WHY PETROL ENGINES ARE MORE POWERFUL THAN DIESEL ENGINES FOR THE SAME CUBIC CAPACITY?

Due to greater compression ratios and higher burning temperatures the diesel engine has a thermodynamic cycle that is basically more efficient than that of the gasoline engine. Then it uses less fuel per unit of power produced, but in order to do this it needs more space inside the cylinders to make the best use of the more extreme pressure and gas expansion characteristic.

Consequently, when the two engines being compared have the same volumetric capacities, than the amount of power of the gasoline engine is more, but it takes more fuel and a greater heat loss to achieve this.

World's Fastest Cars (2013)

World's Fastest Cars(2013)

While most of us can only dream of owning the fastest car in the world, some will do whatever it takes to possess one.

Here are 10 of the fastest street legal cars available in the market (production models, as opposed to concept or modified cars) these are tested, measured and verified top speeds (theoretical speeds do not count).

1. Bugatti Veyron Super Sport: 268 mph (431 km/h), 0-60 in 2.4 secs. Aluminum, Narrow Angle 8 Liter W16 Engine with 1200 hp, base price is $2,400,000. Although the Bugatti Veyron lost the title to SSC Ultimate Aero on March 2007, Bugatti challenged the record in Germany on July 10, 2010 with the new Super Sport and the Bugatti Veyron reclaimed the title of the fastest car in the world at 268 mph. The original Bugatti Veyron had a top speed of 253 mph, priced at $1,700,000 with 1001 hp.

2. Hennessey Venom GT: 266 mph (428 km/h), 0-60 mph in 2.5 seconds, has a 7.0 liter LS7 Turbocharged V8 Twin Turbo V8 Engine producing 1244 hp, with a price tag of $1,000,000 and up. The Venom GT was tested in April of 2013 in California when it hit 265.7 mph. It still has the potential to hit a top speed of 275 mph. This might just be the Veyron Super Sport's closest challenger!

3. Koenigsegg Agera R: 260 mph (418 km/h), 0-60 mph in 2.9 secs. 5.0-liter V8 Engine with twin turbo’s, housing 1099 hp. Base price is $1,600,000. If you're into snow sports, the Agera R can be fitted with a Ski Box as well as winter tires. While the Agera R has a massive theoretical top speed, the current tested top speed is 260 mph. Expect this snow car to be the Bugatti's arch enemy for the next 5 years.

There is a tie for #4.

4. SSC Ultimate Aero: 257 mph (413 km/h), 0-60 in 2.7 secs. Twin-Turbo V8 Engine with 1183 hp, base price is $654,400. Tested in March 2007 by Guinness World Records, The SSC Ultimate Aero was the fastest car in the world from March 2007 to July 2010. Shelby SuperCars will continue their quest to reclaim the fastest car title, and their new SSC Tuatura might do the job (we'll just have to wait).

4. 9ff GT9-R: 257 mph (413 km/h), 0-60 in 2.9 secs. The 4.0 Liter flat-6 Twin-Turbo Engine with 1120 hp, comes with a base price of $695,000. Based on the Porsche 911, the 9ff GT9-R 1120 hp version is limited to 20 units and the exterior may be modified to suit the owner.

4. Saleen S7 Twin-Turbo: 248 mph (399 km/h), 0-60 in 2.8 secs. Twin Turbo All Aluminum V8 Engine with 750 hp, base price is $555,000. Smooth and bad-ass. It will make you want to show it off non-stop.

5. Koenigsegg CCX: 245 mph (394 km/h), 0-60 in 3.2 secs. 90 Degree V8 Engine 806 hp, base price is $545,568. Made in Sweden, it is the older brother of the Agera R, only losing to 4 other supercars in the world.

6. McLaren F1: 240 mph (386 km/h), 0-60 in 3.2 secs. BMW S70/2 60 Degree V12 Engine with 627 hp, base price is $970,000. The fastest car in the 20th century with doors that looks like bat wings. Maybe Batman needs to order one and paint it black

7. Zenvo ST1: 233 mph (374 km/h), 0-60 in 2.9 secs. Twin-Charged 7.0 liter V8 Engine forging 1,104 hp. Base price: $1,225,000. The first Supercar from Zenvo Automotive, a Danish sports car company in pursuit of speed and perfection. This 100% Danish made supercar is limited to 15 units and the company even promised "flying doctors" to keep your baby functioning.

