Numerical Modeling of Rotating Band Flow Field and Comparison with Experiment.

摘要

A numerical model for supersonic, turbulent flow over a projectile rotating band is described. An approximate geometric representation for the separation regions ahead of and behind the band is used to create realistic compression and expansion regions in the projectile boundary layer. The upstream and downstream ramp are found roughly consistant with the expected interaction regions as observed on forward and backward facing steps. The calculated maximum and minimum pressures agree well with data obtained on a 6 caliber Secant-Ogive-Cylinder model tested in the Naval Surface Weapons Center supersonic wind tunnel at Mach number of 3. Boundary layer profiles were measured on, and downstream of the rotating band using a Laser Doppler Velocimeter. These profiles were not adequately predicted by the theory suggesting that the turbulence model used did not respond to the rapidly changing flow conditions in a physically realistic way.