Transformative Calibration Method for Prediction of Surface Heat Flux

CBET-1234419PI(S)：J.I.Frankel和M.Keyhani田纳西-诺克斯维尔大学(UTK)提出了一种基于深度温度测量来预测地表热通量的变革性定标方法。为了减轻传感器在恶劣环境中的直接暴露，通常需要测量试件的内部位置。提出了一种基于物理和数学推导的校准框架，用于研究航空航天应用中出现的各种加热条件。这项研究以互补的方式整合了分析和实验活动，以验证在大温度范围和各种供暖情景下进行反向预测的科学性。该校准概念大大减少了系统误差，因为它不需要指定探头位置、探头特性和热物理性质。完整的系统特性内在地包含在所得到的校准方程中。由于不适定，提出了一种新的正则化方法来稳定数值预报。不适定问题对采集到的数据中的噪声高度敏感。这种新的本地-未来时间方法利用校准方程的行为来提取最优预测。这种独特的特性可能是新的校准配方的结果。将使用都在UTK维护的电热夹层设备或高功率激光设备来对所导出的校准方程进行实验验证。多维和多区域几何；以及各向同性和正交异性材料样品将被研究，因为它们在航空航天科学中对于与高超声速飞行器外部蒙皮和高超声速燃烧室表面相关的热保护系统具有重要意义。这项研究的重点是开发能够利用深度温度数据准确预测表面热流的方法，用于材料评估和定位转变。该项目将通过以产生校准方程为基础的综合分析和实验方法，为反问题提供新的见解。这与将实验数据视为输入到估计表面条件的数值方法的传统理论形成了鲜明对比。因此，拟议的概念可以扩展到影响许多物理和工程领域的大类或领域的问题，包括火和燃烧科学、金属铸造、晶体生长和焊接科学。此外，几个欧洲机构将参与总体计划，表明这种方法在未来高速航空研究中的优点和意义。

CBET-1234419PI(s): J.I. Frankel and M. KeyhaniUniversity of Tennessee-Knoxville (UTK)A transformative calibration methodology is proposed for predicting the surface heat flux based on in-depth temperature measurements. Instrumenting interior locations of a test article is often necessary in order to alleviate the sensor's direct exposure to a hostile environment. A physics based and mathematically derived calibration framework is proposed for studying a variety of heating conditions that appear in aerospace applications. This investigation integrates analytical and experimental activities in a complementary manner for verifying the science of inverse prediction over a large temperature range and under various heating scenarios. The calibration concept substantially reduces systematic errors since it does not require the specification of the probe position, probe characteristics, and thermophysical properties. Full system characterization is inherently contained in the resulting calibration equations. Being ill posed, a new regularization method is proposed for stabilizing the numerical predictions. Ill-posed problems are highly sensitive to noise in the collected data. This new, local-future time approach exploits the behavior of the calibration equation for extracting an optimal prediction. This unique characteristic may be a consequence of the novel calibration formulation. Experimental verification of the derived calibration equations will be performed using either an electrically heated sandwich facility or high-powered laser facility that are both maintained at UTK. Multidimensional and multi-regional geometries; and, isotropic and orthotropic material samples will be studied owing to their importance in the aerospace sciences for thermal protections systems associated with external skins of hypersonic vehicles and surfaces in hypersonic combustors. This research is focused on developing methodologies that can use in-depth temperature data to accurately predict the surface heat flux for material evaluation and locating transition. This project will provide new insight into inverse problems through an integrated analytical and experimental approach based on producing calibration equations. This contrasts the conventional doctrine that views experimental data as input to a numerical method for estimating the surface conditions. Hence, the proposed concept can be expanded to a large class or arena of problems affecting many areas of physics and engineering including fire and combustion sciences; metal casting, crystal growth, and welding sciences. Additionally, several European institutions will be involved in the overall plan indicating the merit and significance of the approach to future high-speed aerospace studies.