Lee, Sang-Youp Jang, Jaesung Wereley, Steven T. 2024-01-20T23:03:22Z 2024-01-20T23:03:22Z 2021-08-31 2008-07 1613-4982 https://pubs.kist.re.kr/handle/201004/133375 The effects of planar inlet plenum geometry on the developing flow fields in two rectangular microchannels of reciprocal aspect ratios (H/W similar to 2.75 and similar to 0.40) were investigated for Re(D) = 1-100 using micro particle image velocimetry (mu PIV). These two microchannels were made by a precision sawing and silicon microfabrication techniques. Both the velocity profiles and centerline velocity developments were clearly resolved and extracted along the axial distance from mu PIV results. The entrance lengths were found from the centerline velocities using a decaying exponential fitting function where the centerline velocity reaches 99% of the fully developed centerline velocity. The proposed fitting function showed excellent agreement with the experimental results. The planar plenum was shown to cause an upstream predevelopment resulting in the significant reductions in the entrance lengths. Two entrance length correlations were proposed in the forms of Atkinson et al.'s (AIChE J 15:548-553, 1969) and Chen's (J Fluids Eng 95:153-158, 1973) correlations. The proposed entrance length correlations showed that acquired constant portion and slope of the entrance lengths showed 23-27 and 70-81% reductions for H/W = 2.75 while the entrance length correlation for H/W = 0.40 showed 69-73% increase and 41-63% decrease in the constant portion and slope, respectively. English SPRINGER HEIDELBERG LAMINAR FLOW REYNOLDS-NUMBERS ENTRANCE REGION DUCTS Effects of planar inlet plenums on the hydrodynamically developing flows in rectangular microchannels of complementary aspect ratios Article 10.1007/s10404-007-0179-y 1 MICROFLUIDICS AND NANOFLUIDICS, v.5, no.1, pp.1 - 12 MICROFLUIDICS AND NANOFLUIDICS 5 1 1 12 scie scopus 000256010500001 Nanoscience & Nanotechnology Instruments & Instrumentation Physics, Fluids & Plasmas Science & Technology - Other Topics Instruments & Instrumentation Physics Article LAMINAR FLOW REYNOLDS-NUMBERS ENTRANCE REGION DUCTS entrance length rectangular microchannel hydrodynamically developing flow aspect ratio of rectangular microchannel micro particle image velocimetry