Explain the working principle of jet propulsion with a neat sketch.

Working principle of jet propulsion - Jet propulsion is based on Newton’s second law and third law’s of motion. - Means producing forward axial thrust by means of reaction of jet of gases which are discharged rearward with a high velocity (aircraft, missile & submarine) - As applied to vehicle operating in fluid, a momentum is imparted to a mass of fluid in a such a manner that the reaction of imparted momentum furnishes a propulsive force. The magnitude of this propulsive force is termed as thrust. - For efficient production of large power, fuel is burnt in an atmospheric of compressed air combustion chamber, the product of combustion expanding first in gas turbine which drive the air compressor and second in nozzle from which thrust is desired for turbojet engine.

Turbojet consist of 1) Diffuser 2) Compressor 3) Combustion chamber 4) Turbine 5) Jet-nozzle. Function – Diffuser is to convert the K.E. or air into state pressure rise, air is compressed in compressor air is entered into combustion chamber where fuel is supplied and combustion take places at const. It expanded in

urbine where drops or pressure & increased in velocity. After gases leaves the turbine, they further expanded in nozzle & its leaves with high velocity to produce forward thrust…