Flow separation in constriction microchannels

W. Y. Lee, M. Wong, Y. Zohar

Research output: Contribution to conferencePaperpeer-review

17 Scopus citations


Constriction devices contain an element inserted into the fluid stream, which changes the local streamwise distribution of the flow area. One such element is the orifice-like obstruction with sharp corners, basically a back-to-back abrupt contraction and expansion, which could trigger flow separation. A series of microchannels, 40μm×1μm×4000μm in dimensions, with orifice element at the centers of the channels has been fabricated using standard micromachining techniques. The channel width at the orifice section varied from 10μm to 34μm, and each channel was integrated with a set of pressure sensors. Nitrogen gas was passed through the microdevices under inlet pressure up to 50psi. Mass flow rate was first measured for all the devices as a function of the pressure drop, showing a monotonic decrease of the flow rate with decreasing orifice width. Then, the pressure distributions along the microchannel with the narrowest orifice were recorded, showing a pressure jump across the 10μm-wide orifice. The mass flow rate and pressure measurements indicate the existence of flow separation in the microchannels.

Original languageEnglish (US)
Number of pages4
StatePublished - 2001
Event14th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2001) - Interlaken, Switzerland
Duration: Jan 21 2001Jan 25 2001


Other14th IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2001)

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Mechanical Engineering
  • Electrical and Electronic Engineering


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