B1 AVN: Introduction to Aviation PDF

B1 AVN: INTRODUCTION TO AVIATION Lesson 3: Aerodynamics: Understanding How Airplanes Fly Prepared by: Angela Marie S. Alfonso A.Y. 2024 - 2025 1  Aerodynamics is the way objects move through air. The rules of aerodynamics explain how an airplane is ab...

B1 AVN: INTRODUCTION TO AVIATION Lesson 3: Aerodynamics: Understanding How Airplanes Fly Prepared by: Angela Marie S. Alfonso A.Y. 2024 - 2025 1  Aerodynamics is the way objects move through air. The rules of aerodynamics explain how an airplane is able to fly. Anything that moves through air is affected by aerodynamics, from a rocket blasting off, to a kite flying. Since they are surrounded by air, even cars are affected by aerodynamics. 2 How Does An Aircraft Fly? 4 Forces of Flight Bernoulli’s Principle Newton’s Laws of Motion 3  FOUR FORCES OF FLIGHT In 1799, George Cayley introduced the idea of the modern fixed-wing aircraft and, in doing so, recognized the four basic forces involved in flight: lift, thrust, drag, and weight. 4 FOUR FORCES OF FLIGHT  FOUR FORCES OF FLIGHT Lift - the upward force that opposes weight, generated primarily by the wings as air flows over and under them. Weight - the downward force caused by gravity acting on the aircraft's mass. Thrust - the forward force produced by the engines, propelling the aircraft through the air. Drag - The resistance force that opposes thrust, caused by air friction as the aircraft moves. 5 FOUR FORCES OF FLIGHT  A drag is the aerodynamic force that opposes an aircraft's motion through the air. It acts in the opposite direction to the aircraft's velocity, meaning that it slows the aircraft down or requires additional thrust to maintain speed. There are several types of drag, which can generally be divided into two broad categories: parasite drag and induced drag. 6 PARASITE DRAG A parasite drag is the resistance created by the movement of the aircraft through the air. It increases with the square of airspeed, meaning that it becomes more significant as the aircraft flies faster. Parasite drag can be further broken down into three subtypes: ❖ Form Drag ❖ Skin Friction Drag ❖ Interference Drag 7 DRAG FORM DRAG This is the drag caused by the shape of an object moving through the air. The more blunt or non-aerodynamic an object, the higher the form drag. For example, a large, flat surface facing the airflow will generate more drag than a streamlined shape. 8 PARASITE DRAG SKIN FRICTION DRAG This occurs due to the friction between the aircraft's surface and the air particles that flow over it. Even a smooth surface has microscopic imperfections that can create friction. Polishing the surface of an aircraft can help reduce skin friction drag. 9 PARASITE DRAG INTERFERENCE DRAG A interference drag arises from the interaction of airflow between different parts of the aircraft, such as where the wings meet the fuselage or where the landing gear is attached. The merging of these airflow streams can create turbulence and increase drag. 10 PARASITE DRAG INDUCED DRAG An induced drag is a byproduct of lift, caused by high-pressure air from below the wing spilling over to the low-pressure area above, forming wingtip vortices. These vortices disrupt airflow and create drag. Induced drag is most significant at low speeds and decreases as airspeed increases but cannot be fully eliminated because it is linked to lift generation. 11 DRAG  Newton’s Laws of Motion are three physical laws that describe the relationship between the motion of an object and the forces acting on it. Formulated by Sir Isaac Newton in the 17th century, these laws provide a framework for understanding how objects behave, whether at rest or in motion. They are essential in fields ranging from engineering to astrophysics. 12 NEWTON’S LAWS OF MOTION ISAAC NEWTON An influential English mathematician, physicist, and astronomer Isaac Newton famous for developing the laws of motion and the theory of universal gravitation. His revolutionary work, Philosophiæ Naturalis Principia Mathematica (1687), introduced the three Laws of Motion, which are fundamental to classical mechanics. 13 NEWTON’S LAWS OF MOTION NEWTON’S 1ST LAW OF MOTION The Law of Inertia is an object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force. 14 NEWTON’S LAWS OF MOTION NEWTON’S 1ST LAW OF MOTION In relation to aircraft, it will not change its state of motion (takeoff, cruising, or landing) without the application of forces like thrust, drag, lift, or weight. For instance, during takeoff, thrust must overcome inertia to propel the aircraft forward. 15 NEWTON’S LAWS OF MOTION NEWTON’S 2nd LAW OF MOTION The Law of Acceleration is the acceleration of an object depends on the mass of the object and the amount of force applied. 16 NEWTON’S LAWS OF MOTION NEWTON’S 2nd LAW OF MOTION This law explains how an aircraft accelerates. For example, the more thrust produced by the engines (force), the greater the acceleration, provided the aircraft's mass remains constant. This is crucial during takeoff and maneuvers. 