FOR 2895: Unsteady flow and interaction phenomena at high speed stall conditions

运输机在飞行包线边界处的空气动力学的特征在于复杂的相互作用和非线性瞬态空气动力学。由此产生的物理机制尚未完全理解，并且预测空气动力学特性、瞬态载荷和气动弹性行为是一个重大挑战，需要使用复杂的数值模型。尺度分辨方法在此应用中很难得到验证，需要扩展到更高的雷诺数，以便在考虑所有物理效应的情况下进行高分辨率模拟。除了缺乏高分辨率的流场测量来研究基本的物理机制外，对于高的、与飞行相关的雷诺数，几乎没有科学上可用的和足够详细的完整构型测量。2895研究组的主要目标是对运输机高速失速中尚未解决的物理问题进行全面研究，扩展和限定用于这一应用的数值方法，以及用降阶模型对非定常流和非线性空气动力学进行建模。为了描述整个布局的气动效应，必须理解局部物理机制和相互作用。通过对流场不同部分的流动物理学进行协调的数值和实验研究，并结合对全飞机构型的相应研究，将获得知识。该研究小组由七个子项目组成，对机翼上侧的抖振、分离尾流的发展及其与尾翼的相互作用进行了详细的研究。这些研究将在空中客车XRF-1运输机配置上进行，其中超高旁通短舱将被集成以研究发动机影响和局部相互作用。为了能够测量与飞行相关的雷诺数，实验将在低温风洞ETW中进行，由HGF和DLR提供资金。由此产生的数值和实验数据库将用于建模和推导的降阶模型和流动物理研究。此外，FOR 2895还将在一般纵列机翼构型上，在减小的雷诺数下，对基本流动现象进行数值和实验研究，这允许对边界层的相关尺度进行空间上更高分辨率的测量。

The aerodynamics of transport aircraft at the borders of the flight envelope are characterized by complex interactions and non-linear, transient aerodynamics. The resulting physical mechanisms are not fully understood and a prediction of aerodynamic properties, transient loads and aeroelastic behavior is a major challenge and requires the use of complex numerical models. Scale resolving methods are hardly validated for this application and need to be extended for higher Reynolds numbers in order to perform high-resolution simulations taking into account all physical effects. Apart from a lack of high resolution flow field measurements to study the underlying physical mechanisms, there are few scientifically usable and sufficiently detailed measurements of complete configurations for high, flight-relevant Reynolds numbers. The main goals of the research group 2895 are the comprehensive investigation of the unresolved physical issues in the high-speed stall of transport aircraft, the extension and qualification of numerical methods for this application and the modelling of unsteady flow and nonlinear aerodynamics with reduced order models. The local physical mechanisms and interactions must be understood to achieve a description of the aerodynamic effects for the complete configuration. The knowledge gain will be achieved by coordinated numerical and experimental studies of the flow physics in different parts of the flow field combined with corresponding investigations on a full aircraft configuration. The research group, which is organized in seven subprojects, carries out detailed studies on the buffet on the upper side of the wing, the development of the separated wake and its interaction with the tail plane. These studies will be carried out on the Airbus XRF-1 transport aircraft configuration, in which an ultra-high bypass nacelle will be integrated to study engine influences and local interactions. In order to enable measurements up to flight-relevant Reynolds numbers, the experiments will be conducted in the cryogenic wind tunnel ETW with funding from the HGF and DLR. The resulting numerical and experimental data base will be used for modelling and derivation of reduced order models and for flow physics studies. In addition, the fundamental flow phenomena will be studied numerically and experimentally by FOR 2895 on a generic tandem wing configuration at reduced Reynolds number, which allows spatially higher resolved measurements in relation to the relevant scales of the boundary layers.