The difference between a fighter and an airliner jet motor.

If you have ever wondered what is the difference between the jet engine of the airliner which took you from London to New York or Moscow and the one used in a fighter jet, in the next few lines we try to give you some answers.
We may first consider how a jet engine works:
A typical turbo jet is made of four main parts namely the compressor, the combustor, the turbine and the exhaust.
the compressor, sucks the air into the engine and as the name suggests compresses the air and thus increases the pressure. it then directs the compressed air into the combustion chamber.

                    the compressor is a series of propellers which can suck the air into the jet engine.

The combustion chamber is the place where the temperature of the air is increased and the fuel is sprayed to get mixed with it before the mixture is ignited to burn.

the hot section

The turbine is a propeller, turned by the expanded hot air, which directs the air out of the back of the engine through the exhaust, providing the thrust required by the aircraft and also rotating the .

 What is the difference?

The design explained above is rather over simplified but it does the job for the time being.

This basic design, can be used alongside with some improvements for it to suit different needs and situations.

The difference between a turbofan(the jet engine of an airliner) and a turbojet, is that in a turbofan this jet engine is contained in larger container and only a fraction of the incoming air goes trough the
 jet engine. It allows a greater mass of air to enter the engine. As we know, momentum is the product of mass and velocity. So for the same momentum, a turbofan requires a smaller velocity and so it is quieter.
In a fighter jet however, there is a process of reheating of the air coming out of the exhaust. The after burner is used to increase the thrust, in take-off and high climbs. So in effect, it provides the same momentum with a smaller mass and greater velocity and of curse there is no need to worry about the noise!!!!!

The Big Changes in aviation, The milestone: 2050

Good old days of Concorde are gone, and now we are all convinced that without making profit, even the greatest engineering masterpieces are nothing more than, well, great masterpieces.
 Ever Since the shuttle program was announced finished, people are waiting to see what is the next big thing. In fact any exciting project that we have had in this industry, has soon come to an end.
But if you think this is the end of the sky story, or if you think it will always stay the same, think again.
This picture are from Airbus website. What you will not see in them is a sign of repetitive ideas.

This project is called Eco-Climb. Imagine you sit on your seats, ready for the take-off, and then a machine launches you up towards the sky. Now I know that the whole idea sounds strange, or even impractical. but there are things that make it a very good idea. Like the runways will be shorter, the take-off is faster, and most importantly, "propelled acceleration will allow for steeper climb from airports to minimise noise and reach efficient cruise altitudes more quickly" says the Airbus website.
But it is not all. they are also working on other things that can be revolutionary. The ideas like gliding, safely of course. This is said to decrease the amount of emissions, as well as being less noisy.
These aside we all want to see what will the air-crafts look like.
Well there are many possibilities, but just to give you a taste of it, watch this video.

Morphing program, Shape-Shifting Air-Planes

Have ever seen an eagle flying? Well if you have not, you probably want to see these:

                                                    photos by Charles W. Melton

Now apart from the eagle looking good, there is something else to notice. Got it? No? Ok then have look at these:

What you should have noticed is the fact that eagle's wings are designed to change shape, where as our regular airplanes have wings which are pretty much the same at different parts of the flight (apart from the flaps and the ailerons etc .) So what is bad about it? the bad thing is that they are not efficient enough. In other words "Airplanes today are a design compromise. They have a fixed-wing structure that is not ideal for every part of a typical flight" says George Lesieutre, professor of aerospace engineering at Penn State.

To resolve this issue, engineers are working on wings that can change shape. In fact the concept is not even new. the idea is to make sure that the drag force is minimised throughout the flight. George Lesieutre says "Being able to change the shape of the wings to reduce drag and power, which vary with flight speed, could optimize fuel consumption so that commercial planes could fly more efficiently."

NASA has stated that there is more to this study. In fact they have been working on this for a few years. they call it the 'Morphing' program. The key thing that will allow them to make such air planes is that Morphing wings are not made of the conventional mechanically connected material, but instead they are made of nano-technological "smart" material, and even more, there will some sort of outer skin like scales of a fish. To give you an idea about the planes that we might use to travel from London to New York, lets look at this animation that can be found on YouTube:

So, shape-shifting is now more than just a concept. In fact, with other revolutionary ideas like X-48C being considered, there can be major changes to the way we think of air-planes today.

Next time we will see how close these engineering achievements are to the industry, and whether or not they will go the way that other revolutionary ideas like Concord went.