8. Pagani Huayra: 230 mph (370 km/h), 0-60 in 3.0 secs. Twin TurboCharged 6.0 liter V12 Engine from Mercedes AMG. It pumps out 720 horsepower to go with its 738 lb ft of torque. It comes with a seven speed auto-manual transmission. Pagani gives the name after the legendary Incan god of wind, Huayra-tata. The starting price is at £849,000, or $1,273,500.

Two at 9th place at 225 mph.

9. Gumpert Apollo: 225 mph (362 km/h), 0-60 in 3.0 secs, 4.2 liter V8 Engine that houses 650 hp. Base price: $450,000. Gumpert claims that the Apollo was designed such that it could drive upside-down in a tunnel with speeds at 190 mph or above. Of course, no one has tested this yet.

9. Noble M600: 225 mph (362 km/h), 0-60 in 3.7 secs. Twin-turbocharged 4.4-liter V8 Engine with 650 hp. Base price is $330,000. The Noble M600 also happens to be a very cool car. Its inconspicuous design sports a slender and contoured body which does not scream out for attention at every second of the day.

3-way tie for #10!

10. Aston Martin One-77: 220 mph (354 km/h), 0-60 in 3.4 secs. 7.3 litre V12 Engine with 750 hp. Base price: $1,850,000. The production of this is limited to 77, hence the name One-77. This is beauty and power packed into One.

10. Ascari A10: 220 mph (354 km/h), 0-60 in 2.8 secs. 5.0 litre BMW V8 S62 Engine with 625 hp. Base price: $650,000. The company planned to produce 50 of these supercars at its factory in Banbury, England.

10. Lamborghini Aventador: 220 mph (354 km/h), 0-60 in 2.9 secs. V12 Engine with 700 hp, base price is $379,700. According to Lamborghini, Aventador is the name of a Bull that entered into battle at the Saragossa Arena on October 1993. This is the fastest bull in the world!

Carbon Fibre Composite

Carbon Fibre Composite:

     

The Composite’s properties are mainly influenced by the choice of fibers. Three types of fibres are Glass fibre, Carbon fibre, Aramid fibre. All fibres have generally higher stress capacity than ordinary steel and are linear elastic until failure. The most important properties that differ between the fibre types are stiffness and tensile strain.

Carbon Fibre Properties:

• High Modulus of Elasticity 200 – 800 GPa.
• Tensile Strength 2500 – 6000 MPa.
• Density 1750 – 1950 Kg / m3.
• Ultimate Elongation 0.3 – 2.5 %.
• Carbon fibres do not absorb water.
• Carbon fibres are resistant to many chemical solutions.
• Carbon fibres withstand fatigue excellently.
• Carbon fibres do not show any creep or relaxation.
• Carbon fibre is electrically conductive.

Composites:

When the fibre and the matrix are combined into a new material it becomes a composite. The fibres may be placed in one direction in the composites and then the composite is unidirectional. However fibres may also be woven or bonded in many directions and the composite becomes bi or multi directional.

Composite Manufacturing:

• Hand lay up method
• Pultrusion method
• Filament winding
• Moulding

    CFRP is sometimes referred to as Carbon Fibre Reinforced Plastic is similar to fibre glass. Carbon fibre is woven into a textile material and resin such as epoxy resin is applied and allowed to cure. The resulting material that is very strong as it has the best strength to weight ratio of all construction materials. It is an improvement on glass fibre reinforced plastic, although much more expensive.

Carbon Composite (CFRP) Friction Bearings:

Friction bearings commonly use lubricating oil to separate the moving component from the mated non-moving bearing surface. Friction bearing surfaces commonly consist of a material that is softer than the supported component.

These friction bearings provide excellent dry running characteristics and can be used in operation after lubrication system failure making them an ideal solution for use in pumps and construction machinery as well as in mechanical engineering and shipbuilding or in offshore and onshore facilities to reduce maintenance and increase reliability. It can withstand up to 260 degree Celsius.

