Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 09, 2022
The flow characteristics of the single-phase flow including the Newtonian and Non-Newtonian liquids were experimentally investigated in a horizontal rectangular micro-channel with a sudden expansion specifically the pressure changes across the expansion. The rectangular cross-sectional dimension has Wu × Hu (width × height) =0.50×0.50mm2 on the upstream side and Wd × Hd(width × height) = 1.0 × 0.50mm2 on the downstream side. Distilled water and three series of non-Newtonian shear-thinning liquid were used as the test liquid. The two different methods were used to determine the pressure change across the expansion. The expansion loss coefficient, Ke, was obtained from the pressure change data. The Ke for Newtonian liquid (water) is almost constant over a generalized Reynolds number tested. On the other side, the Ke for viscoelastic non-Newtonian liquids show unusual characteristics that are different from Newtonian fluids specially under low Reynolds number.