{"title":"Electroviscous Effects in Low Reynolds Number Flow through a Microfluidic Contraction with Rectangular Cross-Section","authors":"Malcolm R Davidson, Ram P. Bharti, Petar Liovic, Dalton J.E. Harvie","country":null,"institution":"","volume":16,"journal":"International Journal of Chemical and Molecular Engineering","pagesStart":40,"pagesEnd":45,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/8940","abstract":"The electrokinetic flow resistance (electroviscous\r\neffect) is predicted for steady state, pressure-driven liquid flow at\r\nlow Reynolds number in a microfluidic contraction of rectangular\r\ncross-section. Calculations of the three dimensional flow are\r\nperformed in parallel using a finite volume numerical method. The\r\nchannel walls are assumed to carry a uniform charge density and the\r\nliquid is taken to be a symmetric 1:1 electrolyte. Predictions are\r\npresented for a single set of flow and electrokinetic parameters. It is\r\nshown that the magnitude of the streaming potential gradient and the\r\ncharge density of counter-ions in the liquid is greater than that in\r\ncorresponding two-dimensional slit-like contraction geometry. The\r\napparent viscosity is found to be very close to the value for a\r\nrectangular channel of uniform cross-section at the chosen Reynolds\r\nnumber (Re = 0.1). It is speculated that the apparent viscosity for the\r\ncontraction geometry will increase as the Reynolds number is\r\nreduced.","references":null,"publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 16, 2008"}