Numerical research on static aeroelasticity of joined wing based on CFD/CSD coupling

With a joined wing configuration UAV as the study object, static aeroelasticity was numerically investigated by coupling CFD and CSD using loosely-coupled algorithm. CFD module adopts unsteady Reynolds Averaging N-S equations and CSD module adopts direct integration method to solve structural dynamic equation. Advancing solution in time domain, the static aeroelastic results are then obtained after convergence. Research shows that after static aeroelastic deformation of joined wing, the front wing twists negatively while the rear wing positively; the lift of front wing decreases while rear wing increases; the spanwise lift coefficient distribution differs greatly between front wing and rear wing; after static aeroelastic deformation, the lift curve slope and the longitudinal static stability derivative both increase, but large increment of nose down moment is produced; compared to single front wing, rear wing of joined wing restricts the deformation of front wing largely, leading to the loss of lift far less than single front wing; compared to single rear wing, front wing of joined wing restricts the positive torsional deformation of rear wing largely, which reduces the risk of divergence of rear wing. The results revealed the particular aeroelastic characteristics of joined wing configuration, which is to be of certain value to the aerodynamic and structural design of joined wing.