Theoretical and Experimental Analysis of Asbestos Phenolic Ablative Insulation

Document Type : Research Article

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Abstract

One of the major challenges in high-speed flights is aerodynamic heating. This is why thermal protection system (TPS) is being used. One of the main components of TPS is ablative insulation. In present study, one-dimensional theoretical and experimental analysis of ablative insulations have been done. Phenolic resins with maximum thermal destruction efficiency are being used in charring ablative insulations. When an ablative insulation is exposed to heat flux, its surface gets warmer and as the destruction begins, it produced gases to go out and do cooling. Governing equations of these phenomena have been discretized by the finite difference method and have been solved transient and implicitly. Thermophysical properties have been evaluated by nominal curves and Pyrolysis constants have been obtained by / through the thermochemical reactions. Validation of numerical solution has been done by oxy-acetylene test. By increasing the time, the difference between numerical and experimental results increases. One reason for difference between results could be 1D-modeling, where all of the actual 3D energy is accumulated in one dimension in the numerical solution. Nonetheless, there is good agreement between numerical and experimental results and the average of absolute errors is 7.54%.

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[1] Goodman, T. R. , “The heat balance integral and its application to problems involving a change of phase”, Transactions of ASME, Vol. 80, pp. 315- 322, 1958
[2] Altman, M., “Some aspects of the melting solution for a semi infinite slab”, Chemical engineering progress symposium series, Vol. 57, pp. 16- 23, 1958
[3] Zien, T. F., “Integral solution of ablation problems with time dependant heat flux”, AIAA journal, Vol. 16, pp. 1287- 1295, 1978.
[4] Chung, B. T. F.; Chang, T. Y.; Hsiao, J. S.; Chang, C. I., “Heat transfer with ablation in a half-space subjected to time-variant heat flux”, ASME winter annual meeting, paper No.81-WA/HT- 34, 1981.
[5] Blackwell, B. F., “Numerical prediction of one-dimensional ablation using a finite control volume procedure with exponential differencing”, Numerical heat transfer, Vol. 14, pp. 17- 34, 2003.
[6] Potts, R. L., “Hybrid integral/quasi-steady solution of charring ablation”, AIAA paper 94- 2089, 1994.
[7] Fen, R. H.; Gang, D., “A theoretical calculation method of local ablation in region of shock-boundary layer interaction”, AIAA paper 80- 1688, 1990.
[8] Walber, F. B.; Marcia, B. H. M, “Approximate analytical solution for one-dimensional ablation with time-variable heat flux”, 36th AIAA Thermophysics conference, 2003.
[9] ASTM standard, E285-80, “Standard test method for oxyacetylene ablation testing of thermal insulation material”, 2002.
[10] Amar, A. J., “Modeling of One-Dimensional Ablation with Porous Flow Using Finite Control Volume Procedure”, MSc thesis, North Carolina state university, 2006.
[11] Yongkang, L., “Phenolic Resin in Heatshields”, 36th International SAMPE Symposium April, 1, 1991.
[12] Stover, E. R.; Juneau P. W.; Brazel, J. P, “Ablative Materials”, Vol. 1, pp. 10- 26, 1978.
[13] Полежаев, Ю. В. , Юревич, Ф. Б, “Тепловая защита”, Москва, Энергия, 392c, 1976.
Amirkabir Journal of Mechanical Engineering
Volume 47, Issue 1 - Serial Number 1
October 2015
Pages 101-109

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