This paper focuses on optimizing the planform and vortex generators (VGs) to improve longitudinal stability of the lambda-wing aircraft by alleviating pitchup. The optimizations are performed in two stages using a Reynolds-averaged Navier–Stokes (RANS) solver that can accurately capture the vortical flow structure, affecting the pitchup. First, the planform configuration is optimized to minimize the rise in the pitching moment while maintaining aerodynamic and stealth performances. The designed planform delays the pitchup by 4 deg and increases the usable lift by 31% due to the leading-edge vortex (LEV) flow over the outboard wing. Second, the VGs are installed and optimized to reduce the sudden increase in the pitching moment at high angles of attack. The designed VGs partially eliminate the separated flow and recover the LEV on the outboard wing, suppressing the radical change in the pitching moment by 75%. Some quantitative difference in aerodynamic coefficients is observed in unsteady RANS computations, but the vortical flow unsteadiness minimally affects the flow structure, and the stability improvement remains over 80%. Overall, the generation and sustainability of the LEV are critical aerodynamic factors to secure longitudinal stability in designing the lambda-wing aircraft.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Design Optimization of Lambda-Wing Planform and Vortex Generators for Longitudinal Instability Alleviation


    Contributors:
    Lee, Seonguk (author) / Kim, Chongam (author)

    Published in:

    Journal of Aircraft ; 61 , 2 ; 503-514


    Publication date :

    2024-03-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Load Alleviation and Wing Planform Optimization for Fuel Efficient Conceptual Aircraft Design

    Krengel, Markus Dino / Deutsches Zentrum für Luft- und Raumfahrt - Institut für Aerodynamik und Strömungstechnik | TIBKAT | 2025

    Free access

    AERO-STRUCTURAL WING PLANFORM OPTIMIZATION

    Leoviriyakit, K. / Jameson, A. / American Institute of Aeronautics and Astronautics | British Library Conference Proceedings | 2004



    Wing Planform Design Optimization for Reusable Launch Vehicle

    Manokaran, K. / Vidya, G. / Sivaramakrishnan, A. E. et al. | AIAA | 2009