Posted tagged ‘engine’

AUTOMOBILE ENGINES

September 10, 2011

The working of an automobile engine follows the same principle as an internal combustion engine. Air, from outside, enters the engine through the air cleaner and reaches the throttle plate.
The pedal in your car is the control for the amount of air that you would want to be taken in, and you control it by pressing on this gas pedal.
The air is then distributed through the intake manifold of the cylinders.

At some point fuel is injected into the air stream, and the mixture vaporizes and is drawn into the cylinders as they start their intake stroke.

This way, when the cylinder has reached its bottom, it has drawn in sufficient mixture. As it moves up, compressing the mixture, the spark plug ignites the mixture, and as the powerful gas formed expands, it pushes the cylinder to the bottom with the cylinder once again drawing in the mixture.

In designing automobile engines, you need to be a specialist in automobile engineering.
The consideration that is taken while designing such an engine is whether it should be a carburetor or a diesel one. carburetor engines are most commonly found in passenger cars and low capacity trucks, while trucks with a capacity over two tons are fitted with diesel engines, including dump trucks, trailer tractors and bus.

Increasingly the medium and low-capacity vehicles are being fitted with diesel engines, since the fuel consumption of these engines are 30% to 50% lower than the carburetor engines.
Diesel engines not only cost more, but maintenance is much more expensive than the other type of engine. Diesels require more metal parts per kilowatt.
The critical parts of diesel engines are made of alloy steel, and the fuel injection system is much more expensive than carburetor engines.

However, the cost of manufacturing carburetor engines has increased with the use of higher mechanical grade components, considering the thermal loads of the material used. At the same time the use of high alloys and increase in production costs have contributed to the higher price of such engines.

There is a sharp rise in using aluminum alloys in design of carburetor engines in passenger cars, and with the use of high octane petrol, the cost of operation of these cars have come down extensively. Using alloy steel in constructing the engine body and other parts of the engine, makes the car lighter and hence fuel consumption goes down substantially.

The main parts that are made of high steel alloy are the main casting of the engine, the cylinder head, water and oil pumps, oil filter housing, end covers of the generator and starter, and the intake pipes. It has been observed that by using high steel alloys, the weight of the car is reduced by 35%.

The power per liter, per unit of piston area, and the brake effective pressure are 6% to 8% lower in air-cooled engines, compared to engines having liquid cooling mechanism. This is due to the fact that in engines with liquid cooling there are great losses in cylinder charging caused by the high temperature in pipes, ducts in the head, cylinder walls and head, etc.

The size of air cooled engines are much bigger than the engines with liquid cooling having the same capacity, and this is because the cylinder axes difference is larger in air-cooled engines. Taking account of the radiator dimensions, if both engines are compared, the air-cooled engine will vary slightly with its height a little longer than or approximately the same length as the water-cooled engine. As far as the width and the height is concerned both engines are about the same.

The auxiliary units of the feed and ignition, and generator and starter systems are a bit difficult to fit on the body of the air-cooled engines, because of the presence of hoods and having a danger of over-heating.

The Supernatural Case of Combined studies..!

August 23, 2011

My life is just another SI engine whose fly wheel is being malfunctioning for over 2 years….

The energy needed regulation ..
whether it is growth or decline its always been an exponential one…!
The thing i always hunt in search is for The Stability,Consistency…!
Indeed this friendship day brought some good news to smile….
When i look back i see a complete mess resulted due to my unplanned experiments, overcast , gloomy , Shadowy academics…!!
But when i look for the future i saw my bloody experiments taking their shape to furnish me extraordinary results!

SKYACTIV TECHNOLOGY

August 23, 2011

01-2012-Mazda3-Skyactiv-Image-PETROL ENGINE-AUTOMATIC TRANSMISSION

Highlights of the SKYACTIV technologies:

  • SKYACTIV-G: a next-generation highly-efficient direct-injection gasoline engine with the world’s highest compression ratio of 14.0:1
  • SKYACTIV-D: a next-generation clean diesel engine with the world’s lowest compression ratio of 14.0:1
  • SKYACTIV-Drive: a next-generation highly-efficient automatic transmission
  • A next-generation manual transmission with a light shift feel, compact size and significantly reduced weight
  • A next-generation lightweight, highly-rigid body with outstanding crash safety performance
  • A next-generation high-performance lightweight chassis that balances precise handling with a comfortable ride


– First product to be equipped with SKYACTIV technology will be a Mazda Demio featuring an improved, fuel-efficient, next-generation direct-injection engine that achieves fuel economy of 30 km/L.

