulations ◽  
Flow Through ◽  
Straight Duct

scholarly journals Combined numerical and experimental study of microstructure and permeability in porous granular media

2020 ◽  
Author(s):  
Philipp Eichheimer ◽  
Marcel Thielmann ◽  
Wakana Fujita ◽  
Gregor J. Golabek ◽  
Michihiko Nakamura ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Numerical Simulations ◽  
Granular Media ◽  
Large Scale ◽  
Earth Science ◽  
Numerical Models ◽  
Effective Porosity ◽  
Flow Properties ◽  
Wide Range ◽  
Flow Through

Abstract. Fluid flow on different scales is of interest for several Earth science disciplines like petrophysics, hydrogeology and volcanology. To parameterize fluid flow in large-scale numerical simulations (e.g. groundwater and volcanic systems), flow properties on the microscale need to be considered. For this purpose experimental and numerical investigations of flow through porous media over a wide range of porosities are necessary. In the present study we sinter glass bead media with various porosities. The microstructure, namely effective porosity and effective specific surface, is investigated using image processing. We determine flow properties like hydraulic tortuosity and permeability using both experimental measurements and numerical simulations. By fitting microstructural and flow properties to porosity, we obtain a modified Kozeny-Carman equation for isotropic low-porosity media, that can be used to simulate permeability in large-scale numerical models. To verify the modified Kozeny-Carman equation we compare it to the computed and measured permeability values.

scholarly journals Microtomography-based numerical simulations of heat transfer and fluid flow through β -SiC open-cell foams for catalysis

2016 ◽  
Vol 278 ◽  
pp. 350-360 ◽  
Author(s):  
Xiaolei Fan ◽  
Xiaoxia Ou ◽  
Fei Xing ◽  
Glen A. Turley ◽  
Petr Denissenko ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Simulations ◽  
Open Cell ◽  
Flow Through ◽  
Open Cell Foams

Direct Simulation Based Model-Predictive Control of Flow Maldistribution in Parallel Microchannels

2009 ◽  
Vol 131 (11) ◽  
Author(s):  
Mathieu Martin ◽  
Chris Patton ◽  
John Schmitt ◽  
Sourabh V. Apte
Keyword(s):  
Fluid Flow ◽  
Model Predictive Control ◽  
Numerical Simulations ◽  
Active Control ◽  
Predictive Control ◽  
Nonlinear Flow ◽  
Flow Simulations ◽  
Flow Through ◽  
Parallel Microchannels ◽  
Flow Maldistribution

Flow maldistribution, resulting from bubbles or other particulate matter, can lead to drastic performance degradation in devices that employ parallel microchannels for heat transfer. In this work, direct numerical simulations of fluid flow through a prescribed parallel microchannel geometry are performed and coupled with active control of actuated microvalves to effectively identify and reduce flow maldistribution. Accurate simulation of fluid flow through a set of three parallel microchannels is achieved utilizing a fictitious-domain representation of immersed objects such as microvalves and artificially introduced bubbles. Flow simulations are validated against experimental results obtained for flow through a single high-aspect ratio microchannel, flow around an oscillating cylinder, and flow with a bubble rising in an inclined channel. Results of these simulations compare very well to those obtained experimentally, and validate the use of the solver for the parallel microchannel configuration of this study. System identification techniques are employed on numerical simulations of fluid flow through the geometry to produce a lower dimensional model that captures the essential dynamics of the full nonlinear flow, in terms of a relationship between valve angles and the exit flow rate for each channel. A model-predictive controller is developed, which employs this reduced order model to identify flow maldistribution from exit flow velocities and to prescribe actuation of channel valves to effectively redistribute the flow. Flow simulations with active control are subsequently conducted with artificially introduced bubbles. The model-predictive control methodology is shown to adequately reduce flow maldistribution by quickly varying channel valves to remove bubbles and to equalize flow rates in each channel.

A Novel AFM Chip for Fountain Pen Nanolithography - Design and Microfabrication

2003 ◽  
Vol 782 ◽  
Author(s):  
Keun-Ho Kim ◽  
Nicolaie Moldovan ◽  
Changhong Ke ◽  
Horacio D. Espinosa
Keyword(s):  
Thin Films ◽  
Atomic Force Microscopy ◽  
Fluid Flow ◽  
Numerical Simulations ◽  
Gold Substrate ◽  
Force Microscopy ◽  
Atomic Force ◽  
Air Interface ◽  
Flow Through ◽  
Afm Probe

ABSTRACTA novel atomic force microscopy (AFM) probe has been developed to expand the capability and applications of dip-pen nanolithography (DPN) technology. This new probe has integrated microchannels and reservoirs for continuous ink feed, which allow “fountain-pen” writing called “Fountain Pen Nanolithography” (FPN). Ink is transported from the reservoirs through the microchannels and eventually dispensed onto substrates via a volcano-like dispensing tip. Numerical simulations have been performed to select optimal materials and suitable tip shapes providing a stable fluid-air interface in the tip. Microchannel and dispensing tip have been fabricated by surface micromachining, in particular employing 3 layers of thin films. Fluid flow through the microchannels has been experimentally examined. The probe was used to write on a gold substrate.

scholarly journals Validation Strategy of Reduced-Order Two-Fluid Flow Models Based on a Hierarchy of Direct Numerical Simulations

2020 ◽  
Vol 105 (4) ◽  
pp. 1381-1411
Author(s):  
Pierre Cordesse ◽  
Alberto Remigi ◽  
Benjamin Duret ◽  
Angelo Murrone ◽  
Thibaut Ménard ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Numerical Simulations ◽  
Direct Numerical Simulations ◽  
Reduced Order ◽  
Flow Models ◽  
Two Fluid ◽  
Validation Strategy
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