30. Scalloped Morphologies of Ablated Materials
- Edgar Lara-Curzio
Published Online: 26 MAR 2008
Copyright © 2005 The American Ceramics Society
Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2
How to Cite
Vignoles, G. L., Goyhénèche, J.-M., Duffa, G., Velghe, A., Nguyen-Bui, N. T.-H., Dubroca, B. and Aspa, Y. (2005) Scalloped Morphologies of Ablated Materials, in Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2 (ed E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291221.ch30
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 2005
Print ISBN: 9781574982329
Online ISBN: 9780470291221
- carbon/carbon conipositcs;
- thermal protcction;
- heat transfer;
- carboii/plicriolic resin coiriposites;
- weighted essentially non-oscillatory
In many cases, ceramic materials undergoing an ablative process (i. e. erosion, dissolution, sublimation, oxidation, etching) display a characteristic “scalloped” morphology. The length scales are not related to the ceramic microstructure, and cannot always be related to some flow pattern above the surface.
We propose a simple isothermal model, where diffusion perpendicularly to the average surface and mass loss are in competition. A Hamilton-Jacobi equation is set up, and a steady, non-trivial, analytical solution consists of intersecting circle arcs in 2D. The solution is found to be stable; the curvature radius is given by the diffusion-to-reaction ratio. A 3-dimensional isothermal simulation confirms the results and the validity of the vertical flux approximation.
Such a model could help to identify intrinsic mass-loss rate constants from morphology examination and the knowledge of gas diffusion coefficients.