Study of Vortex Aerodynamics for Compound Delta Wings by CFD and Wind Tunnel Testing : Investigation of a pitch divergence problem

Sammanfattning

The SOAR2 is a modern aircraft with a chined forebody and a double deltawing configuration. It is originally developed by Saab as a loyal wing man,but published as an open research model. The vortices coming off the forebodyand wings interact with the tailfins at high angles of attack, causing a pitch-up divergence. This phenomenon is investigated through wind tunnel loadexperiments, flowfield mapping, and numerical simulations.Three potential solutions are tested: a smoothing of the wing kink, addinga negative swept leading edge root extension (NLERX), and a combination ofthe two. Both quantitative moment analyses and qualitative flow field analysesare conducted.It is found that a smooth kink transition has a positive effect on the pitchmoment divergence angle, with minimal effect on other parameters.