DEGREE PROJECT IN VEHICLE ENGINEERING, SECOND CYCLE, 30 CREDITS STOCKHOLM, SWEDEN 2017 Degree Project in Aeronautics Conceptual design, flying and handling qualities of a supersonic transport aircraft. NIKOLAOS PERGAMALIS KTH ROYAL INSTITUTE OF TECHNOLOGY SCHOOL OF ENGINEERING SCIENCES www.kth.se Abstract The purpose of this project is the design of a supersonic aircraft that is able to meet the market’s requirements, be economically viable and mitigate the current barriers. The initial requirements of the design have been set according to the understanding obtained from a brief market research, taking into account the market needs, in addition to the economical and environmental restrictions. The conceptual design proposed is a supersonic transport able to execute transatlantic flights carrying 15 passengers. The aerodynamics, propulsion data and weight of the design have been estimated using empirical relations and experimental data found in references. The design has been evaluated regarding its performance, stability, flying and handling qualities. The relevant models have been created using the software Matlab, while the flight testing has been executed at the Merlin MP521 engineering flight simulator. Finally, a discussion is made about the environmental impact of the supersonic transport, focusing on the aerodynamic noise, generated by the sonic boom, and the air pollutants emissions. Contents 1 Introduction 11 2 Conceptual Design 12 2.1 Market Research . 12 2.2 Initial Sizing . 14 2.2.1 Desired Requirements . 14 2.2.2 Initial takeoff weight estimation . 14 2.2.3 Mission profile and segments weight fractions . 15 2.2.4 Thrust-to-weight ratio . 17 2.2.5 Wing loading . 18 2.2.6 Constraint analysis . 19 2.2.7 Initial sizing results . 20 2.2.8 Wing . 21 2.2.9 Tail . 23 2.2.10 Fuselage . 24 2.2.11 Landing gear . 27 2.2.12 Propulsion . 29 2.2.13 Aircraft model . 35 2.2.14 Control surfaces . 37 3 Aerodynamics 38 3.1 Airfoils . 38 3.1.1 Airfoil selection . 38 3.1.2 Subsonic aerodynamic coefficients . 39 3.1.3 Supersonic aerodynamic coefficients . 40 3.2 Subsonic Lift-Curve Slope . 41 3.2.1 Wing - Fuselage Assembly . 41 3.2.2 Horizontal Tail . 42 3.2.3 Total aircraft . 43 3.3 Supersonic Lift-Curve Slope . 44 3.4 Maximum Lift Coefficient . 45 3.4.1 Clean configuration . 45 3.4.2 High lift devices . 48 3.4.3 Horizontal tail . 49 3.5 Subsonic Parasite Drag Coefficient . 50 3.5.1 Equivalent skin-friction method . 50 2 3.5.2 Component buildup method . 50 3.6 Supersonic Parasite Drag Coefficient . 52 3.7 Critical Mach number . 56 3.8 Drag due to Lift . 58 3.9 Miscellaneous Drag . 58 3.9.1 Flaps . 58 3.9.2 Spoilers . 59 3.9.3 Landing gear . 60 4 Weights 61 4.1 Weights Estimation Refined Method . 61 4.2 Center of Gravity . 62 5 Stability and Control 64 5.1 Subsonic Static Longitudinal Stability . 64 5.1.1 Aircraft Pitching Moments . 64 5.1.2 Subsonic Neutral Point . 65 5.1.3 Longitudinal Control and Trim Analysis . 66 5.2 Supersonic Static Longitudinal Stability . 69 5.2.1 Supersonic Neutral Point . 69 5.2.2 Trim Analysis . 69 5.3 Longitudinal Center of Gravity Location . 70 5.4 Directional Stability . 71 6 Performance 73 6.1 Climb Performance . 73 6.1.1 Minimum Time to Climb . 74 6.1.2 Minimum Fuel to Climb . 76 6.2 Range . 76 6.3 Descent and Loiter . 77 6.4 Takeoff . 78 6.5 Landing . 79 6.6 Total Mission . 81 7 Test Flight 82 7.1 Simulation . 82 7.2 Flying and Handling Qualities . 83 7.2.1 Modes excitation . 83 7.2.2 Dynamic Stability Requirements . 85 7.2.3 Longitudinal Dynamic Stability . 87 7.2.4 Lateral-Directional Dynamic Stability . 