Estimation of lift and drag characteristics of UTM elang-1 UAV

This paper presents the aerodynamic estimation of lift and drag carried out on a three-dimensional UTM Elang-1 UAV by Computational Fluid Dynamics (CFD) simulation and the analytical calculations at sea level condition. UTM Elang-1 is an unmanned aerial vehicle, UAV developed by Universiti Teknologi Malaysia with the mission of surveillance and aeronautical study. It has a maximum take off weight of 105 kg and has a wing span of 3.57 m with the airfoil section of NACA 2415. The aerodynamic characteristics of the UTM Elang-1 such as coefficients of pressures and aerodynamics lift and drag had been measured either using a commercial CFD code, FLUENT or analytical calculations at various angles of attack. In the analytical portion, the characteristics of lift and drag as a function of angle of attack were determined by using USAF Datcom method. For CFD simulation, the model is implemented in the three dimensional unstructured multi domain code using a high resolution implicit second order upwind scheme. Simultaneously, the aerodynamic lift and drag obtained from the CFD simulation and analytical calculations had been compared. The results proved they were agreeable especially at a low angle of attack.