In the realm of unsteady Conjugate Heat Transfer (CHT) simulations, as those in combustion chambers, a significant challenge arises: how to effectively address both the computational cost and the inherent stiffness resulting from the notable disparity in time scales between fluid and solid domains, especially in the multiple fluid–solid coupled systems, such as the combustor liners equipped with Thermal Barrier Coating (TBC). While the current desynchronizing coupling scheme greatly improves the computational efficiency, it consistently amplifies the fluctuation amplitudes of the fluid–solid interface temperature. To overcome the compromised solution accuracy observed in the desynchronizing scheme, the present study introduces a multi-medium coupling scheme incorporating time-scale decomposition method and fluid–solid interface coupling strategy. This proposed scheme is primarily designed to accurately and efficiently reach the permanent state of transient thermal fluid–solid simulations within multi-medium systems, focusing on accelerated coupling for both time-averaged (long timescales) and fluctuating (short timescales) thermal components rather than aiming for a fully accurate transient response of metals. The scheme has been validated through a series of test cases, which are simplified representations derived from real engine combustors. The results show that the proposed scheme achieves a speed-up factor of 5 for the single layer TBC scenario and 2.5 for the double layer TBC scenario compared to the synchronizing scheme, and it closely aligns with the synchronizing solution under the smallest relative errors, compared to those desynchronizing schemes. Furthermore, the proposed scheme maintains both efficiency and accuracy in scenarios with random disturbances, demonstrating its capability of simulating CHT problems under extreme flow conditions and multiple mediums.

中文翻译：

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多媒体系统瞬态热流固耦合模拟的加速时标分解算法

在非稳态共轭传热 (CHT) 模拟领域，就像燃烧室中的模拟一样，出现了一个重大挑战：如何有效解决由于流体和固体域之间时间尺度的显着差异而导致的计算成本和固有刚度，特别是在多个流固耦合系统中，例如配备热障涂层（TBC）的燃烧室衬里。虽然当前的去同步耦合方案极大地提高了计算效率，但它始终放大了流固界面温度的波动幅度。为了克服去同步方案中观察到的求解精度受损的问题，本研究引入了一种结合时间尺度分解方法和流固界面耦合策略的多介质耦合方案。该方案主要旨在准确有效地达到多媒体系统内瞬态热流体-固体模拟的永久状态，重点关注时间平均（长时间尺度）和波动（短时间尺度）热组件的加速耦合，而不是旨在获得完全准确的金属瞬态响应。该方案已通过一系列测试用例得到验证，这些测试用例是来自真实发动机燃烧室的简化表示。结果表明，与同步方案相比，该方案在单层TBC场景下实现了5倍的加速因子，在双层TBC场景下实现了2.5倍的加速因子，并且在最小相对误差下与同步方案紧密结合。那些去同步的方案。此外，该方案在随机扰动的情况下保持了效率和准确性，展示了其在极端流动条件和多种介质下模拟CHT问题的能力。