Introduction

The 4th edition (2011) of the Ablation Modeling workshop focuses on the experimental support required for the development and validation of high fidelity models in the following areas: In-depth physics and chemistry of ablation Gas-surface interactions and catalysis Roughness modeling including wall-blowing effects Ablation models inter-code calibration and validation Poster session dedicated to various existing modeling efforts The emphasis for each of the target areas is the material contribution as opposed to the aerothermodynamics. With the workshop being the first non-ITAR edition we are seeking to expose the broader (national and international) community to the particular issues involved with material response modeling under hypersonic reentry conditions in the hopes of bringing new experimental techniques to bear on the problem as well as brainstorm about the challenges faced by expanding the range of application of the existing techniques. It is also for the first time that we provided the ablation community at large with a test case for a theoretical ablator to compare results of various ablation codes and identify the role of different implementations on the predicted output results. From the perspective of TPS design, high fidelity models play a critical role since they enable anchoring of engineering codes with better represented physics and chemistry models, ability to perform sensitivity trades and identify major contributors to the overall thickness of the heatshield and lay the path for rational design for ablator materials in support of future missions as well as better use of flight data via inverse parameter estimation techniques