Loss characteristics and flow rectification property of diffuser valves for micropump applications

Yi Chun Wang, Jui Cheng Hsu, Ping Chi Kuo, Yung Chun Lee

Research output: Contribution to journalArticlepeer-review

70 Citations (Scopus)


The primary motivation for this work is to provide data on the loss characteristics and flow rectification performance of flat-walled microdiffuser valves for Reynolds numbers between 100 and 2000 which is considered deficient in literature. The diffusers are designed with a fixed slenderness of 15 and an aspect ratio of 0.92 and with diverging angles ranging from 4° to 120°. The total pressure loss coefficient of the diffuser flow is determined experimentally. Components of the loss are studied in detail by numerical simulations. Results from the computations are in satisfactory agreement with the measurements. Simulations are also carried out for nozzle flows. Based on the experimental and the computational results, efficiencies of the diffuser valves are calculated. It is shown that, for laminar flows, global flow separation plays a significant role in reducing the loss of the diffuser. Consequently, the diffuser angle corresponding to the optimum diffuser efficiency varies from 40° at Re = 100 to 20° for Re ≥500.

Original languageEnglish
Pages (from-to)328-336
Number of pages9
JournalInternational Journal of Heat and Mass Transfer
Issue number1-2
Publication statusPublished - 2009 Jan 15

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes


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