The scientific concepts applied in aerospace engineering are present in their most fundamental form during secondary school education. Based on that, the grade 12 university physics curriculum (SPH4U1) proves to be extremely relevant when exploring a pathway in aerospace engineering.
Dynamics
![Picture](/uploads/9/6/7/9/96795674/four-forces-of-flight.gif?367)
Dynamics refers to the motion of bodies under the action of forces. In order to achieve flight many forces must be taken into consideration. The four main external forces acting on an aircraft are the thrust force, drag force, lift force, weight (gravitational) force.
In order to lift off the ground, the nose of the plane must be angled upwards. By doing so, a component of the drag force is expressed in the y-component. Resultantly, in order to lift off the ground, a plane must overcome both the drag force and gravitational force by increasing the thrust force and lift force. This is known to be true based on Newton's Second Law stating that an object will accelerate in the direction of the net force. Similarly, the same basic knowledge can be utilized when attempting to bring an airplane safely in for landing. These following forces are manipulated by the following through aerospace engineering design:
Drag Force- Raising and lowering of flaps on the wings of an airplane and streamlined designs; this increases surface area and as a result, increases air friction, which opposes the forward motion of the aircraft.
Weight (Gravitational Force)- Manipulating the size and materials used to build the aircraft; the force of gravity is dependent on mass, so by decreasing the quantity of matter through simpler designs and lightweight materials a plane can decrease it's weight relative to Earth's gravitational field strength.
Lift Force- Shape of wing design; most airplanes have a very streamlined shape known as an aerofoil, which is specifically designed so that air particles have to travel faster above the wing than below. As a result, there is less pressure abover the aerofoil than below according to Bernouilli's Equation. We know that objects travel from higher pressure to lower pressure, therefore, this difference in air pressure from the aerofoil produces lift.
In order to lift off the ground, the nose of the plane must be angled upwards. By doing so, a component of the drag force is expressed in the y-component. Resultantly, in order to lift off the ground, a plane must overcome both the drag force and gravitational force by increasing the thrust force and lift force. This is known to be true based on Newton's Second Law stating that an object will accelerate in the direction of the net force. Similarly, the same basic knowledge can be utilized when attempting to bring an airplane safely in for landing. These following forces are manipulated by the following through aerospace engineering design:
Drag Force- Raising and lowering of flaps on the wings of an airplane and streamlined designs; this increases surface area and as a result, increases air friction, which opposes the forward motion of the aircraft.
Weight (Gravitational Force)- Manipulating the size and materials used to build the aircraft; the force of gravity is dependent on mass, so by decreasing the quantity of matter through simpler designs and lightweight materials a plane can decrease it's weight relative to Earth's gravitational field strength.
Lift Force- Shape of wing design; most airplanes have a very streamlined shape known as an aerofoil, which is specifically designed so that air particles have to travel faster above the wing than below. As a result, there is less pressure abover the aerofoil than below according to Bernouilli's Equation. We know that objects travel from higher pressure to lower pressure, therefore, this difference in air pressure from the aerofoil produces lift.
Thrust Force: Propulsion (Manipulating propeller arrangement, size, and number) and combustion of gas.
Energy and Momentum
In SPH4U1, scientific concepts cover explosions and conservation of momentum. These principles are used by aerospace engineers in rocket propulsion to quantitatively determine its final kinetic energy after the explosion. However, the mass of the rocket continues to decrease as the amount of fuel combustion increases, therefore, further mathematics (calculus) not included in this course curriculum must be used to determine a correct value for kinetic energy. Overall, the expansion of the gas particles due to an increase in thermal energy caused by combustion, increases the thrust force acting on the aircraft.
Fields
In unit 3 of SPH4U1, we learn about gravitational fields, more specifically concepts regarding universal gravitation orbits. An aerospace engineer uses these concepts on a daily basis, especially if they pertain to the astronomical branch, where they are constantly designing aircrafts and satellites with Earth's gravitational field strength in mind. An example of this, is determining if an object will escape Earth's orbit. There are three main ways to predict this using the most fundamental form of calculations, where only kinetic and gravitational potential energy is being considered.
Case 1- Total Energy < 0
Initial Kinetic Energy < Initial Gravitational Potential Energy
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Case 2- Total Energy = 0
Initial Kinetic Energy = Initial Gravitational Potential Energy
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Case 3- Total Energy > 0
Initial Kinetic Energy > Initial Gravitational Potenetial Energy
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Note:
Height reference is at infinity, therefore, gravitational potential energy is negative.
Total Energy = Kinetic Energy + Gravitational Potential Energy
Height reference is at infinity, therefore, gravitational potential energy is negative.
Total Energy = Kinetic Energy + Gravitational Potential Energy