01-inline-skyactiv-technologies-chASSIS DESIGN-BODY DESIGN-DRIVE DESIGN-DIRECT INJECTION GASOLINE ENGINE


Overview of the SKYACTIV technologies

1. SKYACTIV-G
A next-generation highly-efficient direct-injection gasoline engine that achieves the world’s highest gasoline engine compression ratio of 14.0:1 with no abnormal combustion (knocking)
  • The world’s first gasoline engine for mass production vehicles to achieve a high compression ratio of 14.0:1
  • Significantly improved engine efficiency thanks to the high compression combustion, resulting in 15 percent increases in fuel efficiency and torque
  • Improved everyday driving thanks to increased torque at low- to mid-engine speeds
  • A 4-2-1 exhaust system, cavity pistons, multi hole injectors and other innovations enable the high compression ratio
2. SKYACTIV-D
A next-generation clean diesel engine that will meet global emissions regulations without expensive NOx after treatments — urea selective catalytic reduction (SCR) or a Lean NOx Trap (LNT) — thanks to the world’s lowest diesel engine compression ratio of 14.0:1
  • 20 percent better fuel efficiency thanks to the low compression ratio of 14.0:1
  • A new two-stage turbocharger realizes smooth and linear response from low to high engine speeds, and greatly increases low- and high-end torque (up to the 5,200 rpm rev limit)
  • Complies with global emissions regulations (Euro6 in Europe, Tier2Bin5 in North America, and the Post New Long-Term Regulations in Japan), without expensive NOx after treatment
3. SKYACTIV-Drive
A next-generation highly efficient automatic transmission that achieves excellent torque transfer efficiency through a wider lock-up range and features the best attributes of all transmission types
  • Combines all the advantages of conventional automatic transmissions, continuously variable transmissions, and dual clutch transmissions
  • A dramatically widened lock-up range improves torque transfer efficiency and realizes a direct driving feel that is equivalent to a manual transmission
  • A 4-to-7 percent improvement in fuel economy compared to the current transmission
4. SKYACTIV-MT
A light and compact next-generation manual transmission with crisp and light shift feel like that of a sports car, optimized for a front-engine front-wheel-drive layout
  • Short stroke and light shift feel
  • Significantly reduced size and weight due to a revised structure
  • More efficient vehicle packaging thanks to its compact size
  • Improved fuel economy due to reduced internal friction
5. SKYACTIV-Body
A next-generation lightweight, highly-rigid body with outstanding crash safety performance and high rigidity for greater driving pleasure
  • High rigidity and lightness (8 percent lighter, 30 percent more rigid)
  • Outstanding crash safety performance and lightness
  • A “straight structure” in which each part of the frame is configured to be as straight as possible. Additionally, a “continuous framework” approach was adopted in which each section functions in a coordinated manner with the other connecting sections
  • Reduced weight through optimized bonding methods and expanded use of high-tensile steel
6. SKYACTIV-Chassis
A next-generation high-performance lightweight chassis that balances precise handling with a comfortable ride feel to realize driving pleasure
  • Newly developed front strut and rear multilink suspension ensures high rigidity and lightness (The entire chassis is 14 percent lighter than the previous version.)
  • Mid-speed agility and high-speed stability — enhanced ride quality at all speeds achieved through a revision of the functional allocation of all the suspension and steering components

ULTIMATE ECO CAR

August 23, 2011

01-ultimate_eco_car-developments of hybrid technology-development of hydrogen fuel-fuel cell-hybrid technology

Continuous improvement in conventional engines, including lean-burn gasoline engines, direct injection gasoline engines and common rail direct-injection diesel engines, as well as engines modified to use alternative fuels, such as compressed natural gas (CNG) or electricity (for Electric Vehicle).

Engineers may disagree about which fuel or car propulsion system is best, but they do agree that hybrid technology is the core for eco-car development.


01-ultimate_eco_car-diesel hybrid-fuel cell vehicle-alternate fuel hybrid vehicles


“Plug-in hybrid” technology brings further potential for substantial CO2 emissions reductions from vehicles. It has a higher battery capacity and is thus more fuel-efficient than the current hybrid, assisted by the power of engine. For a short-distance drive, it could be run with electricity charged during the night. Depending on how electricity is generated, the vehicle could run with much lower CO2 emissions. In order to commercialize the plug-in hybrid, there is again a need for a breakthrough in battery technology. It is necessary to develop a smaller-sized battery with higher capacity. Plug-in hybrids could contribute to reducing substantial amounts of CO2 emissions from vehicles, as well as fossil fuel use, by charging from cleaner electricity sources in the future.

Challenges of increasing power performance

In order to improve the driving performance, its power train was completely redesigned. To increase motor output, a high-voltage power-control was adopted. Although this technology was used in industrial machines and trains, the idea of incorporating it into an automobile did not easily occur at first. First of all, the system itself would take up a substantial amount of space and secondly, there was no prior example of applying this method to a motor that switches between output and power generation at such a dizzy pace.

