Experimental Design for the Validation of Extended Hybrid Laminar Flow Control and Transition Prediction in Complex 3D Flows

Kurzfassung

Transition prediction in complex three-dimensional flows is challenging due to non-ideal conditions, which are further complicated by the influence of suction. Consequently, high-quality measurement data for complex flows are essential to validate the numerical models employed in the aerodynamic design of swept wings with active flow control. However, existing public data primarily focus on 2.5D flows, neglecting meaningful experimental data for 2.5D and 3D flows with suction, especially in adverse pressure gradients. To address this gap, a wind tunnel campaign will be conducted using a generic wing with gradually increasing sweep angles and a suction insert. This model is used to validate the suction in the adverse pressure gradient and generate experimental data for numerical model validation. It allows for a thorough investigation of Tollmien-Schlichting and cross flow instability amplification rates representative of free flight conditions and their interaction with the suction panel by varying inflow conditions and the angle of attack. The model also features a section with highly three-dimensional flow, leading to a rapidly changing transition line along the span, which facilitates model validation and insight into transition mechanisms. The large scale of the model permits chord Reynolds numbers of up to 5 million, enabling effective measurements.