90 8 Environmental Impact 95 8.1 Sonic Boom . 95 8.2 Air Pollution . 99 8.2.1 Air Pollutants Identification . 99 8.2.2 Environmental Concerns of Supersonic Flight . 101 3 9 Discussion - Conclusions 107 4 List of Figures 2.1 Mission profile division. 16 2.2 Fuselage top view. 25 2.3 Fuselage side view. 25 2.4 Fuselage-wing assembly top view. 26 2.5 Fuselage-wing side view. 27 2.6 Airbus A320 main landing gear retraction and stowage. 27 2.7 Main landing gear logintudinal location [17]. 28 2.8 Diagram of nose landing gear location estimation. 29 2.9 Supersonic air inlets. 30 2.10 Three-shock external inlet. 31 2.11 Oblique shock wave. 32 2.12 Concorde rectangular ramp intakes. 33 2.13 EJ200 turbofan engine. 35 2.14 Aircraft model top view. 35 2.15 Aircraft model side view. 36 2.16 Aircraft model front view. 36 2.17 Rudder illustration. 37 3.1 NACA 64-006 lift curve for Re = 9·106 (XFOIL). 39 3.2 NACA 64-009 lift curve for Re = 9·106 (XFOIL). 40 3.3 Wing supersonic CNα for taper ratio of 0.2 [13]. 44 3.4 High aspect wing and airfoil maximum lift coefficient ratio at 0.2 Mach. 46 3.5 Stall angle of attack increment at subsonic Mach numbers of 0.2 - 0.6. 47 3.6 Trailing and leading edge high lift devices. 48 3.7 Wing TE flaps (red), LE flaps (magenta) and ailerons (cyan). 49 3.8 Sear-Haacks body volume distribution [9]. 54 3.9 Wing-body area rule design [9]. 54 3.10 Aircraft cross-section area distribution. 55 3.11 Wing critical Mach number in two-dimensional flow. 57 3.12 Wing control surfaces (blue) and spoilers (red). 59 5.1 Wing-body and tail mean aerodynamic centers [28]. 65 5.2 CG position influence on Cm at 0.5 Mach. 66 5 5.3 Variation of δt to trim with the flight speed and the static margin at SL flight. 67 5.4 Variation of δt to trim with the flight speed and the flight altitude for the subsonic Mach number range. 68 5.5 Variation of αtrim with the flight speed and the flight altitude for the subsonic Mach number range. 68 5.6 Variation of δt to trim with the flight speed and the flight altitude for the supersonic Mach number range and static margin of 0.1. 69 5.7 Variation of δt to trim with the flight speed and the flight altitude for the supersonic Mach number range and static margin of 0.35. 70 5.8 Variation of αtrim with the flight speed and the flight altitude for the supersonic Mach number range. 70 6.1 SEP contours diagram (dry thrust). 74 6.2 Flight path for minimum time to climb at cruise conditions. 75 6.3 Flight path for minimum fuel to climb at cruise conditions. 76 6.4 Illustration of takeoff path and distance. 78 6.5 Illustration of landing path and distance [13]. 80 7.1 Short-period mode frequency requirements [39]. 86 7.2 Elevator impulse input flight recording of the short period mode for 0.6 Mach at 30 kft. 88 7.3 Body axis pitch rate flight recording of the short period mode for 0.6 Mach at 30 kft. 88 7.4 Elevator step input flight recording of the phugoid mode for 0.6 Mach at 30 kft. 89 7.5 True airspeed flight recording of the phugoid mode for 0.6 Mach at 30 kft. 90 7.6 Euler roll angle flight recording of the spiral mode for 0.6 Mach at 30 kft. 90 7.7 Aileron input flight recording of the roll subsidence mode for 0.6 Mach at 30 kft. 91 7.8 Euler roll angle flight recording of the roll subsidence mode for 0.6 Mach at 30 kft. 92 7.9 Body axis roll rate flight recording of the roll subsidence mode for 0.6 Mach at 30 kft. 92 7.10 Rudder input flight recording of the dutch roll mode for 0.6 Mach at 30 kft. 93 7.11 Body axis roll rate flight recording of the dutch roll mode for 0.6 Mach at 30 kft. ..