A capability of measuring in-flight base pressure on an artillery-fired projectile has been developed. A key part of this development was the design and development of an environment-driven projectile base-sealing mechanism that protects the sensitive in-flight base pressure instrumentation during gun chamber and tube exit. Base pressure was measured on two 155-mm projectile configurations of current interest, and the flight data compare well with ground-base measurements and computations for the same or similar configurations. The most significant comparison between flight test data and those obtained in the wind tunnel naturally lies with those from models of the actual projectiles. A comparison using the data in drag coefficient form shows that the flight test base pressure was higher subsonically, lower transonically, and slightly lower supersonically. The primary cause of differences in base pressure is probably the model support interference effects. Also, spin effects in flight test might contribute - especially transonically and subsonically - because of ''excess-spin'' effects. (ERA citation 12:041603)
Measurement of Inflight Base Pressure on an Artillery-Fired Projectile
1987
16 pages
Report
No indication
English