Design And Fluid-Structure Interaction Study of a Wing Structure for a Medium-Range UAV

Abstract

This report presents the design of wing structure of a medium-range fixed-wing unmanned aerial vehicle (UAV) to carry a payload of 25 kg, and the Fluid-Structure Interaction (FSI) study of the designed wing for design validity and aerodynamic performance enhancement. FSI simulation helps us to study the performance of aircrafts in an economic and faster way, without having to conduct experiments every time, so that we can easily rectify faults and optimize the design. In this project, we finalized the flight requirements for the UAV and studied the properties of UAVs having similar requirements. Then, using iterative estimation technique, we calculated gross takeoff weight of the aircraft to be 122 kilograms. We selected appropriate wing configurations and used empirical scaling laws to calculate wing dimensions. After comparing characteristics curves of different airfoils in airfoil tools, we selected Wortmann fx-76-mp-140 airfoil for the wing. Using SOLIDWORKS, we generated a 3D CAD model of the wing structure including main spar, aft spar and ribs. We validated the design using XFLR5 and FSI simulation. We obtained lift to drag ratio, deformation and stress on the wing by performing one-way FSI simulation in ANSYS, where we coupled pressure loads from Fluent to Static Structural module.