Computational Study of the Lift to Drag Ratio of Lifting Body Aircraft with Volumetrically Equivalent Fuselages of Different Profiles

Abstract

In this thesis, the effect of airfoiled fuselages on the improvement of overall lift to drag ratio of Unmanned Aerial Vehicle (UAV) is investigated, where along with the wing, fuselage also provides some lift. To compare the lift to drag ratio, two different types of fuselages are considered, one is conventional circular and another is airfoil cross-section. A three dimensional finite volume model is developed for numerical investigation of volumetrically equivalent fuselages. Spalart-Allamaras model is chosen as turbulence model. Hexahedral volume meshing is used with suitable boundary conditions. Developed finite volume model is validated with the available experimental data and farther investigation is carried out for different wing angle and angles of attack. Although at lower angle of attack lift coefficients for airfoiled fuselages are substantially higher as well as high drag coefficients which results lower lift to drag ratio but at higher angle of attack remarkable improvement of lift to drag ratio is noticeable. From the results, the optimum angle of attack at different speeds during takeoff, cruise and landing of the low speed UAVs are also found.