MODELING AND SIMULATION OF AERODYNAMIC NOSECONE ABLATION

This work deals with the modeling and simulation of ablation in aerodynamic heating of a highspeed projectile. Generic projectiles with plastic hollow nosecones (for housing the radar system) in supersonic flight are considered for the purpose of developing efficient designs for high-speed projectiles. Computations are performed using the shear-stress transport (SST) k-omega model that is widely used for many aerodynamic applications. The time-Averaged equations of motion and energy are solved using the modeled form of transport equations for the turbulence kinetic energy and specific turbulent dissipation rate with an efficient finite-volume algorithm. The possible melting and phase change during flight conditions are modeled in the context projectile design. Modeling liquidized material flow by ablation along the solid surface of the supersonic projectile uses a multiphase treatment of the plastic nosecone melt material under influence of the high velocity gas. The model considers stratified/free-surface flow in which two immiscible fluids are separated by a clearly defined interface. Computational findings show that a commonly used plastic nosecone material would ablate during high-speed flights. The magnitude of ablation, changes to the shape and resultant aerodynamic penalty for the projectile are quantified and discussed.