Performance of valveless diffuser micropumps under harmonic piezoelectric actuation

M. T. Ahmadian, M. H. Saidi, Amin Mehrabian, M. Bazargan, S. D. Kenarsari

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations

Abstract

Valveless piezoelectric micropumps are in wide practical use due to their ability to conduct particles with absence of interior moving mechanical parts. The objective of this paper is to obtain the fluid flow response to actuation frequency of a passive diffuser valve under harmonic pressures. In this regards a 2D model of a micropump valves and chambers is analyzed. The analysis is performed for 10Kpa back pressure on micropump chamber and actuation frequencies within the range of 1Hz to 10 KHz. Results show the highest velocity in the direction of diffuser axis occurs at the narrow diffuser neck while flow direction reverses every half period. For low frequencies, a parabolic velocity profile is observed at the valve midway while, instabilities with the tendency of transition to boundary layer dominant profile is observed for high actuation frequencies. Oscillating flow in diffuser indicates existence of high shear stress regions near the wall along with the flow reversal in the center at high frequencies. Both valve and pump net flow rate decrease drastically as the frequency approaches a certain value. From electrical analogy viewpoint, nozzle/diffuser passive valves can be modeled as Low Pass Filters (LPF). The results are in good agreement with the relevant analytical findings. Similar to analytical results, flow rate is approximately in phase with actuation at low frequencies but phase shift ascends as actuation frequency is increased. The main head loss of flow occurs at the diffuser valves while sudden contraction and expansion of streamlines at the diffuser entrance and exit involve only 22% of the total energy. The results are in agreement with the previous experiments of micropump flow at high frequencies.

Original languageEnglish (US)
Title of host publicationProceedings of 8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA 2006
PublisherAmerican Society of Mechanical Engineers
ISBN (Print)0791837793, 9780791837795
DOIs
StatePublished - Jan 1 2006
Event8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006 - Torino, Italy
Duration: Jul 4 2006Jul 7 2006

Publication series

NameProceedings of 8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006
Volume2006

Other

Other8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006
CountryItaly
CityTorino
Period7/4/067/7/06

All Science Journal Classification (ASJC) codes

  • Engineering(all)

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