Photonic additives have been investigated as a means to enhance the efficiency of thermal protection systems (TPS) against the adverse effects of thermal radiation. State-of-the-art TPS consist of carbon fibers embedded in a phenolic resin matrix. During operation, the TPS is consumed because it is exposed to an excess heat flux, a large fraction of which is due to thermal radiation. Here, we show that a properly modeled and designed additive-impregnated TPS can block a considerable part of this heat influx and quantify how different control parameters, in particular the additives’ amount, placement and alignment, influence the achieved photonic enhancement. More specifically, the intrinsic reflectivity of 8.5% of a conventional TPS can been improved to values exceeding 85% by controllably inserting additives, consisting of a Ta/[SiO₂/TiO₂]₆ heterostructure, here referred to as Type 1, an ideal, optimized, high and broadband reflector. Nevertheless, even simple, commercially available additives composed of TiO₂/Al₂O₃/TiO₂, here referred to as Type 2, provide a high reflectivity enhancement with values of up to 76%, when used in larger quantities. The simulations of this work are based on the Monte Carlo Ray Tracing (MCRT) method. The MCRT simulation method has been validated against experiment, using the structure and experiments from a literature reference. Our analysis method allows one to design and model the performance of photonically enhanced TPS that operate in high-flux, radiative conditions, like those expected in future aerospace re-entry missions or next-generation, gas turbines and thermophotovoltaic plants and provides a viable option for efficiently enhancing a TPS.

光子添加剂已被研究作为一种提高热保护系统 (TPS) 效率的手段，以抵御热辐射的不利影响。最先进的 TPS 由嵌入酚醛树脂基质中的碳纤维组成。在运行期间，TPS 会被消耗，因为它暴露于过多的热通量，其中很大一部分是由于热辐射。在这里，我们展示了正确建模和设计的添加剂浸渍 TPS 可以阻止相当一部分热量流入，并量化不同的控制参数，特别是添加剂的数量、位置和排列，如何影响实现的光子增强。更具体地说，通过可控地插入由 Ta/[SiO₂ /TiO ₂ ] ₆异质结构，这里称为类型1，一种理想的、优化的、高宽带反射器。然而，即使是由 TiO ₂ /Al ₂ O ₃ /TiO ₂组成的简单的市售添加剂，此处称为类型 2，当大量使用时，可提供高达 76% 的高反射率增强。这项工作的模拟基于蒙特卡罗光线追踪 (MCRT) 方法。MCRT 模拟方法已通过实验验证，使用参考文献中的结构和实验。我们的分析方法允许人们设计和建模在高通量、辐射条件下运行的光子增强 TPS 的性能，就像未来航空航天再入任务或下一代燃气轮机和热光伏电站中预期的那样，并提供一种可行的选择用于有效地增强 TPS。