Multiple time step approach for numerical simulation of
             non-Newtonian drop coalescence



                     Bazhlekov I.B.

Institute of Mathematics, Bulgarian Academy of Sciences,
   acad. G. Bonchev str., bl. 8, 1113 Sofia, Bulgaria

  Present address: Centre for Polymers and Composites,
Eindhoven University of Technology,
                P.O. Box 513, 5600 MB Eindhoven, The
Netherlands, E-mail - bazhleko@wfw.wtb.tue.nl



                        Abstract

     An approach for numerical simulation of non-Newtonian
coalescence is discussed. The elements of the numerical
scheme are analyzed with respect to their accuracy and
stability as well as the related problems of prohibitively
large CPU time. A multiple time step approach is proposed
both for the time integration of the governing equations in
the film and in the drops. The influence of this approach on
the accuracy of the numerical results is studied and its
efficiency for the numerical simulation of non-Newtonian
drop coalescence demonstrated.