Some Interview Questions

1. Why are Head Gaskets blown?

Normally head gasket blows, when the engine overheats and they can also blow from incorrect installation or poor design. Head gaskets expand and contract according to engine temperature, these cycles may happen after a long period of time, causes the gasket to fail. If you’re replacing the gasket, check the engine block, and head for warping. Follow proper cleaning and torque specifications during assembly.

2. What is the difference between a Fence and a Wall?

A fence is either more temporary or constructed from materials, other than concrete, stone or brick.

3. What is the Difference between a Humidifier and Vaporizer?

The basic difference between humidifiers and vaporizers is that humidifiers disperse cool mist into the air, and vaporizers heat the water to disperse hot steam. Humidifiers are normally used in cooler climates, when due to the usage of heater, the air in the house becomes too dry for comfort and also, it becomes very difficult to breathe. Humidifiers release cool moisture droplets into the air.

Vaporizers also help in moistening the dry air in the house, but vaporizers release hot vapour into the air. There is a heating element in the vaporizers, which help in releasing steam. Vaporizers heat the water and then release vapours.

The basic difference between them is that one emits cold vapours, while the other one emits hot vapours.

4. What is the Difference between a Generator and Inverter?

An inverter is only effective if there is already a source of electrical energy. It cannot generate its own. It can simply convert electrical energy that is already there. On the other hand, a traditional generator cannot make AC current into DC current.

5. What is the Difference between Quantitative and Qualitative Research?

Quantitative research involves gathering data that is absolute, such as numerical data, so that it can be examined in as unbiased a manner as possible.

Qualitative research may yield stories, or pictures, or descriptions of feelings and emotions. The interpretations given by research subjects are given weight in qualitative research, so there is no seeking to limit their bias. At the same time, researchers tend to become more emotionally attached to qualitative research, and so their own bias may also play heavily into the results.

6. Difference between Absorption and Adsorption?

 In absorption, one substance (matter or energy) is taken into another substance. But in adsorption only the surface level interactions are taking place.

7. Difference between Liquid and Aqueous?

• Liquid is a state of matter, while aqueous is a special type of liquid formed by dissolving a compound in water

• All aqueous solutions are liquids, but not all liquids are aqueous solutions

8. Difference between Gas and Vapour?

· Vapour can turn back and forth into liquid and solid states but a gas cannot

· Gases cannot be see while vapours are visible

· Vapours settle down on ground while gases do not

9. Difference between Boiling Point and Melting Point

- The melting point is a defined for solids when it transfers from solid state to liquid state.

- The boiling point is defined for liquids for a state change from liquid to gas.

- Boiling point is highly dependent on the external pressure whereas the melting point is independent of the external pressure.

10. Why is sound faster in warm air?

The speed of sound in air c_air = 331.3 + (0.66 x T) m/s, where T is the temperature in °C.

The speed of sound is proportional to gas temperature and inversely proportional to its molar mass.

Sound is transferred by collisions of molecules. Therefore sound waves will travel faster on warm air because collisions of molecules of air in warm air is greater.

A Foam lighter than Air- Aerogel

Aerogel is a very special type of foam which is 99.8% air. Aerogel is a low-density solid-state material derived from gel in which the liquid component of the gel has been replaced with gas. The result is an extremely low density solid with several remarkable properties, most notably its effectiveness as a thermal insulator. Aerogels are solid, but can be less dense then air. 

It was first invented in the 1930s by Samuel Stephens Kistler, but was very brittle and could not be shaped. Aerogels are traditionally expensive and difficult to manufacture, and they are difficult to handle. Now a team of scientists have discovered how to make it flexible so that it does not break so easily. This means there are a lot of ways in which it can be used to solve problems.

It is nicknamed frozen smoke, solid smoke or blue smoke due to its translucent nature and the way light scatters in the material; however, it feels like exploded polystyrene (Styrofoam) to the touch.

Aerogels posses the lowest density and highest internal surface area of any known solid material, which makes them extremely high performance material for collision, damping, acoustic and thermal insulation, structural support and surface chemistry.

