AERONAUTICAL LECTURING NOTES

Write down all type of power plants that are being used in aircrafts? Reciprocating engines Gas turbine engine Ramjet engine Scramjet engine What are the types of gas turbine engines? Turbo jet Turbo prop Tubo fan Turbo shaft Which gas turbine engine is fuel efficient? Turbo fan What are the components of Turbojet engine? Inlet Compressor Combustion chamber Tubine Nozzle Exhaust  Write the advantages of gas turbine power plants. The capital cost of plant is low. This can be quickly commissioned. It requires less space. Capacity to use wide variety of fuels Write the disadvantages of gas turbine power plants About two third of the power developed by the turbine is used to drive the compressor. Hence net output of plant is low. Low efficiency Needs special cooling arrangements Operating temperature is high of the order of 20000C.

What is Newtons second law and how it matches with Aircraft Engine? If some mass ‘M” is accelerated, then a force presents. Same way the mass of fuel air mixture is accelerated by a chemical reaction thus creates exhaust force. What is Newtons third law and how it matches with Aircraft Engine? For every action there is an equal but opposite reaction.  The exhaust force created is also having equal and opposite reaction called Thrust which is always in the direction of flight. What is a propeller? And how it functions? A propeller is simply a rotating aerofoil. It provides thrust in the same way as how an aerofoil mounted on wing generates lift. To know how a wing generates lift click here . When propeller rotates, the hub has to cover a least circular path whereas the tip has to travel a large circular path; in the same time. So propeller tip will be experiencing high speed than hub; that means from hub to tip speed is increasing. Suppose if we want to hav...

What are the types of rockets? Based on the fuel (Propellant) type used Solid Propellant Liquid propellant Hybrid Electric rocket Ionic rocket What is missile? Missile is same like a rocket. The purpose of use is to destroy enemies. Missile will be launched in inclined position with reference to earth horizon. In what way does a rocket differ from aircraft? Rocket is operating in space where no air (No oxygen for  combustion ) is available and also in the air. So in order to have an efficient thrust from combustion it needs to have separate tank for oxygen storage. But aircraft since it is operating in air; it has air breathing engines. 

Define shear stress and shear strain. The two equal and opposite force act tangentially on any cross sectional plane of the body tending to slide one part of the body over the other part. The stress induced is called shear stress and the corresponding strain is known as shear strain. Define- Rigidity modulus The shear stress is directly proportional to shear strain. N = Shear stress/Shear strain Define Bulk-modulus The ratio of direct stress to volumetric strain is called as Bulk modulus. K    =   Direct stress/ Volumetric strain Define- lateral strain When a body is subjected to axial load P, The length of the body is increased. The axial deformation of the length of the body is called lateral strain. Define- longitudinal strain The strain right angle to the direction of the applied load is called lateral strain. Define Poisson’s ratio. When a body is stressed, within its elastic limit, the ratio of lateral strain...

Define stress. When an external force acts on a body, it undergoes deformation. At the same time the body resists deformation. The magnitude of the resisting force is numerically equal to the applied force. This internal resisting force per unit area is called stress. Stress = Force/Area     N/m 2 Define strain When a body is subjected to an external force, there is some change of dimension in the body. Numerically the strain is equal to the ratio of change in length to the original length of the body. Strain = Change in length/Original length e = δ L/L Define- elastic limit Some external force is acting on the body, the body tends to deformation. If the force is released from the body it regain to the original position. This is called elastic limit. State Hooke’s law It states that when a material is loaded, within its elastic limit, the stress is directly proportional to the strain. Stress α Strain σ α e Define – Young’s modulu...

What is helicopter? Rotary wing aircraft with engine or engines (heavier than air) which can sustain in flight (within atmosphere), because of the lift produced by its rotary wings. What is the major difference between Aircraft to rotor craft? Aircraft needs runway to take-off and land whereas a rotor craft can take off and land without runway. What is spacecraft? A Fixed wing heavier than air aircraft, with engine, which can fly in space because of thrust. What is rocket? Rocket is a flying object which is operating on atmosphere as well as in space because of thrust developed by its engines.

   What is engineering? Engineering is the combination of Science and mathematics to serve for human needs. It has many divisions. Some are aerospace, computer science, civil, Electrical, Mechanical etc. Who is an Engineer? Engineers understand what people needs and design them, construct it or machine it, maintain it. Also they will have a look on cost, quality and timing. Engineer creates an object which is not present with the help of science and mathematics. What is aeronautical engineering? Understanding the concept of flying within the atmosphere, developing/creating flying objects by engineering ideas. What is aerospace engineering? Understanding the concept of flying in space as well as in atmosphere, with that knowledge they may able to design a spacecraft, rocket or they may work in space.