Ablation characteristics of carbon nanotubes reinforced novolacresin nanocomposites: Experimental and simulation approach | ||
| Diyala Journal For Pure Science | ||
| Article 1, Volume 7, Issue 3, September 2011, Pages 59-70 | ||
| Author | ||
| Bahjat B. Kadhim | ||
| Abstract | ||
| Ablation rate and thermal conductivity for phenol- formaldehyde type novolac resinreinforced with single walled carbon nanotubes (SWCNTs) have been studied viaexperimental and simulation of Oxy – acetylene flame and Lee’s disc techniques respectively.Simulation programs of heat transfer in three dimensions of ablative test for novolac andnovolac nanocomposites specimens were carried out using finite difference method (FDM).Theoretical thermal conductivity was calculated according to microstructures model. Hotpresstechnique was used to prepare the nanocomposites as well as novolac specimens usingflash molds at standard conditions. Thermal conductivity results show, that the valuesincrease progressively by succession of volume fraction of SWCNTs. Ablation rate behavesinversely, where it drops at high volume fraction of SWCNTs. The thermal conductivity –ablation rate relationship, displays two mechanisms, the first, associated with the starting ofablation test, is recognized by ideal distribution of SWCNTs, which leads to good thermaldispersion due to the formation of segregated network of thermal conducting paths. Thesecond mechanism is associated with in- run ablation test recognized by shearing cracksappearance, which leads to earlier char production mechanism. Simulation thermalconductivity results, , and when it compared with the experimental results, it observed, thatthe experimental results, were located between the parallel and random direction simulationvalues of SWCNTs, which is evidenced that the additives arrangement closed to paralleldirection more than random or perpendicular direction with respect to heat flux direction.Keywords: Ablation, simulation, nanocomposites, and carbon nanotubes. | ||
| Keywords | ||
| Ablation; Simulation; Nanocomposites; Carbon Nanotubes; Novolac | ||
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