Three Dimensional Flow Calculations for a Projectile with Standard and Dome Bases
Abstract
Test firings of the 155mm XM825 artillery projectile have shown that its flight performance was affected by configurational changes to the base affected the flight behavior did not exist. A computational study has been made for the two different base cavity configurations which were flight tested. Flow field computations have been performed at 0.8 < M < 1.5 and alpha = 4.0 degrees using a recently developed 3D Navier-Stokes code. The computed results show the qualitative features of the base region flow filed for the two base cavities. The base changes are found to alter the recirculation patterns in the wake which in turn affect the expansion at the base corner. These changes in the flow structure contribute to small changes in the base pressure. Aerodynamic force and moment coefficients have been obtained from the computed pressures and are presented as a function of Mach number. Computed results show small differences in normal force and pitching moment coefficients similar to that found in the range data. Keywords: Numerical computations, Angle of attack, Moment coefficients, Transonic, Base cavities.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1990
- Accession Number
- ADA227282
Entities
People
- Charles J. Nietubicz
- Jubaraj Sahu
Organizations
- Ballistic Research Laboratory