Advancements in Aerodynamic Shape Optimization with Hybrid Laminar Flow Control for Infinite Swept and Finite Wings at Cruise Conditions

Hybrid laminar flow control (HLFC) offers a promising approach to reducing drag by extending laminar flow regions on wings through the combination of passive shaping and active boundary-layer suction. In this work, a suction boundary condition is integrated into a Reynolds-averaged Navier–Stokes aerodynamic shape optimization framework coupled with the SA-sLM2015cc local correlation-based transition model. The implementation is first validated against benchmark cases, including flat-plate flow and NACA 64A010 airfoil experiments, demonstrating accurate prediction of laminar-to-turbulent transition under varying suction intensities. Lift-constrained drag minimization is performed with natural laminar flow, i.e. without suction, for infinite swept wings under estimated Airbus A340 operating conditions. Applying suction upstream of the transition location on the optimized geometries delays transition, yielding drag reductions of up to 15% relative to fully-turbulent optimized geometries. The updated transition location was determined and suction was also applied just upstream of this location, yielding 19% drag reduction compared to a turbulent optimized geometry.