The Extended Range Cannon Artillery (ERCA) weapon system has made headlines in recent years for its ability – as its name states, to fire at an extended range. Yet, in early August, the weapon system made history by firing at the highest velocity on record with this program at Yuma Proving Ground (YPG).
As we talk about ballistic missiles and rocket systems, artillery systems can be more cost-efficient compared to using missiles and rockets. An artillery round can potentially complete the same mission at a fraction of the cost. However, with the evolution of technology, targets are getting faster, and that requires projectiles fired from artillery guns to be sent up faster through the air.
To do so, Paul Henderson, propulsion engineer with the Combat Capabilities Development Command-Armament Center (DEVCOM-AC), led the effort of designing and building the propelling charge for this high-velocity test. The YPG Ammunition Plant personnel constructed the propelling charge specific to this project based on historical data collected from the DEVCOM-AC team.
The team determined that they needed to see what happens to the propellant in the gun during ignition. The charge is inside the gun chamber when fired and unable to be observed visually. The team, therefore, developed a ballistic simulator (BSIM) to aid propulsion development and emplaced it at YPG. The BSIM tube is transparent and bursts at low pressure, but the few milliseconds of video data before it bursts are critical to the design of the propelling charge.
“We come up with different configurations of the propelling charge, and we fire it in the ballistic simulator, and we study the video. We see the transport phenomenon, we get an idea of the temperature, speed of ignition, the turbulence, and we conceptualize how we can control the burning,” Henderson explained the process. “Our goal is to have uniform burning to minimize pressure waves which damage the gun and projectile.”
The team used various ballistic computer simulations to project the outcome based on different configurations. These models help during the developmental stage and also provide insight during test fires.
During test fires, the YPG team collects data such as high-speed video, pressure, and muzzle velocity. The projectile team monitors the projectiles then compares the data collected at the test site against the data of the model.