LONGITUDINAL AND TORSIONAL OSCILLATIONS OF A ROD IN AN OLDROYD-B FLUID WITH SUCTION OR INJECTION

The axisymmetric flow of a homogeneous Oldroyd-B fluid due to the long itudinal and torsional oscillations of an infinite circular rod is stu died. At the surface of the rod, suction or injection velocity is appl ied. The motion and the constitutive equations from a system of P.D.E. s solved numerically. Only in few cases can the numerical results be c ompared with some known analytical solutions. Numerical experiments sh ow the effect of the non-Newtonian dimensionless parameters on the vel ocity and on the shear stresses.