Properties:

1. Extremely low density
2. Very good thermal insulator
3. High specific surface area
4. Lowest dielectric constant

Metal aerogel Properties:

1. High specific surface area (100-500m2/g)
2. Electrically conductive!
3. Enhanced catalytic activity
4. Surprisingly capable thermal insulator

Interesting Facts:

1. A paperclip has a mass of approximately one gram. A one gram sample of aerogel has an internal surface area of between 250 and 3000m2 per gram (when produced in a weightless environment).
2. Lowest solid density: The lightest man-made material is an Aerogel with a density of only three times the density of air. However industrial aerogels can be made denser, up to 0.6 g/cc or more.

1. Highest porosity: Perhaps the only material that can have over 95% porosity, and a very wide pore size distribution, ranging from Angstroms (10-10 meter) to microns (10-6 meter).
2. Very high surface area: For some Aerogels, one ounce can have a surface area equal to a football field (over 3000 square meters per one gram).
3. Versatile compositions: Aerogels can be made with a wide range of chemical compositions.
4. Functional properties by design: Combinations of the above features can lead to Aerogel materials with useful properties such as:
   • Adsorbents,
   • Catalysts,
   • Insulators,
   • Semiconductors,
   • Piezoelectric,
   • Dielectric,
   • Ferroelectric,
   • Diffusion controllers,
   • Electric conductors,
   • Electric insulators.
5. Can hold (theoretically) 500 to 4,000 times its weight in applied force.

Computer Aided Three-dimensional Interactive Application(CATIA)

CATIA stands for Computer Aided Three-dimensional Interactive Application and is one of the most widely known and used software systems in the CAD world that is marketed and technically supported by IBM. 

The software is very intricate and is used by some of the biggest names in the business world. Currently over 20,000 companies use it worldwide and the distinguished list of names that use the software are top names such as Goodyear, Ford, Toyota, Hyundai, Boeing, Porsche, and Lear Jet just to name a few. All these top companies and more take advantage of the powerful applications that the software has to offer in order to help develop and design their products.

If you are planning on getting into such careers as design, manufacturing, or architecture then learning CATIA software will most likely be required of you at some point in time.

10 Best Universities/Colleges for Mechanical Engineering

Mechanical engineering is the mother of all engineering disciplines. 

 Mass, motion, force, energy, design, and manufacturing – these comprises the world of mechanical engineering. It encompasses the research, design, development, construction and testing of tools, machines and other mechanical equipment. Education from a proper well recognized university, college or school of engineering is vital for all the mechanical engineers due to the highly technical nature of mechanical engineering. 

 According to the ranking of mechanical engineering universities, the top 10 best universities or colleges for mechanical engineering are MIT, Stanford university, UC Berkeley, University of Cambridge, California Institute of Technology (Caltech), Imperial College London, University of Tokyo, ETH Zurich (Swiss Federal Institute of Technology), University of Oxford and National University of Singapore (NUS).

1) MIT (Massachusetts Institute of Technology):

 MIT (Massachusetts Institute of Technology) is perhaps the most renowned and the top best Mechanical Engineering University in the world, and is well known for its cutting edge ideas and philosophies on engineering education. When we talk about mechanical engineering then MIT is the best institute for it. Their mechanical engineering department offers three different undergraduate programs, all with specific occupational trajectories in mind and eight different graduate programs, including doctorate of science. MechE attracts and features an extraordinarily rich diversity and quantity of talented individuals, including 400 undergraduates, 500 graduate students and about 75 faculty members.
Website: meche.mit.edu

2) Stanford University:

California’s Stanford University is another high ranked among top 10 best mechanical engineering university in the world. Mechanical engineering at Stanford University is best known all over the world for its entrepreneurially oriented engineering achievements. Department of mechanical engineering at Stanford university offers degrees at bachelor’s, master’s and doctorate levels. 

