and mission of the Switchblade 300?58 Write features of the wing and fuselage of the Switchblade 300.
59 What are the cruise speed and ceiling of the Switchblade 300?
60 What are two payloads of the Switchblade 300?
61 Write the maximum speed, endurance, and ceiling of ScanEagle.
62 For ScanEagle, what are: (1) the maximum takeoff weight and (2) weight of payload?
63 What are sensors of Boeing‐Insitu ScanEagle?
64 According to FAR Parts 48 and 107, may you operate an sUAS at night in the US? Why?
65 What UAV is defined as a small unmanned aircraft by FAR?
66 Name four expendable UAVs and their manufacturers.
67 List missions of Insitu ScanEagle.
68 Describe the performance of the XQ‐58 Valkyrie.
69 What is the capacity of bombs in the XQ‐58 Valkyrie?
70 Write: (1) wingspan, (2) length, and (3) total payload weight of the Bayraktar TB2.
71 Write the maximum speed and endurance of the Bayraktar TB2.
72 What can a Bayraktar TB2 provide as its mission?
73 What is the payload of Bayraktar TB2?
Note
1 1 Model airplane – generally known collectively as the sport and pastime of aeromodelling – here is not an aircraft model for the wind tunnel application. It is a small remotely controlled (RC) plane that is often designed by non‐aeroengineer traditional airplane enthusiasts and is usually built in a garage.
Part II The Air Vehicle
This part introduces the subsystem at the heart of any UAS, the air vehicle. The section begins with a basic discussion of the aerodynamics (Chapter 3), followed by illustrations of how to analyze the key areas of air‐vehicle performance (Chapter 4) and flight stability and control (Chapter 5). The various means of propulsion (Chapter 6) commonly used by UAVs are explored, including an introduction to the subject of rotary wing (e.g., quadcopter) and ducted fan concepts. Finally, some structural and load (Chapter 7) topics of importance to UAV engineers are described.
3 Aerodynamics
3.1 Overview
Aerodynamics is the science that involves the study of the behavior (i.e., dynamics) of air when confronting a moving object (e.g., air vehicle). The UAV has a number of components that are characterized by their aerodynamic outputs (e.g., lift), two of which are wing and tail. A wing/tail is considered as a lifting surface in which the lift is produced due to the pressure difference between lower and upper surfaces. In contrast, surfaces such as aileron, rudder, and elevator are referred to as the control surfaces. Lifting surfaces are generally fixed while control surfaces are always moving up/down or left/right. Both lifting and control surfaces are functions of their aerodynamic features.
The primary forces that act on an air vehicle are thrust, lift, drag, and gravity (or weight). They are shown in Figure 3.1. The UAV components that have a direct contact with moving air contribute to aerodynamic features. A number of elements have considerable contributions on an air vehicle’s aerodynamic features. They are mainly: (1) wing, (2) tail, (3) fuselage, (4) engine cowling, (5) landing gear, and (6) payload. Three primary aerodynamic components of an air vehicle are: (1) wing, (2) tail, and (3) fuselage.
The primary aerodynamic function of the wing and tail is to generate sufficient lift force or simply lift (L). However, they have two other undesirable products, namely drag (D) and nose‐down pitching moment (M). The fuselage is not fundamentally considered as an aerodynamic component based on its function. However, fuselage has a considerable role in creating drag, while it generates a little lift.
In this chapter, aerodynamic forces (mainly lift and drag), airfoil, pressure distribution, friction drag, induced drag, drag polar, air vehicle drag, boundary layer, and aerodynamic efficiency will be briefly covered.
3.2 Aerodynamic Forces
The primary function of the UAV aerodynamic components (e.g., wing and tail) is to generate sufficient lift force or simply lift (L). However, they have two other aerodynamic products, namely drag force or drag (D) and nose‐down (Figure 3.2) pitching moment (M). While a UAV designer is looking to maximize the lift, the other two (drag and pitching moment) must be minimized. In this chapter, lift and drag are presented, while in Chapter 5, the pitching moment will be introduced.
Figure 3.1 Forces on an air vehicle during a level flight
Figure 3.2 Aerodynamic lift, drag, and pitching moment
The aerodynamic forces of lift and drag [8] are functions of the following factors: (1) aircraft configuration, aircraft/wing angle of attack (α), (3) aircraft geometry, (4) airspeed (V), (5) air density (ρ), (6) Reynolds number of the flow, and (7) air viscosity:
(3.1)
(3.2)
where ρ is air density, V is velocity, S is the wing planform area, and CL and CD are the lift and drag coefficients respectively. The calculations of lift and drag coefficients will be presented in the coming sections.
The lift force or simply lift is always defined as the component of the aerodynamic force perpendicular to the relative wind. The drag is always defined as the component of the aerodynamic force parallel to the relative wind (V∞). In other words, lift is always perpendicular and drag is always parallel to the relative wind. Figure
