Ablation Response Behavior under Different Heat Flux Environments for Liquid Silicone Rubber Composites

Ablative materials will behave differently when cruising under different hyperthermal environments. Herein, liquid silicone rubber-based composites were employed as a model system to investigate the response behavior of ablative materials under different hyperthermal environments. The computational fluid dynamics simulation was used to examine the flow field of oxyacetylene flame under different heat fluxes. Results indicated that oxyacetylene flames with different heat fluxes have almost identical temperature distributions when the ratio of O₂ and C₂H₂ is fixed, but the scouring force of the gas flow increases significantly with increasing heat flux. The ablation performance decreased when the heat flux increased from 1 to 5 MW/m², and the ablation mechanism is mainly attributed to the hybrid coupling between mechanical denudation and oxidative erosion. The ceramization reaction to form SiC tended to occur under an inert atmosphere. In addition, the carbon fibers locating on the periphery of the core region tended to assume an orientation state with the progression of the ablation process. This work elaborated the influence of heat flux intensities on the ablative behavior of liquid silicone rubber composites, which also served as a reference to developing other types of ablative materials.