Fragment Acceleration Modeling for Pressurized Tank Burst

Abstract

As part of comprehensive efforts to develop physics-based risk assessment techniques for space systems at NASA, coupled computational fluid and rigid-body dynamic simulations are carried out to investigate the flow mechanisms that accelerate tank fragments in bursting pressurized vessels. Simulations of several configurations are compared to analyses based on the industry-standard Baker-type explosion model, and they are used to formulate an improved version of the model. A validation against the experiment is carried out for one configuration. The standard model, which neglects an external fluid, is found to agree best with simulation results only in configurations where the internal-to-external pressure ratio is very high. An improved model introduces terms that accommodate an external fluid and better account for the pressure at the fragment wall. A physics-based analysis is critical in increasing the model’s range of applicability. The improved tank burst model can be used to produce more accurate risk assessments of space vehicle failure modes that involve high-speed debris, such as exploding propellant tanks and bursting rocket engines.