Mechanical Engineering Projects

Gravity power generation Mechanism

admin — Sun, 06 Nov 2011 06:38:28 +0000

The energy sources for man are drying up. The era of fossil fuels is going to end very soon. Scientists are now working on to find new renewable sources of energy. Along with renewable energy sources like light and wind comes gravity.

Gravity is a phenomenon that existed from the very beginning of the universe but only discovered by Sir Isaac Newton not more than 400 years ago. Recently scientists started generating energy from gravity.

The basic concept of a gravity power generating mechanism is simple. When a body goes down from a higher altitude to a lower one its potential energy is converted into kinetic energy via linear motion. This motion is converted circular motion and is then converted to electricity using a dynamo.

One challenge in this mechanism is about getting continuous supply of energy. A body cannot go downward infinitely, but for continuous power generation this practically impossible scenario is necessary.

An interesting solution for this problem was invented by Mr. Rajesh Mulchandani and he has applied for patent. He uses gravity and buoyancy of water to generate a continuous up and down motion. The mechanism consists of a water filled tank with 50-60meters high with 2 balanced masses capable of moving using both buoyancy and gravity.

You can see the full mechanism here http://powerfromgravity.com/invention.aspx.

gravity power generation mechanism

As a final year mechanical engineering project this may be too expensive. But there may be more simple ideas to generate motion continuously. Another example of such a mechanism can be found here. http://www.freepatentsonline.com/20090115195.pdf

Wish you all the best.

Electrical Power Generation System Using Railway Track

admin — Fri, 04 Feb 2011 04:26:56 +0000

The system includes a power source, such as a power generation device or an external powersource. The power co-generation system includes first and second electrical capacitance portions that are electrically coupled to the power source and that are configured to carry positive and negative charges, respectively. The power co-generation system further includes a biasing device that is configured to separate the first and second capacitance portions with respect to one another. Thus, by varying the distance between the capacitance portions in response to a vehicle on the rail, the capacitance portions cooperate to act as a variable capacitor that facilitates the co-generation of power with respect to the system. That is to say, the mechanical energy of the biasing device is converted into electrical energy for the system.

In accordance with another exemplary aspect of the present technique, a method of co-generating power via a vehicle traveling on a rail is provided. The method includes the act of driving first and second capacitor plates with respect to oneanother in response to the vehicle that is traveling on the rail. The method also includes the act of charging the first and second capacitor plates via a power source, such as a power generation device or an external power source. The method further includes biasing the first and second plates apart from one another, thereby displacing the plates with respect to one another. This displacement changes the electrical capacitance between the first and second plates and, resultantly, increases the electric potential between the first and second plates. In turn, this displacement of the first and second plates facilitates the co-generation of electrical energy from the kinetic and potential energy of the vehicle on the rail.

Reference

http://www.patentstorm.us/patents/7148581/fulltext.html

http://www.seminarprojects.com/Thread-power-generation-using-railway-track

Seminar Topic on Four wheel steering system

CJ Samson — Tue, 24 Aug 2010 00:54:17 +0000

Four-wheel steering, 4WS, also called rear-wheel steering or all-wheel steering, provides a means to actively steer the rear wheels during turning maneuvers. It should not be confused with four-wheel drive in which all four wheels of a vehicle are powered. It improves handling and helps the vehicle make tighter turns. Production-built cars tend to understeer or, in few instances, oversteer. If a car could automatically compensate for an understeer /oversteer problem, the driver would enjoy nearly neutral steering under varying conditions. 4WS is a serious effort on the part of automotive design engineers to provide near-neutral steering. The front wheels do most of the steering. Rear wheel turning is generally limited to half during an opposite direction turn. When both the front and rear wheels steer toward the same direction, they are said to be in-phase and this produces a kind of sideways movement of the car at low speeds. When the front and rear wheels are steered in opposite direction, this is called anti-phase, counter-phase or opposite-phase and it produces a sharper, tighter turn.

ADVANTAGES OF 4WS

The vehicle’s cornering behavior becomes more stable and controllable at high speeds as well as on wet or slippery road surfaces.
The vehicle’s response to steering input becomes quicker and more precise throughout the vehicle’s entire speed range.
The vehicle’s straight-line stability at high speeds is improved. Negative effects of road irregularities and crosswinds on the vehicle’s stability are minimized.
Stability in lane changing at high speeds is improved. The vehicle is less likely to go into a spin even in situations in which the driver must make a sudden and relatively large change of direction.
By steering the rear wheels in the direction opposite the front wheels at low speeds, the vehicle’s turning circle is greatly reduced. Therefore, vehicle maneuvering on narrow roads and during parking becomes easier.

Catalytic converter for cars

CJ Samson — Mon, 23 Aug 2010 14:52:22 +0000

Millions of cars or the road means only one thing, an excellent source for air pollution. The amount of pollution that all cars produce together can create big problems. The amount of pollution that all cars produce together can cause big problems. Government created laws that restrict the amount of pollution that cars produce to solve it. Auto makers have made many improvements to car engines and fuel systems to keep up with these laws. In 1975, an interesting device called catalytic converter was created. The device, converts harmful pollutants into less harmful emissions before they ever leave the car’s exhaust system.

