Shear Ablation Behavior and Mechanism of Liquid Silicone Rubber Composites at Different Ablation Angles and Distances
Liwei Yan, Yuan Wang, Long Ni, Haoruo Zhang, Shengtai Zhou, Mei Liang, Huawei Zou, Yang Chen, Zhengguang Heng
Abstract
The shear ablation behavior of liquid silicone rubber composites (LSRCs) was examined using an oxyacetylene flame at different ablation angles and ablation distances. Computational fluid dynamic (CFD) simulations were conducted to determine the flow field of oxyacetylene flame at different ablation angles. Results indicated that the ablation morphology of LSRCs was significantly different at different ablation angles, and the centrally symmetrical structure of ablation pits under normal ablation turned to be an eccentric asymmetric distribution under shear ablation. Linear ablation rates were greatly augmented when the ablation distance was lower than the critical value where the shear force is dominant. The accelerated ablation rate and the asymmetric ablation craters were mainly attributed to the powerful mechanical denudation induced by an intense gas flow. The disruption of continuity of the molten liquid layer and further loss initiated a more rapid elimination of the ablated boundary. This work elaborated the influence of the ablation angle on the ablation behavior of LSRCs, which provided a reference for the design of an insulation material targeted for more serious service environments.