Abstract:
The laminar flow of Newtonian and non-Newtonian fluids through concentric annuli with
center body rotation has been studied numerically. The scope of this study is limited to
numerical prediction of axial velocity profiles and tangential velocity profiles at steady state
condition. A general computer program "TEACH-T' has been modified for this purpose. The
program was used after sufficient justification. The computer program is used for the
prediction of the axial and tangential velocities. In the present study, confined flow through a
concentric annuli with center body rotation is examined numerically by solving the modified
Navier-Stokes Equations. Measurement of the axial and tangential components of velocity is
presented in non-dimensional form for two liquids, one Newtonian and the other a shear
thinning non-Newtonian fluid. The annular geometry consists of a rotating center body with
angular speed of 126 rpm and a radius ratio of 0.506.
The solution of governing set of partial differential Equations is done by finite difference
computation. A non-uniform grid arrangement of 52x32 with multiple repetition is used. The
governing equations have been integrated numerically with the aid of a finite-volume method.
The Hybrid scheme and the central differencing scheme was adopted to properly account for
convection-diffusion effects, and the coupling of continuity with the momentum Equations was
treated with the SIMPLE algorithm. The numerical predictions have been confirmed by
comparing them with the experimentally derived axial and tangential velocity profiles obtained
for a Newtonian fluid and a non-Newtonian shear thinning polymer. For the non-Newtonian
(CMC) fluid, the study was carried out for Reynold's number of 110, 350 and 4400. For the
Newtonian (Glucose) fluid, the study was carried out at Reynold's number of 800 and 1200.
