The paper describes a method for viscous flow prediction which includes the prediction
of transition onset location as an integral part of the calculation. The method is similar to
others in that it is based on stability analysis of the boundary layers but acknowledges that
solutions of the Reynolds-averaged Navier-Stokes (RANS) equations yield boundary layers
of inadequate accuracy when conventional mesh sizes are used. The boundary layers are
therefore recomputed to high accuracy by solving the laminar boundary layer equations.
Transition onset locations determined by the stability analysis are passed back to the RANS
solver for further iterations. The method described in this paper differs from others in that
the laminar boundary layer calculation is fully three-dimensional and the stability analysis is
through the fully three-dimensional parabolised stability equations for compressible flow.
Results are presented to illustrate the capability of the laminar boundary layer method and
the effectiveness of the method for solving the parabolised stability equations. In addition,
preliminary validation results are presented from calculations of the viscous flow over the
AFRL 1303 UCAV concept to demonstrate that the fully three-dimensional laminar
boundary layer and stability analysis components can be combined successfully with a
RANS method for calculating flows with natural transition.