AN EXACT SOLUTION OF THE UNSTEADY NAVIER-STOKES EQUATIONS RESULTING FROM A STRETCHING SURFACE

When a stretching surface is moved quickly, for a short period of time , a pulse is transmitted to the surrounding fluid. Here we describe an exact solution in terms of a similarity variable for the Navier-Stoke s equations which represents the effect of this pulse for two-dimensio nal flow. The unusual feature is that this solution is only valid for a limited range of the Reynolds number; outside this domain unbounded velocities result.