17 NEWTON’S LAWS OF MOTION NEWTON’S 3rd LAW OF MOTION The Law of Action and Reaction is whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. 18 NEWTON’S LAWS OF MOTION NEWTON’S 3rd LAW OF MOTION This principle is fundamental to flight; as engines push air backward (action), the aircraft is propelled forward (reaction). Similarly, wings generate lift by pushing air downward, resulting in an upward force that allows the aircraft to fly. 19 NEWTON’S LAWS OF MOTION NEWTON’S LAW OF MOTION Newton's laws of motion provide the foundational principles governing aircraft behavior, influencing design, performance, and safety in aviation. Understanding these laws is essential for pilots and engineers alike, as they directly relate to how aircraft achieve flight and maneuver in the sky. 20 NEWTON’S LAWS OF MOTION BERNOULLI’S PRINCIPLE An airfoil is a structure designed to obtain reaction upon its surface from the air through which it moves or that moves past such a structure. The airfoils are designed to produce lift, and this is a cross- sectional area of the wing. 21 DANIEL BERNOULLI An 18th century Swiss mathematician and physicist, Daniel Bernoulli is best known for his contributions to fluid dynamics, particularly the development of Bernoulli's Principle. This principle states that as the velocity of a fluid increases, its pressure decreases, which is crucial for understanding lift in aviation. 22 BERNOULLI’S PRINCIPLE Bernoulli's Principle states that in a flowing fluid, an increase in the fluid's speed occurs simultaneously with a decrease in pressure or potential energy. In simpler terms, where the speed of a fluid is higher, the pressure is lower. 23 BERNOULLI’S PRINCIPLE BERNOULLI’S PRINCIPLE This principle is crucial in explaining how lift is generated in aircraft wings (airfoils). As air moves faster over the curved top surface of the wing, the pressure above the wing decreases compared to the higher pressure below, creating lift. 24 BERNOULLI’S PRINCIPLE BERNOULLI’S PRINCIPLE Bernoulli’s equation mathematically describes the relationship between pressure, velocity, and height in a flowing fluid 25 BERNOULLI’S PRINCIPLE  Primary flight controls are essential systems in an aircraft that allow a pilot to manage and control the airplane’s attitude and direction during flight. These controls affect the movement of the aircraft around its three axes: longitudinal, lateral, and vertical. 26 THREE PRIMARY FLIGHT CONTROLS ❖ AILERONS ❖ ELEVATORS ❖ RUDDER 27 PRIMARY FLIGHT CONTROLS AILERONS Located on the trailing edge of each wing, control the aircraft's roll by moving in opposite directions, causing one wing to rise and the other to lower, which results in the aircraft rolling left or right. 28 PRIMARY FLIGHT CONTROLS ELEVATORS Found on the trailing edge of the horizontal stabilizer at the tail, manage the pitch, or the up-and-down movement of the aircraft's nose. When the elevator is raised, the nose of the aircraft climbs; when lowered, the nose descends. 29 PRIMARY FLIGHT CONTROLS RUDDER Attached to the vertical stabilizer, controls the yaw, which is the side-to-side movement of the aircraft's nose. By moving the rudder left or right, the pilot can steer the aircraft without rolling or pitching. 30 PRIMARY FLIGHT CONTROLS  AXES OF FLIGHT To control this movement, the pilot manipulates the flight controls to cause the aircraft to rotate about one or more of its three axes of rotation. These three axes, referred to as longitudinal, lateral and vertical, are each perpendicular to the others and intersect at the aircraft center of gravity. 31 THREE PRIMARY AXES ❖ LONGITUDINAL AXIS (ROLL) ❖ LATERAL AXIS (PITCH) ❖ VERTICAL AXIS (YAW) 32 AXES OF FLIGHT LONGITUDINAL AXIS (ROLL) An imaginary line through an aircraft from nose to tail, passing through its center of gravity. The longitudinal axis is also called the roll axis of the aircraft. Movement of the ailerons rotates an airplane about its longitudinal axis. 33 AXES OF FLIGHT LONGITUDINAL AXIS (ROLL) 34 AXES OF FLIGHT LATERAL AXIS (PITCH) The pitch axis also called transverse or lateral axis, passes through an aircraft from wingtip to wingtip. Rotation about this axis is called pitch and manages pitch through the elevators. Pitch changes the vertical direction that the aircraft's nose is pointing (a positive pitching motion raises the nose of the aircraft and lowers the tail). 35 AXES OF FLIGHT LATERAL AXIS (PITCH) 36 AXES OF FLIGHT VERTICAL AXIS (YAW) The yaw axis has its origin at the center of gravity and is directed towards the bottom of the aircraft, perpendicular to the wings and to the fuselage reference line. Motion about this axis is called yaw and governs yaw with the rudder. A positive yawing motion moves the nose of the aircraft to the right. 37 AXES OF FLIGHT VERTICAL AXIS (YAW) 38 AXES OF FLIGHT  The Angle of Attack (AOA) is the angle at which relative wind meets an airfoil. It is the angle formed by the chord of the airfoil and the direction of the relative wind or the vector representing the relative motion between the aircraft and the atmosphere. 39