DDDAS-SEP: Application of DDDAS to Assessment of Thermal Systems Using Combined Experiment and Simulation

该项目将应用动态数据驱动应用系统(DDDAS)方法，通过实验和模拟相结合的方式评估流体-热力系统。涉及流体-热力系统的工程应用的特点是复杂的三维流动，关键子系统中的边界条件知识不完全，实验诊断的途径有限。一个例子是涡扇发动机中的燃烧室，其中燃烧室表面上的热边界条件是先验未知的(即，表面温度分布未知)，并且用于光学诊断的途径受到严重限制。基于DDDAS的方法将实验和模拟相结合，以实现对流体-热系统的评估；特别是确定合理精度的表面温度分布。具体的应用是正常喷射到亚音速或超音速平衡湍流边界层中的湍流射流。通过与燃烧器或炉子的类比，假设实验诊断仅限于受限区域内的光学测量(具体而言，是不同波长的二极管激光吸光度)(以模拟实际配置中的有限访问，例如燃烧器)。模拟将使用三维雷诺平均的N-S方程和k-e湍流模型。所提出的基于DDDAS的流体-热力系统的实验和仿真评估方法在工程系统(如化学和生化工程、土木工程等)中具有潜在的更广泛的应用前景。

The project will apply the Dynamic Data Driven Applications Systems (DDDAS) methodology for assessment of fluid-thermal systems using combined experiment and simulation. Engineering applications involving fluid-thermal systems are characterized by complex three-dimensional flows with incomplete knowledge of boundary conditions in critical subsystems and limited access for experimental diagnostics. An example is the combustor in a turbofan engine wherein the thermal boundary conditions on the combustor can surface are not known a priori (i.e., the surface temperature distribution is not known) and access for optical diagnostics is severely limited. The DDDAS-based methodology synergizes experiment and simulation to achieve an assessment of the fluid-thermal system; in particular, to determine the surface temperature distribution to a reasonable level of accuracy. The specific application is a turbulent jet injected normally into a subsonic or supersonic equilibrium turbulent boundary layer. By analogy to a combustor or furnace, the experimental diagnostics are assumed to be limited to optical measurements (specifically, diode laser absorbance at various wavelengths) within a restricted region (to simulate limited access in the actual configuration, e.g., combustor). Simulations will be performed using the three-dimensional Reynolds-averaged Navier-Stokes equations with the k-e model of turbulence. Both non-reacting and reacting flows will be considered.The proposed DDDAS-based methodology for assessment of fluid-thermal systems using experiment and simulation has potentially broader applications in engineering systems (e.g., chemical and biochemical engineering, civil engineering, etc).