Dynamic wind tunnel testing of delta-wing model without support interference

The understanding of the dynamic characteristics of an airplane at high angles of attack (AOAs) is essential in making accurate predictions regarding its behavior. A magnetic suspension and balance system (MSBS) suspends a model without physical support systems, thus enabling wind tunnel tests to be conducted without support interference. In this study, longitudinal dynamic characteristics of a delta-wing aircraft model at AOAs of up to 20° were investigated using an MSBS that could suspend an aircraft model continuously within an AOA range of ±40°. The acquired data were fitted to the dynamic derivative model using multiple regression analysis, considering the AOA acceleration. Additionally, the flowfield over the wing was also acquired by conducting particle image velocimetry (PIV) tests. For AOAs of ±5.9°, the dynamic aerodynamic forces agreed well with the dynamic derivative model. However, at higher AOAs, the dynamic derivative model was not sufficient for describing the aerodynamic forces. From the PIV tests, it was observed that the position of the vortex core during the pitch motion moved around the positions observed in the static cases.