Accession Number:

ADA169531

Title:

PNS (Parabolized Navier-Stokes) for Spinning Shell at Moderate Angles of Attack and for Long L/D Finned Projectiles.

Descriptive Note:

Final rept.,

Corporate Author:

ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD

Report Date:

1986-06-01

Pagination or Media Count:

49.0

Abstract:

The thin-layer Parabolized Navier Stokes PNS computational technique is applied to calculate the three-dimensional viscous flow about two types of projectiles 1 a standard shell configuration at moderate angle of attack with a region of lee side crossflow separation and 2 long LD finned projectiles. Results for the shell configuration are obtained using the algebraic turbulence model for Baldwin and Lomax with and without modifications that more properly account for regions of lee side crossflow separation. Comparisons are made with wind tunnel pressure and force measurements as well as boundary layer velocity data. For a nonspinning shell, significant improvement in prediction of surface pressure at 6.3 degrees angle of attack is found by applying the modified model. For spinning shell, good agreement between the numerical predictions and the experimental Magnus force and velocity profile data is found only if the turbulence model modification strategy is relaxed. Results are then presented for the LD finned projectile configurations. Computed pitch-plane aerodynamic coefficients for long LD axisymmetric forebodies 20-35 calibers are presented and compared with wind tunnel data. The results, which are in reasonable agreement with the experimental data, demonstrate the importance of viscous effects on the pitch plane aerodynamics for long LD bodies. Computations for a complete finned body configuration are presented and comparison made with inviscid code predictions and aerodynamic range data. Good agreement between the PNS computations, the inviscid predictions, and the range data is observed.

Subject Categories:

  • Armor
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE