Laminar Boundary Layer Along Inviscid Surface Streamlines Over Inclined Axisymmetric Bodies in Incompressible Flow

摘要

A computer program has been developed to calculate laminar layers along inviscid surface streamlines over inclined axisymmetric bodies. The inviscid surface streamlines are computed from experimental pressure data using a doubly quadratic spline interpolation technique if an analytical potential solution is not provided. By application of the axisymmetric analog, or small cross flow assumption, the properties of this three-dimensional flow field may be approximated by solving the axisymmetric boundary layer equations over an equivalent axisymmetric body for each inviscid surface streamline. Hall's and Blottner's boundary layer solution methods, both of which utilize a finite difference technique to obtain the local velocity profile, have been incorporated into the computational code. Results are presented for a sphere, an ellipsoid of revolution with thickness ratio of 1/4 at 12 and 30 degrees angle of attack, and a sphere-ogive-cylinder configuration at 45 degrees angle of attack. The latter case utilized experimental pressure data while an analytical potential solution was available for the other configurations. A technique for calculating the streamline metric along an inviscid surface streamline was developed. Boundary layer profiles were calculated along the streamlines from the stagnation point to the separation point.