NLF wing design by adjoint method and automatic transition prediction

This dissertation describes the application of optimization technique based on control theory for natural-laminar flow airfoil and wing design in viscous compressible flow modeled by the RANS equations. A transition prediction module which consists of a boundary layer method and two eN-database methods for Tollmien-Schlichting and crossflow instabilities are coupled with flow solver to predict and prescribe transition locations automatically. Results of the optimization will demonstrate that an airfoil can be designed to have the desired favorable pressure distribution for laminar flow and the new airfoil can be redesigned for higher Mach number for performance benefits while still maintaining reasonable amount of laminar flow. For 3D wing, the redesigned wing will demonstrate an overall improvement over wide range of Mach numbers. The results prove the feasibility and necessary of incorporating laminar-turbulent transition prediction with flow solver in natural laminar-flow airfoil and wing design.