Influence of the dimple size and spacing for passive flow control in blended wing body aerodynamics: a CFD investigation

Blended wing body (BWB) aircraft have re-emerged as a research focus owing to their potential for enhanced aerodynamic efficiency and fuel economy. This study investigates the application of passively integrated dimples to further optimize BWB performance using computational fluid dynamics (CFD) simulations. An incompressible Reynolds-averaged Navier–Stokes solver coupled with the k–ω shear stress transport turbulence model was employed to characterize turbulent airflow and estimate the associated aerodynamic forces. The objective was to investigate the effect of various non-dimensional diameter ratios at different non-dimensional spanwise pitch distance ratios of dimples placed on the suction and pressure surfaces of the BWB wings. Simulations were performed at a free-stream velocity of 50 m s−1, and the aerodynamic characteristics including the drag coefficient (CD), lift coefficient (CL) and lift-to-drag (L/D) ratio were analysed. The results suggest that an optimal combination of dimple size and spacing could yield an increase of up to 8.14% in the L/D ratio compared to an unmodified BWB wing surface. These findings underscore the significance of optimizing dimple size and spacing as crucial design parameters for enhancing BWB aerodynamic performance through passive flow control.