The exhaust from the combustion in a car engine is comprised of six main ingredients:

Nitrogen gas, Carbon dioxide and water vapor are the three of the main emissions. These gases do not cause damage to the atmosphere.
Carbon Monoxide, other hydrocarbons and Nitrogen Oxides result in a majority of the pollution caused by cars.

Carbon monoxide is a colorless and odorless gas that can kill you if too much is inhaled
Hydrocarbons are produced during incomplete combustion and these hydrocarbons can be broken down by the sun, creating ground level Ozone, also known as smog.
Nitrogen Oxides can cause acid rains.

Catalytic convertors are designed to reduce these last three emissions.

Construction:

The core is often a ceramic/stainless steel foil honeycomb.

- Increases the amount of surface area

- Support the catalyst. Also called “catalyst support”.

A wash coat is used to make converters more efficient because a mixture of silica and alumina will form a rough and irregular surface which leads to more surface area. Therefore, more places for active precious metal sites. The catalyst is added to the wash coat before applied to the core.

Platinum is the most active catalyst and is widely used. Other materials such as palladium and rhodium have also been used.

Hybrid vehicles

admin — Sat, 14 Aug 2010 18:15:09 +0000

The dictionary defines hybrid as something of mixed origin. A hybrid vehicle is one that combines a smaller than normal internal combustion gasoline engine with an electric motor. An engine that combines two or more sources of power is called a hybrid engine.

Typical features in a hybrid include the following:
• Produces much less power than an average
• Produces much less pollution than standard gasoline cars
• Usually constructed of ultra light weight materials like carbon fiber or aluminum to overcome the power gap.
• Generally designed to be more aerodynamic than most cars, allowing them to “slice” through the air instead of pushing it out of the way
• A process called regenerative braking is employed to store the kinetic energy generated by brake use in the batteries, which in turn will power the electric motor.
Power usage:
• Electric power is used at starts and stops, low speeds (generally below 25 km/hr)
• Gasoline engine comes to play at cruising or highway speeds

There are two types of gasoline-electric hybrids:
• Parallel hybrid:
Gasoline engine and electric motor work together to move the car forward
• Series hybrid
Gasoline engine either directly powers an electric motor that powers the vehicle, or changes batteries.

Hybrids achieve improved efficiencies using several approaches:
• Employ regenerative braking to recover energy and downsize or right size the engine or primary power source.
• Control the engine or primary power source to operate more efficiently and/or work more often in a more efficient range.

Air Cars

CJ Samson — Fri, 13 Aug 2010 18:10:45 +0000

We do it every day without thinking. Start the engine, drive around, fill up with fuel, pay a lot of money and pollute the atmosphere some more! But, it doesn’t have to be that way, many alternative sources of fuel are being developed.

Science fiction novelist Jules Verne had predicted that cars would one day run on air. Guess what the future of fuel is? You guessed it right, its air! Think about a car that runs on air. The air we breathe, the air that is for free. Imagine, it costs nothing to fill up your car with gas, and that gas also happens to be the same gas that fills our lungs with every breath!

The future of transportation will soon be whooshing down the road in the form of an unparalleled “green” earth- friendly technology that everyone will want to get their hands on as soon as they can: The Air Car. It is hard to believe that compressed air can be used to drive vehicles. However that is true and the “air car”, as it is popularly known, has caught the attention of researchers worldwide.

The topic air car can be made a project by making a demo model of the air car engine. The working of the engine can be better understood from the following videos.

How does the Air car work?

Actually all engines work with compressed air. Most engines suck it in, heat it up, it pressurizes and it pushes on a piston. In an air car we pressurize the air first, so when we apply it to the piston, the piston is pushed. The idea is as simple as that.

Working model of Hovercraft

CJ Samson — Thu, 05 Aug 2010 10:51:42 +0000

The idea of making a Hovercraft dates back to 1716 when Emmanual Swedenborg recorded a design, but it was short lived. In 1870, Sir John Thornycroft filled patents involving air lubricated hulls. And it was in 1959 a hovercraft was built, by Christopher Sydney Cockerell by discovering the Momentum Curtain theory. Hover craft also called Air cushion vehicle (ACV) travels on any kind of flat surface. It is supported by a cushion of pressurized air.

Design

Can be powered by one or more engines
Small crafts have a single engine with the drive split through a gear box
Usually one engine drives the fan responsible for lifting the vehicle
The other forces air from

Working

Two main principles:

1) Lift

2) Propulsion

A skirt is required to quarantine airflow
No contact with ground hence friction is eliminated
The shape of the body affects stability
All parts are essential for proper working

Parts

1) Lifting fan: Usually a centrifugal fan is preferred. When rotated air is sucked into the center hole, it is coupled via a gearbox and connected to the engine

2) Thrust propellers: An aircraft type propeller with variable type pitch blades. Diameter ranges from nine feet to nineteen feet. In bigger crafts the propellers are rotated while in smaller ones, rudders are used.

