Ablation modeling of subliming ablator of a blunt-nosed body under aerodynamic heating

The purpose of this study is to predict shape change due to ablation and to find temperature distribution of the thermal protection system of a supersonic vehicle under aerodynamic heating by using finite element method. A subliming ablative material is used as thermal protection material. Required material properties for the ablation analyses are found by using TGA (Thermogravimetric Analysis) thermal analysis techniques. Moreover, oxyacetylene ablation tests are performed for the subliming ablative specimens and measured recession values are compared with the analytically calculated values. Maximum difference between experimental results and analytical results is observed as 3%. For the finite element analyses, ANSYS Software is used. A numerical algorithm is developed by using programming language APDL (ANSYS Parametric Design Language) and element kill feature of ANSYS is used for ablation simulation. Numerical algorithm is applied to test specimens and blunt-nosed section of the supersonic missile. Recession history of the nose section is obtained during flight period.