University of Hertfordshire

Optimization of diffuser/nozzle elements for rectification valveless micropumps

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

  • A. Azarbadegan
  • Cesar Cortes Quiroz
  • E. Moeendarbary
  • Ian Eames
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Original languageEnglish
Title of host publicationProcs of the 8th Int Conf on Nanochannels, Microchannels and Minichannels 2010
Subtitle of host publicationPTS A AND B
PublisherThe American Society of Mechanical Engineers
Pages1155-1161
Number of pages7
ISBN (Print)978-0-7918-5450-1
DOIs
Publication statusPublished - 2011
Event8th International Conference on Nanochannels, Microchannels and Minichannels - Montreal
Duration: 1 Aug 20105 Aug 2010

Conference

Conference8th International Conference on Nanochannels, Microchannels and Minichannels
CityMontreal
Period1/08/105/08/10

Abstract

There has been a growing interest in understanding the flow behaviour inside diffuser/nozzle elements in order to identify performance characteristics of these elements for micropump applications. Flat-walled diffuser/nozzle element is the most commonly used type for valveless micropump applications due to its ease of fabrication and compact design. In this paper, we study generic flat-walled diffuser/nozzle elements and apply optimization techniques to explore how the pumping efficiency can be improved by changing geometry to provide higher rectification efficiency and lower pressure drop in rectification valveless micropumps. The primary motivation for this study is to evaluate the performance of flat-walled diffuser/nozzle elements based on geometry variations under several Reynolds numbers (Re). In this study we employ a design methodology for diffuser/nozzle elements that incorporates computational fluid dynamics (CFD) within an optimization methodology. To start the process a series of geometric parameters are selected including element neck width, depth, divergence angle, and entrance fillet radius. Then, the pressure drop and rectification property of an element are calculated as performance parameters, i.e., by varying the geometry it is desirable to maximise pressure rise and the rectification property of the element. Design of experiments (DOE) is employed to generate the experimental table which corresponds to different geometries representing the design space. These limited numbers of geometries generated by DOE are evaluated by using CFD to obtain corresponding performance parameters. By preparing all the design and performance parameters, Surrogate model (SM) technique is applied to obtain the relationship (approximation function) between design and performance parameters. Eventually, based on the developed approximation functions or response surfaces, a multi-objective genetic algorithm (MOGA) is employed to maximise pressure rise and rectification property of diffuser/nozzle element. This design methodology is a very powerful tool to design and optimise flat-walled diffuser/nozzle elements for micropump applications and can speed up the micropump design process significantly.

Notes

Paper no. FEDSM-ICNMM2010-30856

ID: 679685