VISCOUS FINGERING WITH ADVERSE ANISOTROPY - A NEW SAFFMAN-TAYLOR FINGER

Viscous fingering in a linear channel is investigated in the presence of anisotropy, when the directions of easy growth are at 45-degrees to the direction of the cell axis. Experimentally, when the velocity is increased, the stable fingers and the averaged unstable ones tend to o ccupy an increasing fraction of the cell width, in contrast with the s tandard situation. The numerical simulation and the analytical investi gation reveal the existence of a new solution for the Saffman-Taylor f inger which does not belong to the standard manifold.