Aeroelastic Limit Cycle Oscillations Due to Multi-element Control Surface with Freeplay

Single control surface (CS) freeplay has been extensively investigated in the aeroelastic literature and several studies describe its effect on the limit cycle oscillations (LCO). Airworthiness regulations establish that this discontinuous nonlinearity needs to be considered in both CS and trailing-edge tab, if the latter one exists. In this context, the present study investigates the effects of freeplay from both CS and tab on the LCO. The four-degree-of-freedom typical section is considered, highlighting the main differences when compared with the freeplay of a single trailing-edge surface. The results show that higher amplitudes are identified for this configuration when compared to the classical case.