Calculating Aerodynamic Coefficients of Fixed Wing Aircrafts Using DATCOM Software with Special Focus on Rudderless Flying-wing UAVs

In recent years, fixed-wing unmanned aerial vehicles (UAVs) have gained widespread attention in various civilian and military applications which require accurate control and guidance systems, enhanced maneuvering capabilities, and high stealth specifications. In order to design a robust control system to enable different tracking and path-following purposes, it is desired to establish a comprehensive and precise aerodynamic model. So, an accurate and straightforward approach is required for calculating the aerodynamic coefficients which are used to derive aerodynamic forces and moments. This research develops a procedure to calculate the required aerodynamic coefficients of fixed-wing aircrafts using Digital DATCOM software, which is used to establish an aerodynamic model, with a special study on rudderless flying-wing UAVs. The data input card is prepared with respect to the design and physical characteristics of the considered UAV model and related airfoil structure. By calling the input card of the given UAV model in DATCOM software, the static longitudinal/lateral stability, dynamic stability, and control coefficients and their derivatives are calculated. A ۳D model is also established. Finally, the output file is imported into MATLAB environment for further analysis and implementation in dynamic modeling for control system design.