Tham khảo tài liệu 'mobile robots book 2011 part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Flight Dynamics Modelling and Experimental Validation for Unmanned Aerial Vehicles 191 gyration in each axis. These methods are commonly used on radio controlled airplanes and missiles. During the experiment the periods of the plane swung on each axis were obtained as well as some relevant lengths of the setup that were required for calculating the radii of gyration. Using this information as inputs to the software program Plane Geometry Blaine 1996 the moment of inertia along axis was determined. Table 1 summarizes the results. Pitch Roll Yaw Period s L mm 1027 1027 460 R mm - - 920 Radius of Gyration m Mass Kg 5 5 5 Moment of inertia kgm2 Table 1 Pendulum experiment results Software Aerodynamics Coefficients Two software packages Datcom Galbraith 2004 and Tornado torna do were used to estimate the aerodynamic coefficients of the K100 based on the geometric properties that were measured. Both packages perform computational fluid dynamics CFD calculations in order to produce their coefficient values. The CFD calculations use simplified geometry based on basic measurements only so they do not give extremely realistic coefficient values. Wind Tunnel Testing was required to compare the software aerodynamic coefficients with results found experimentally. Using the experimental results it was possible to determine which of the software packages produces better results for a particular coefficient and how much it differs from the experimental results. From these results it can be determined whether or not the CFD software can be used in future if aerodynamic coefficients for another UAV are to be obtained. If the software and experimental results agree well coefficients can be accurately determined without use of a wind tunnel. Wind tunnel testing is time consuming and requires access to a wind tunnel facility so it should be avoided if possible. Wind Tunnel Testing The .