Once the development of the high-voltage power circuit began, there was a mountain of problems, such as what to do about the heat generated by increasing voltage and the noise generated. To reevaluate the power train, the project team had to produce prototypes and repeat numerous tests. The prototyping stage went to seven prototypes instead of the usual three, and the total distance driven by these prototypes during testing exceeded one million kilometers.

ULTIMATE ECO CAR

August 23, 2011

01-ultimate_eco_car-developments of hybrid technology-development of hydrogen fuel-fuel cell-hybrid technology

Continuous improvement in conventional engines, including lean-burn gasoline engines, direct injection gasoline engines and common rail direct-injection diesel engines, as well as engines modified to use alternative fuels, such as compressed natural gas (CNG) or electricity (for Electric Vehicle).

Engineers may disagree about which fuel or car propulsion system is best, but they do agree that hybrid technology is the core for eco-car development.


01-ultimate_eco_car-diesel hybrid-fuel cell vehicle-alternate fuel hybrid vehicles


“Plug-in hybrid” technology brings further potential for substantial CO2 emissions reductions from vehicles. It has a higher battery capacity and is thus more fuel-efficient than the current hybrid, assisted by the power of engine. For a short-distance drive, it could be run with electricity charged during the night. Depending on how electricity is generated, the vehicle could run with much lower CO2 emissions. In order to commercialize the plug-in hybrid, there is again a need for a breakthrough in battery technology. It is necessary to develop a smaller-sized battery with higher capacity. Plug-in hybrids could contribute to reducing substantial amounts of CO2 emissions from vehicles, as well as fossil fuel use, by charging from cleaner electricity sources in the future.

Challenges of increasing power performance

In order to improve the driving performance, its power train was completely redesigned. To increase motor output, a high-voltage power-control was adopted. Although this technology was used in industrial machines and trains, the idea of incorporating it into an automobile did not easily occur at first. First of all, the system itself would take up a substantial amount of space and secondly, there was no prior example of applying this method to a motor that switches between output and power generation at such a dizzy pace.

Once the development of the high-voltage power circuit began, there was a mountain of problems, such as what to do about the heat generated by increasing voltage and the noise generated. To reevaluate the power train, the project team had to produce prototypes and repeat numerous tests. The prototyping stage went to seven prototypes instead of the usual three, and the total distance driven by these prototypes during testing exceeded one million kilometers.

MECHANICAL ENGG QUESTIONS

August 22, 2011

1. What is the importance of the Thermodynamics in the field of Mechanical Engineering?
All the mechanical engineering systems are studied with the help of thermodynamics. Hence it is very important for the mechanical engineers.

2. How many Laws of Thermodynamics are there?
There are three laws of the thermodynamics.

First Law: Energy can be neither created nor destroyed. It can only change forms.In any process in an isolated system, the total energy remains the same.


Second Law: When two isolated systems in separate but nearby regions of space, each in thermodynamic equilibrium in itself, but not in equilibrium with each other at first, are at some time allowed to interact, breaking the isolation that separates the two systems, and they exchange matter or energy, they will eventually reach a mutual thermodynamic equilibrium. The sum of the entropies of the initial, isolated systems is less than or equal to the entropy of the final exchanging systems. In the process of reaching a new thermodynamic equilibrium, entropy has increased, or at least has not decreased.

Third Law: As temperature approaches absolute zero, the entropy of a system approaches a minimum.

3. State Laws of conservation of energy?
According to the laws of conservation of energy, “energy can neither be created nor be destroyed. It can only be transformed from one form to another.”

4. Is the boiler a closed system?
Yes definitely the boiler is a closed system.

5. What is Carnot engine?
It was being designed by Carnot and let me tell you that Carnot engine is an imaginary engine which follows the Carnot cycle and provides 100% efficiency.

6. Which formula forms a link between the Thermodynamics and Electro chemistry?
Gibbs Helmholtz formula is the formula which forms the link between the thermodynamics and electromagnetism.

∆Hs/R = [∂ lnp /∂ (1/T)]x

where: x – mole fraction of CO2 in the liquid phase
p – CO2 partial pressure (kPa)
T – temperature (K)
R – universal gas constant
α – mole ratio in the liquid phase (mole CO2 per mole of amine)

7. Which is the hardest compound known?
Diamond.

8. What is Hess Law?
According to the Hess law the energy transfer is simply independent of the path being followed. If the reactant and the product of the whole process are the same then same amount of energy will be dissipated or absorbed.


9. Which has more efficiency: Diesel engine or Petrol engines?
Off course Diesel engine has the better efficiency out of two.