3) Skirt: Flexible strip which is fitted below the bottom edges of the plenum chamber. Skirt design is the most sensitive design parameter as it protects the craft and helps to lift it even higher.

In theory hover crafts are simple machines but a plethora of problems exist to make a functioning hovercraft. The plans as well as the design must be flawless. To build a hovercraft one must be well aware of the demands of construction. Only then can one design a hovercraft.

Electronic fuel injection (EFI)

CJ Samson — Fri, 30 Jul 2010 13:13:46 +0000

Electronic Fuel Injection (EFI) is a substitute for the conventional metering system which mixes the air and fuel in the correct ratio before feeding it down to the main cylinder to power the vehicle.

Usually in a bike a carburetor is responsible for carrying out this task. But, the downside of using a carburetor is that it has fixed settings and it has certain limitations. To overcome this negative aspect of a new system has been introduced. However, for this brand new system to work, it needs data from several sensors. These sensors include an engine speed sensor, temperature sensor, voltage sensor, throttle position sensor, oxygen sensor and an air flow sensor. The data collected from the various sensors are send to the Electronic control unit (ECU). The ECU makes use of the data provided from the sensors to determine the spark advance, the length of spark and other parameters. Then the exact air fuel mixture for that particular instant is fed into the cylinder which in turn delivers optimum power and clean exhaust. All this process is done continuously and happens many times in every second.

A cross section of a fuel injector is shown below:

Typical EFI components:

1) Injectors

2) Electronic control module (ECU)

3) Fuel pressure regulator

4) Fuel pump

5) Wiring harness

6) Sensors

Advantage:

1) Although the electronic fuel injection is much more complicated than a carburetor, it is much more efficient.

2) Fault finding is easy with the right tools

Disadvantage:

1) Higher cost than carburetor.

Hydrogen (water) Powered vehicle

CJ Samson — Thu, 29 Jul 2010 12:58:27 +0000

Not a Gimmick! Finally the science of Hydrogen automotive power has been made a reality! Technically a device that converts the energy stored in hydrogen into motion can be called a Hydrogen engine. Hydrogen would make a great fuel for the environment since burning Hydrogen produces nothing but water!

Hydrogen Powered vehicle essentially consists of the following

1) Fuel tank

Liquid hydrogen is stored in a tank at the rear of the car and is pumped forward to the fuel cell stack as and when required.

2) Fuel Cell Stack

When Hydrogen is combined with Oxygen in a fuel cell a chemical reaction creates electricity.

1) Battery Pack

The battery pack is periodically recharged by the fuel cell. The power from the battery pack is used to provide rapid acceleration.

2) Electric Motor

The stack provides electricity for the electric motor that powers the vehicle

Right from the year 1625, when Johann Baptista van Helmont discovered the gas, Hydrogen; people were curious enough to find the uses of the new found gas. It nearly took a mind boggling 181 years to develop an internal combustion engine which runs on a mixture of hydrogen and water by the icon of 18^th century who is none other than, Francois Issac de Rivaz. The Swiss inventor, is credited with the development and construction of the world’s first IC engine back in 1806. From then onwards, it was always a challenge to develop the best IC engine. This has lead to developing different varieties of engines.

A pictorial representation of the Hydrogen powered vehicle is shown below.

Remote controlled material handling equipment (RCMHE)

CJ Samson — Wed, 28 Jul 2010 12:55:53 +0000

Prior to the introduction of the so called “Material handling equipment” humans had to perform physical labor to carry out heavy duty tasks. This could be made possible by employing a huge number of workers. However, when the goods came in bulk unloading and loading turned out to be a very time consuming affair. The use of Material handling equipment in logistics has played a significant role in making the loading and unloading activities easier and faster.

Ask yourself the question “Why are ‘Remote controlled’ material handling equipment used?” and almost instantly you arrive at the logical answer that the chief benefit would be allowing personal to control their machine from a safe distance.

Remote control can be achieved by two different modes:

1) Radio frequency (RF) Signals

RF signals are further divided into two categories.

a) Narrow-band system b) Spread spectrum system.

2) Infrared light

Infrared method works by transmitting a beam of light

Infrared mode of radio control is preferred over RF signals because of the safety and precision that it offers. Since the infrared method works by transmitting a beam of light, once the beam is out of sight, the beam is obstructed and the controls turn off. That is, the operator must always be in view of the RCMHE, which in turns aids safety as the full visibility of the operator over the machine is critical. Precise, in the sense that with the use of RF technology there is always a chance of interference with other signals and might lead to accidents, Infrared remote control makes this type of mistake impossible.

Applications:

1) Transfer of components from one container to another especially fragile objects

2) Transfer of hazardous/explosive objects

3) Operation in high temperature environment

Although it is advantages to use RCMHE, proper training for the staff handling the RCMHE is a prerequisite to ensure safe working.