Passive nosetip technology (PANT) program. Volume 18: Nosetip analyses using the EROS computer code

The results of nosetip response calculations using the newly-developed, EROsion Shape (EROS) computer code are documented. The code enables the evaluation of nosetip coupled erosion and ablation and shape change for arbitrary materials including fine weave carbon/carbon, polycrystalline graphite, and reinforced phenolics. Transient heat conduction is also treated through an innovative explicit differencing scheme. Calculations are presented for wind tunnel test environments, ICBM clear air flight conditions, and Terrier-Recruit sounding rocket flight conditions. In the analysis matrix, modeling techniques are varied to identify response sensitivity to modeling uncertainties. The primary conclusions are that: Transition altitude and overall recession of ICBM nosetips in clear air are critically sensitive to material roughness characteristics. Hydrometeor impacts cause significant nosetip erosion mass loss and increased surface thermochemical mass loss.