ESCOLA SUPERIROR D’ENGINYIERIES INDUSTRIALS, AEROESPACIALS I AUDIOVISUALS DE TERRASSA Study of a feasible solution for a specific mission with an unmanned air vehicle (UAV/RPAS) Attachments Grau en Vehicles Aeroespacials Author Xavier Vidal Pedrola Director Aitor Martin Sierra Date 10th of June 2017 Study of a feasible solution for a specific mission with an unmanned air vehicle (UAV/RPAS) Index 1. PROPULSION SYSTEM ............................................................................ - 9 - 1.1. ENGINES ......................................................................................................... - 9 - 1.1.1. UL260i .................................................................................................................... - 9 - 1.1.2. UL350iS .................................................................................................................. - 9 - 1.1.3. Rotax 912 A .......................................................................................................... - 10 - 1.2. ENGINE SELECTION ........................................................................................ - 10 - 2. AERODYNAMICS .................................................................................... - 13 - 2.1. CONFIGURATION OF THE AIRCRAFT ................................................................. - 13 - 2.2. REYNOLDS NUMBER ...................................................................................... - 14 - 2.3. WING ............................................................................................................ - 14 - 2.3.1. Airfoil ..................................................................................................................... - 14 - 2.3.2. Wing shape ........................................................................................................... - 16 - 2.3.3. Control surfaces .................................................................................................... - 19 - 2.3.4. High lift devices ..................................................................................................... - 20 - 2.4. TAIL .............................................................................................................. - 21 - 2.4.1. Horizontal stabilizer .............................................................................................. - 21 - 2.4.2. Vertical stabilizer................................................................................................... - 26 - 2.5. PERFORMANCE .............................................................................................. - 28 - 2.5.1. Breguet equations (cruise conditions) .................................................................. - 29 - 2.5.2. Takeoff .................................................................................................................. - 31 - 2.5.3. Landing ................................................................................................................. - 32 - 3. STRUCTURES ......................................................................................... - 33 - 3.1. WEIGHT CALCULATIONS ................................................................................. - 33 - 3.1.1. Takeoff weight ...................................................................................................... - 33 - 3.1.2. Payload weight ..................................................................................................... - 33 - 3.1.3. Fuel weight ........................................................................................................... - 33 - 3.1.4. Operational empty weight ..................................................................................... - 34 - 3.2. CENTRE OF GRAVITY ...................................................................................... - 34 - 3.2.1. X-axis .................................................................................................................... - 35 - 3.2.2. Y-axis .................................................................................................................... - 35 - 3.2.3. Z-axis .................................................................................................................... - 35 - 3.3. UAV INERTIAS ............................................................................................... - 36 - 3.4. MATERIALS ................................................................................................... - 37 - 3.4.1. Materials studied and properties .......................................................................... - 38 - - 2 - Study of a feasible solution for a specific mission with an unmanned air vehicle (UAV/RPAS) 3.4.2. OWA results .......................................................................................................... - 39 - 3.5. WING DESIGN ................................................................................................ - 40 - 3.5.1. Wing loads ............................................................................................................ - 40 - 3.5.2. Wing parts ............................................................................................................. - 43 - 3.5.3. Wing box sizing ..................................................................................................... - 44 - 3.5.4. Spars dimensioning .............................................................................................. - 52 - 3.5.5. Rib spacing ........................................................................................................... - 54 - 3.5.6. Computational simulation ..................................................................................... - 55 - 3.6. HORIZONTAL STABILIZER ................................................................................ - 57 - 3.6.1. Horizontal stabilizer loads ..................................................................................... - 57 - 3.6.2. Spars area ............................................................................................................ - 58 - 3.6.3. Spars dimensioning .............................................................................................. - 59 - 3.6.4. Computational simulation ..................................................................................... - 61 - 3.7. LANDING GEAR .............................................................................................. - 63 - 4. BIBLIOGRAPHY ...................................................................................... - 65 - - 3 - Study of a feasible solution for a specific mission with an unmanned air vehicle (UAV/RPAS) List of figures: Figure 1: UL35iS piston engine. ................................................................................ - 9 - Figure 2: Rotax 912 installation on an aircraft. ........................................................ - 10 - Figure 3: Tail configurations. ................................................................................... - 13 - Figure 4: Comparison rectangular wing (purple) vs taper ratio wing (green). .......... - 17 - Figure 5: Stall effect depending on wing shape. ...................................................... - 18 - Figure 6: High lift devices used on the leading edge. .............................................. - 20 - Figure 7: High lift devices used on the trailing edge of the wing. ............................. - 21 - Figure 8: Estimated horizontal stabilizer volume for each type of aircraft. ............... - 22 - Figure 9: Regions defined by the deep stall effect. .................................................. - 24 - Figure 10: Diagram used during the elevator calculations. ...................................... - 25 - Figure 11: Dorsal wing on a commercial aircraft. .................................................... - 28 - Figure 12: Tail stalls depending on the elements studied. ....................................... - 28 - Figure 13: Airplane body axis and stability axis. ...................................................... - 34 - Figure 14: Local lift distribution along the span. ...................................................... - 40 - Figure 15: Local lift distribution used on the analysis. ............................................. - 41 - Figure 16: Shear stress distribution along half of the span. ..................................... - 42 - Figure 17: Bending moment along half of the span. ................................................ - 43 - Figure 18: Structural wing elements of a commercial plane. ................................... - 44 - Figure 19: First approach to wing box structure. ..................................................... - 45 - Figure 20: Wing box analytical model. .................................................................... - 46 - Figure 21: Shear flow decomposition. ..................................................................... - 47 - Figure 22: Rear spar area along half of the span. ................................................... - 50 - Figure 23: Skin thickness along half of the span. .................................................... - 52 - Figure 24: “I” cross section. ..................................................................................... - 53 - Figure 25: Wing internal structure. .......................................................................... - 55 - Figure 26: Von Mises stress analysis. ....................................................................