Vacuum Braking System (MECH)

ABSTRACT:

A moving train contains energy, known as kinetic energy, which needs to be removed from the train in order to cause it to stop.  The simplest way of doing this is to convert the energy into heat.  

The conversion is usually done by applying a contact material to the rotating wheels or to discs attached to the axles.  The material creates friction and converts the kinetic energy into heat.  The wheels slow down and eventually the train stops.  The material used for braking is normally in the form of a block or pad

The vast majority of the world's trains are equipped with braking systems which use compressed air as the force used to push blocks on to wheels or pads on to discs.  These systems are known as "air brakes" or "pneumatic brakes".  The compressed air is transmitted along the train through a "brake pipe".  Changing the level of air pressure in the pipe causes a change in the state of the brake on each vehicle.  It can apply the brake, release it or hold it "on" after a partial application.  The system is in widespread use throughout the world.  An alternative to the air brake, known as the vacuum brake, was introduced around the early 1870s, the same time as the air brake.  

Like the air brake, the vacuum brake system is controlled through a brake pipe connecting a brake valve in the driver's cab with braking equipment on every vehicle.  The operation of the brake equipment on each vehicle depends on the condition of a vacuum created in the pipe by an ejector or exhauster.  The ejector, using steam on a steam locomotive, or an exhauster, using electric power on other types of train, removes atmospheric pressure from the brake pipe to create the vacuum.   With a full vacuum, the brake is released.  With no vacuum, i.e. normal atmospheric pressure in the brake pipe, the brake is fully applied.

Space Elevator (MECH)

ABSTRACT:

Experts agree that the biggest drain of energy takes place when a vehicle blasts off, pushing through Earth’s gravitational pull requires great amounts of fuel, but once they get out of our atmosphere, the rest is easy.

If you could cut out that “blast off” portion, space travel would be easier and much more fuel-efficient.

In a Space Elevator scenario, a Maglev vehicle would zoom up the side of an exceedingly tall structure and end up at a transfer point where they’d then board a craft to the Moon, Mars, or any other distant destination.

If it all sounds like too much science fiction, take a look at the requirements for making the Space Elevator a reality. A new material has been developed, however, called carbon nanotubes, that is 100 times as strong as steel but with only a fraction of the weight.

A carbon nanotube is an idea that makes this all sound much more achievable.          

In this concept, which is very fuel efficient and which brings space tourism closer common man uses the newly added concept of nanotubes to light.

Continuously Variable Transmission ( MECH )

ABSTRACT:

The stop go traffic condition has become synonymous with driving in our big cities.  In such a case will automatics transmission make sense to the Indian customer. Well the Indians haven’t taken to automatics like fish to water.  The reason being conventional automatics always consume slightly more fuel than manual transmission and the lack of sophisticated automatics.

With the increase in traffic conjunction in the cities stop go traffic has become a big hassle with constant gear changing.  In such a situation CVTs or continuous variable transmission proves it usefulness.  It is advantageous to use CVT over manual transmission as the engine will always operate at the optimum regime and throttle position.  Thereby it could maximize the power output relative to fuel position.

The continuously variable transmission will be commercialized within the next few years.  This trial blazing technology has the potential to revolutionize the automotive industry.  The superior performance attained by this technology ahs been hitherto unimaginable.  The reduction in exhaust emission and fuel consumption make this technology truly amazing and promising.

PULSE DETONATION ENGINE ( MECH )

ABSTRACT

A pulse detonation engine is an unsteady propulsive device in which the combustion chamber is periodically filled with a reactive gas mixture, a detonation is initiated, the detonation propagates through the chamber, and the product gases are exhausted. The high pressures and resultant momentum flux out of the chamber generate thrust.

                                     Quasi-steady thrust levels can be achieved by repeating this cycle at relatively high frequency and/or using more than one combustion chamber operating out of phase. A pulse detonation engine has a detonation chamber with a sidewall. At least two fuel ports are located in the sidewall, spaced longitudinally apart from each other. An oxygen fuel mixture is introduced into the forward port and detonated. This creates a detonation wave which propagates with an air fuel mixture introduced into the rearward fuel port.

                                 After the detonation, purge air passes through the chamber before the next detonation. A rotating sleeve valve mounted around the detonation opens and closes the fuel ports as well the purge ports. One of the newest and most exciting areas of pulse-jet development is the Pulse Detonation Engine (PDE). While they work on similar principles to a regular pulsejet, the PDE has one very fundamental difference -- it detonates the air/fuel mixture rather than just allowing it to simply deflagrate (burn vigorously). The exact details on many of the PDE designs currently being developed are rather sketchy -- mainly because they have the potential to be extremely valuable so most of companies researching in this field are not about to tell us what they're doing. It seems that nobody yet has the PDE developed to the point of being a practical propulsion device (or at least if they have, they're not telling anyone). From what I've been able to gather, the main focus is currently being placed on researching and improving the detonation process.

                                     The current generation of PDEs doesn’t seem capable of continuous running for any length of time -- they're more or less just single-shot devices requiring several seconds to recharge between detonations. Many developers have high hopes that the PDE will ultimately become the most cost-effective method of propelling supersonic sub-orbital craft. The ultra-high compressions obtained by detonation offer the potential for much better fuel-efficiency than even the best turbojet, and the fact that they are an air-breathing engine reduces the fuel-load and increases safety when compared to rocket motors.

SPACE SHUTTLES AND ITS ADVANCEMENTS ( MECH )

ABSTRACT

In its 23 year history, the NASA space shuttle program has seen exhilarating highs and devastating lows. The fleet has taken astronauts on dozens of successful missions, resulting in immeasurable scientific gains.  But this success has had a serious cost. In 1986, the challenger exploded during launch procedures, and on February 1^st of 2003, the Columbia broke up during re-entry over Texas.

This seminar report would be covering the following points:-

• A BRIEF HISTORY OF THE SPACE SHUTTLE.
• THE SPACE SHUTTLE MISSION.
• SPACE PLANES AND THE REPLACEMENT OF SPACE SHUTTLES.

This seminar will be taking a brief look  into the latest space planes namely the “HYPER SONIC PLANES WITH AIR BREATHING ENGINES” that are being planned to be rolled out by NASA for space exploration purpose.

RE-ENTRY OF SPACE VEHICLE ( MECH )

ABSTRACT

Re-entry capsules promises to intensify international competition in launch services, microgravity research and space technology development. These systems will also confer an important strategic advantage in the conduct of materials and in life science research.

The objective of this paper is to provide a modest degree of understanding of the complex inter-relation which exist between performance requirements mission constraints , vehicle design and trajectory selection of typical re-entry mission. A brief presentation of the flight regimes, the structural loading and heating environment experienced by booth no lifting and lifting re-entry vehicle is given.