Numerical Simulation Of Steady Supersonic Flow Over An Ogive Cylinder Boattail Body

Numerical Simulation of Steady Supersonic Flow Over an Ogive Cylinder Boattail Body

A recently reported Parabolized Navier-Stokes code has been employed to compute the supersonic flow field surrounding an ogive-cylinder-boattail body at incidence. The computations were performed for flow conditions where an extensive series of experimental surface pressure and turbulent boundary-layer profile measurements had been obtained. Comparison between the computational results and experimental measurements for angles of attack up to 6 deg. show excellent agreement. At angles greater than 6 deg. discrepancies are observed which are tentatively attributed to three-dimensional turbulence modeling errors. (Author).

Some Aerodynamic Characteristics of a Projectile Shape with a Nonaxisymmetric Boattail at Mach Numbers of 0.91 and 3.02

Some aerodynamic properties of a projectile shape with a nonaxisymmetric boattail are presented. The boattail is formed by machining three flat surfaces which are equally spaced and inclined seven degrees to the model axis. Aerodynamic forces obtained by strain-gage balance measurements are presented for angles of attack up to 15 degrees and for various roll orientation of the model. Because the effect of roll orientation on coefficient data is quite small, coefficients are presented in incremental form so that the effect of roll can be graphically amplified. A limited quantity of the data is compared to computational results for Mach 3.02. The results of this study support previous studies which show that nonaxisymmetric boattail shapes can improve the static stability of projectiles.

Technical Abstract Bulletin