Modeling and Computation of Aerodynamic Nosecone Ablation

This presentation involves the modeling and simulation of nosecone ablation due to aerodynamic heating of a projectile in highspeed flight. 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 an efficient anisotropic turbulence model that has wide applicability for 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. The liquidized material flow due to ablation along the solid surface of the projectile in supersonic flow uses a multiphase model of the plastic nosecone melt material under influence of the high velocity gas. In this context, the stratified/free-surface flow in which two immiscible fluids are separated by a clearly defined interface is prescribed by the model. Computational findings show that commonly used plastic nosecone 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.