Pseudoplastic entry flow in straight and convergent channels

Abstract

<p> Power law fluids are analysed for entry flow in straight and converging channels in their pseudoplastic region (0.0≤n≤1.0). The motion and energy equations simplified by the boundary layer assumptions were solved by an implicit finite difference scheme with a marching procedure. To circumvent the difficulties arising from an infinite viscosity at zero shear rate, a minimum value of shear rate was used making the fluid newtonian at low shear rates. </p> <p> Entrance flows between parallel plates of infinite width (Slit) for uniform entry profile are discussed in Part I and converging flows for non-parallel flat plates is the subject of Part II of this work. Results are compared with their equivalent in the current literature for the newtonian case; new results are presented for non-newtonian fluids. These results include velocity and temperature profiles, pressure drops, Nusselt number, and entry lengths as a function of the flow behavior index (n) and the taper angle. </p>