The Effect of Inboard and Outboard Wing Sweep Angles to Lift-to-Drag Ratio of a Compound Wing-Body Using Panel Code

Compound wing consists of inboard and outboard wings and it is essential to look at these sweep angles' impact to aerodynamic performance. In this paper, the effect of inboard and outboard wing leading-edge sweep angle to lift-to-drag ratio of compound wing-body aircraft is investigated. The method of investigating aerodynamics is via computation using Panel Code in OpenVSP software combine with calculation of parasite drag coefficient based on Blasius' friction coefficient equations and Torenbeek's form factor. Baseline-IX BWB becomes the base design of this study where there are a total of ten inboard and outboard sweep angle cases. Comparison between panel code computation and wind tunnel experiment results shows similar trend and magnitude up to 10.0 deg. angle of attack. The trend of all cases is similar to the original case where maximum L/Ds for almost all cases also occur at alpha = +6.0 deg. The cases where Li = 45 deg. have the highest lift-to-drag ratio, followed by Li = 30 deg. and the lowest are for Li = 15 deg. No explanation behind the trend can be concluded unless detail visualization experiments and computations are executed.