Base drag reduction due to riblets on a gaw (2) airfoil

Results from an experimental study to determine the effect of riblets on the base drag of a GAW(2) airfoil at low speeds are presented. Riblet films (3M Co.,USA) of groove height 0.076 mm and 0.152 mm were employed in the study. Measurements made consisted of surface pressure distributions, base pressure and total drag using the wake survey method in the incidence range of -2 to 6 deg. Results show that riblets provide base drag reduction of about 0.7 % of the total drag, in addition to significant viscous drag reduction