Website: me.stanford.edu

3) University of California, Berkeley (UCB) (UC Berkeley):

According to many reports and world rankings, UC Berkeley is another top mechanical engineering school in the world. UCB offers undergraduate as well as graduate programs in the field, with specializations and more focuses in ocean engineering, mechatronics, energy and environment, manufacturing, bioengineering, computation and MEMS and NANO.
Website: me.berkeley.edu

4) University of Cambridge:

University of Cambridge is one of the best mechanical engineering institutes in the world. The University of Cambridge is one of the oldest universities in the world and one of the largest in the United Kingdom. Its reputation for outstanding academic achievement is known world-wide and reflects the intellectual achievement of its students, as well as the world-class original research carried out by the staff of the University and the Colleges. They aim at providing young mechanical engineers with all the analytical, design and computing skills that underpin modern engineering practice, while encouraging the creativity and problem-solving skills that are so important to a good mechanical engineer.
Website: eng.cam.ac.uk

5) California Institute of Technology (Caltech):

California Institute of Technology (caltech) is well known best mechanical engineering university. Mechanical Engineering at Caltech has a century-long record of excellence. It brings together three simple elements: exceptionally talented individuals; an emphasis on fundamentals principles of thermal sciences, fluid and solid mechanics, and mechanical systems; and an atmosphere that inspires one to address the critical technological challenges of the day. their particular interests evolve with time, but their core mission of training the leaders of tomorrow and conducting fundamental research to address major technological roadblocks remains constant. Today, you will find students and faculty working on nano structured fuel cells, laboratory earthquakes, active ferroelectric materials and devices, neural prosthetics, debris flows, response of structures against accidental explosion, quantum mechanical origins of the strength of materials and genetic algorithms for design.
Website: me.caltech.edu

6) Imperial College London:

Another best college for mechanical engineering in the world is Imperial College London. It remains in the list of top ten mechanical engineering colleges of the world since many years. The Department of Mechanical Engineering at Imperial College London is one of the largest and most advanced departments in mechanical engineering in the UK and across the world. They were the top-rated Department of Mechanical Engineering in the recent Research Assessment Exercise 2008, held by the UK Government. The overall mission of the Department is to deliver world-class scholarship, education and research in Mechanical Engineering, with particular regard to their application in industry, healthcare and commerce. Imperial college offers mechanical degrees at undergraduate, graduate and doctorate levels.
Website: imperial.ac.uk/mechanicalengineering

7) University of Tokyo:

University of Tokyo has a long history of providing best mechanical engineering degrees hence producing highly outstanding and technical mechanical engineers in the world. University of Tokyo offers mechanical engineering degrees at undergraduate as well as graduate level.
Website: mech.t.u-tokyo.ac.jp/english

8) Zurich (Swiss Federal Institute of Technology):

Zurich (Swiss Federal Institute of Technology) has one of the best Department of Mechanical and Process Engineering. They offer best engineering degrees well recognized all over the world. The Department of Mechanical and Process Engineering educates students for excellence and leadership in science and industry through cutting edge research on an international platform to face the challenges of the Swiss and global society and economy by engineering innovation in its technology fields. Their vision is to Reach and maintain excellence and leadership in fulfilling its mission as recognized (e.g. among the top five departments worldwide) by students, industry, peers and the board of ETH Zurich.
Website: mavt.ethz.ch

9) University of Oxford:

Oxford is the oldest university in the English-speaking world and lays claim to nine centuries of continuous existence. As an internationally renowned centre for teaching and research, Oxford attracts students and scholars from across the globe, with almost a quarter of our students from overseas. More than 130 nationalities are represented among a student population of over 18,000. University of oxford produces world’s best mechanical engineers who are well appreciated and well recognized in all of the industries worldwide. So University of oxford is one of the best mechanical engineering university in the world.
Website: eng.ox.ac.uk

10) National University of Singapore (NUS):

Acknowledged as one of the finest universities in the world, National University of Singapore (NUS) is a comprehensive university offering a broad-based curriculum underscored by multi-disciplinary courses and cross-faculty enrichment. Department of mechanical engineering at National University of Singapore is known to be one of the best in the world. It remains in top ten best mechanical engineering colleges of the world since a long time. Besides undergraduate, a graduate and doctorate degree, NUS also offers mechanical engineering internships for mechanical engineers during summer vacations. These are research based internships for national as well as international students.
Website: me.nus.edu.sg