Group Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Title: 2.2.3 - Sensing bubble impacts with active and passive microcantilevers
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 Material Information
Title: 2.2.3 - Sensing bubble impacts with active and passive microcantilevers Particle Bubble and Drop Dynamics
Series Title: 7th International Conference on Multiphase Flow - ICMF 2010 Proceedings
Physical Description: Conference Papers
Creator: Stegmeir, M.
Longmire, E.
Mantell, S.
Publisher: International Conference on Multiphase Flow (ICMF)
Publication Date: June 4, 2010
Subject: bubbles
bubble impact
cantilever sensors
Abstract: The sensitivity of microfabricated cantilevers with integrated strain gauge sensing to collisions of air bubbles in confined water channel flow was investigated. Flow was upward through the vertical channel of 585mm length and 10mmx2mm cross-section. Bubbles of diameter 400-2000 m were examined, and channel Reynolds number based on mean fluid velocity and hydraulic diameter was varied between 1000 and 2500. Bubble Weber numbers (WeB = U2 BubbleD ) and impact offsets (B = 2d D where d is the impact offset distance) were varied (2<WeB<8, 0<B<1). Magnetic-tipped cantilevers extended from the 2mm wall near the channel midplane. The cantilevers measured 6mmx2mmx125 m and 3mmx0.5mmx125 m with resonance frequencies of 340Hz and 2670Hz in water. Bubbles were introduced far upstream of the cantilever mounting location and traveled in the flow direction. Active and passive sensing were investigated. For active sensing cases, cantilevers were oscillated perpendicular to the flow direction by applying a sinusoidally varying magnetic field at their resonance frequency. Recorded strain gauge data were correlated with bubble image sequences and processed to extract sinusoidal amplitude time series for each impact recorded. Two types of change in instantaneous sinusoidal amplitude were observed to be associated with bubble impacts. The first was associated only with active cantilevers. Bubbles impacting active cantilevers caused a drop in sinusoidal amplitude while in contact with the cantilever. This effect was observed consistently across the range of parameters considered. The second change was observed for both active and passive cantilevers. Bubbles impacting active or passive cantilevers at sufficiently high WeB and moderate B produced an amplitude spike immediately following detachment. The presence and magnitude of this effect varied significantly with impact parameters.
General Note: The International Conference on Multiphase Flow (ICMF) first was held in Tsukuba, Japan in 1991 and the second ICMF took place in Kyoto, Japan in 1995. During this conference, it was decided to establish an International Governing Board which oversees the major aspects of the conference and makes decisions about future conference locations. Due to the great importance of the field, it was furthermore decided to hold the conference every three years successively in Asia including Australia, Europe including Africa, Russia and the Near East and America. Hence, ICMF 1998 was held in Lyon, France, ICMF 2001 in New Orleans, USA, ICMF 2004 in Yokohama, Japan, and ICMF 2007 in Leipzig, Germany. ICMF-2010 is devoted to all aspects of Multiphase Flow. Researchers from all over the world gathered in order to introduce their recent advances in the field and thereby promote the exchange of new ideas, results and techniques. The conference is a key event in Multiphase Flow and supports the advancement of science in this very important field. The major research topics relevant for the conference are as follows: Bio-Fluid Dynamics; Boiling; Bubbly Flows; Cavitation; Colloidal and Suspension Dynamics; Collision, Agglomeration and Breakup; Computational Techniques for Multiphase Flows; Droplet Flows; Environmental and Geophysical Flows; Experimental Methods for Multiphase Flows; Fluidized and Circulating Fluidized Beds; Fluid Structure Interactions; Granular Media; Industrial Applications; Instabilities; Interfacial Flows; Micro and Nano-Scale Multiphase Flows; Microgravity in Two-Phase Flow; Multiphase Flows with Heat and Mass Transfer; Non-Newtonian Multiphase Flows; Particle-Laden Flows; Particle, Bubble and Drop Dynamics; Reactive Multiphase Flows
 Record Information
Bibliographic ID: UF00102023
Volume ID: VID00045
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: 223-Stegmeir-ICMF2010.pdf

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