Detailed Flight Performance Analysis of a Fixed Wing UAV

The purpose of this paper is to investigate a method in which 6DOF mathematical simulation technique is applied for calculation and analysis for the flight performance of fixed wing UAV in detail. The performance calculating process is automated in segmented forms of the flight to simulate the whole flight of the UAV applying the features of commercial software MATLAB. The flight simulation code is made in segmented form breaking the total flight of the UAV into segments of climb, cruise, loiter and descent of the UAV. Every segment starts with the initial conditions set by the final conditions of the previous one. The user can make a whole mission profile in advance by dictating the total number of segments, the length of each segment or the dictating factors of each segment and type of mission profile. This program can also be used to confirm the point performance which is calculated by conventional methods and show the true ranges and endurances of each segment. This method is also used for graphical representation of the actual mission with a detailed breakdown of each segment. Unlike point performance, the user can check the performance of the aircraft at any point during the flight and also fly it with different speeds and altitude within one mission and check the feasibility of the mission. The example of UAV in this paper is a fixed wing aircraft with the ROTAX 914UL turbofan engine. The airfoil of the wing is NACA4412, and the typical aero data is generated for this airfoil. The program includes the engine data, the propeller data, the aircraft mass data and the aero data in particular. The propeller data is a complex function of velocity of aircraft and power provided by the engine. The engine data depends on the propeller efficiency, height and velocity of the aircraft. The aero data also depends on the velocity of the aircraft, thus the whole program is a complex interdependent simulation and every parameter is carefully modeled so that singularity in the simulation does not occur. The simulation is designed not only for the particular UAV but also can be generalized for other UAVs as well by changing the aircraft data. The features of the simulation include the user friendly technique to find the performance of any aircraft by just changing the data. It helps in making unlimited segments of the flight of the UAV to check whether a mission is possible before going on the mission. It shows that the method in this paper is advantageous in flight performance analysis in detail for UAV.