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Wednesday, May 05, 2010, Moor Room 11:40 AM Modeling and Simulation 2 |
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Predicting the thermal conductivity of AlSi/polyester abradable coatings: effects of the numerical method |
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Rodolphe Bolot* / ICB-UBFC, LERMPS-UTBM, France Jean-Louis Seichepine / LERMPS-UTBM, France Jiang Hao Qiao/ LERMPS-UTBM, France Christian Coddet/ LERMPS-UTBM, France |
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The final target of this study was to achieve a better understanding of the behaviour of thermally sprayed abradable seals such as AlSi/polyester composites. These coatings are used as seals between the static and rotating parts in gas turbine applications. The machinability of the composite coatings during the friction of the blades depends on their mechanical and thermal effective properties. In order to predict these properties from micrographs, numerical studies have been performed with different software packages such as OOF developed by NIST or TS2C developed at the UTBM. In 2008, differences were reported concerning the prediction of the effective thermal conductivity obtained with the two codes. In the present paper, it is shown that a particular attention must be paid to the mathematical formulation of the problem. In particular, results obtained with a finite difference method using a cell centre approach or a nodal approach, allow explaining the discrepancies previously noticed. A comparison of the predictions of the computed effective thermal conductivities is thus proposed for different codes and different meshing methods. This study is part of the NEWAC project, funded by the European Commission under the 6th RTD Framework programme (FP6). |