Ram jet propulsive engine

RAMJET is a type of jet engine in which the air drawn in for combustion is compressed solely by the forward motion of the aircraft.
A ramjet uses this high pressure in front of the engine to force air through the tube, where it is heated by combusting some of it with fuel.
It is then passed through a nozzle to accelerate it to supersonic speeds. This acceleration gives the ramjet forward thrust.

1. RAM JET PROPULSIVE ENGINE NAME: JAIMIN A. KEMKAR EN. NO.: 160123119014 SEM. & BATCH: 7 TH D1 SUBJECT: POWER PLANT ENGINEERING (217910) GUIDED BY.: PROF. NIRAV JOSHI

2. CONTENTS INTRODUCTION OF JET PROPULSION AND CLASSIFICATION OF PROPULSIVE ENGINE INTRODUCTION OF RAM JET ENGINE APPLICATION OF RAM JET ENGINES ADVANTAGES AND LIMITATIONS OF RAM JET ENGINES REFERANCES

3. INTRODUCTION OF JET PROPULSION AND CLASSIFICATION OF PROPULSIVE ENGINE A jet propulsive engine is a reaction engine that discharges a fast moving jet of fluid to generate thrust in the opposite direction of the jet to propel the aircraft.

4. INTRODUCTION OF RAM JET ENGINE Ramjet is simplest of all the air breathing engines and consists of supersonic and subsonic diffusers, a combustion chamber with fuel injector and a discharge nozzle. As per the name all the compression in the cycle is made to occur in the intake diffuser, producing a significant rise in static pressure. Fuel is burnt in this high pressure air and the mixture is then expanded to ambient static pressure through a nozzle system .

5. The ramjet engine produces power by increasing the momentum of the working fluid with help of induction of energy by combustion of fuel, so that the momentum of the exhaust jet exceeds that of the incoming air, on a continuous basis. This high pressure gas is expanded through a nozzle , converting a low subsonic flow in the combustion chamber -- to a supersonic jet. The mixture of air and burnt fuel is exhausted through a convergent-divergent (C-D) nozzle. Exit pressure ( Pe ) is same as or nearly same as the ambient pressure. Thus, the chocking pressure ( Pc) at the throat is higher than the ambient pressure (Pa). However at low supersonic flights the exhaust may be sonic through a convergent nozzle . At flight Mach 5 and above the unit becomes a Supersonic Combustion Ramjet (SCRAMJET) in which the combustion is done in supersonic flow

6. APPLICATION OF RAM JET ENGINES Aircraft using ramjets: There are lots of aircrafts are powered by ramjet engines some of them are listed below. X-43A - The fastest unmanned aircraft was the X-43A in which NASA installed a scramjet engine . SR-71 Nord 1500 Griffon Missiles powered by ramjet engines: Our own Brahmos missile is powerd by scramjet engines Recently DRDO tested ASTRA missile which is again powered by ramjet engine.

7. ADVANTAGES RAM JET ENGINES Ramjet is very simple in construction and does not have any moving part such as compressor and turbine It is very cheap and requires almost no maintenance Greater thrust per unit engine weight than any other propulsion engine at supersonic speed except rocket At very high speed and high altitudes the specific fuel consumption is less than turbojet engine It can be operated with any type of liquid fuels and even with solid nuclear fuels

8. LIMITATIONS OF RAM JET ENGINES At low and moderate speeds, the fuel consumption is very high It can not be started on its own. It has to be accelerated to a certain flight velocity by some launching plateform Due to high air speed the combustion chamber requires flame holder to stabilize the combustion.

9. REFERANCES TEXTBOOK: POWER PLANT ENGINEERING BY BOOKSINDIA NPTEL PDFs ( http:// nptel.ac.in/courses/101101002/downloads/Lect-37.pdf ) WIKIPEDIA ( https:// en.wikipedia.org/wiki/Ramjet#Aircraft_using_ramjets ) THANK YOU