Flow Visualization of Steady and Transient Combustion in a 12O-mm Ram Accelerator

摘要

A technique to visualize transient and steady combustion phenomena in ramaccelerators using sacrificial transparent acrylic chambers is demonstrated. This technique allows the normal operating environment of ram accelerators to be very closely approximated. Using this technique, details of the environment during the transient starting phase as the projectile enters the accelerator and the obtrurator is discarded are seen for the first time. In addition, steady or running combustion around the projectile after the obtrurator has been shed is captured. These flow visualizations are shown to be useful in validating computational fluid dynamics codes and in providing guidance in reducing projectile unstarts while increasing initial accelerator performance.