Tuesday 13 August 2019

DIFFERENCE BETWEEN COOLANT AND LUBRICANT EXPLAINED !!

We will be talking these two terms in context to engine.


COOLANT :

Coolant in engine is used to absorb the heat of the engine. It is used in radiator and circulated outside the engine(They pass through the engine through jackets provided).



Water is used as coolant but now a days chemicals are used along with water. They prevent the rusting, cool engine fast and doesn't freeze.

LUBRICANT:

Lubricants are used inside the engine. They are hydrocarbons made up of base oil and additives. Base oil is the product of refining of crude like diesel and petrol and additives are chemicals mixed with base oil for specific purposes.





They reduce friction, seals the engines, indicates service life, clean the carbon, cool the engines, preventing breaking of parts and distributes the pressure. Lubricants outside the engine are used as greases and gear oil.

Monday 12 August 2019

KNOW WHY AUTOMATIC TRANSMISSION VEHICLE GIVES LESS MILAGE THEN MANUAL TRANSMISSION VEHICLE !!


You might have wondered why 100cc scooter gives less mileage than 100cc manual transmission bike. Think about it where a 100cc scooter returns mileage near 40-50 Kmpl, an average 100cc motorcycle provides mileage over 60 Kmpl. The answer to this question lies in the transmission used where the scooters use automatic CVT transmission, while motorcycles use a proper 4 or 5 speed manual transmission.We will discuss about the reason behind this in this article.

Lets start with the purpose of a gearbox. The engine of a vehicle runs at a certain rotary speed or revolutions per minute ( RPM ). The required speed of revolution of the wheels is usually much less than that. For example, a typical 100cc bike engine can rev upto 6000rpm, but if the wheels ( 18 inch dia ) of a typical 100cc bike move at that speed, it would reach a velocity of 518 kmph!
So basically the gearbox is the intermediate mechanism which allows the engine and wheels to run at different rpm. 





The scootys use a system called a Continuously Variable Transmission ( CVT ), which in its simplest form is just a a cone pulley system with belts which allows for automatic adjustment of speed. The 100cc bike on the other hand has a manual gearbox, which requires you to manually select an ideal gear ratio for the given speed. Usually bikes have 5 gear speed ratios to choose from nowadays and they are thus called 5 speed gearboxes. 




Fuel economy depends on your RPM. The lower the rpm, the better fuel economy. Bikes with gears allow us to shift into higher gears and by doing so, the rpms decrease.At a given speed (say 40kmph), when in higher gear (4th gear), the bike has lesser rpms as compared to it going at same speed (40kmph) in a lower gear (3rd).In a gearless scooter, the rpms just keep building up continuously. So it has lesser fuel economy.
 



Also, another major contributor to this is the fact that gearless scooters have a centrifugal clutch. In such a system, as the speed is building up, the centrifugal force acting on the clutch increases. Thus, it always remains partially engaged (detached from the input shaft). This translates into power loss and thus lesser fuel economy.  

 
The clutch is not controlled by the rider, it works automatically, and the clutch is also a pretty inefficient unit which draws its power from none other than the engine. This results in more loss of power and to make that up in terms of performance, the efficiency of the scooter takes a hit.


But most consumers don't mind because of the convenience of not shifting gears manually seems a fair trade-off. However, automatic transmissions are getting more high tech as we speak, and very soon this difference in efficiency will be negligible. 

KNOW WHY NEW TEST VEHICLES ARE CAMOUFLAGED !!

We have all seen photos of anticipated upcoming models wrapped in black padding and crazy checkerboard and swirl patterns, and might have wondered if all that is really necessary.We will discuss the reason behind wrapping the new cars in this article.


While much of a new car or truck’s development happens behind closed doors, there’s no substitute for real-world testing on both private tracks and public roads, at which point a test vehicle – called a “mule” in automotive language.After manufacturing every vehicle has to be tested on road to see how it behaves.


To travel in public , automotive engineers for decades have employed visual deception which is known as camouflage to disguise what they are working on or testing from the eyes of always interested and ever-present media and competitive automakers.



Camouflage is important to automakers as they develop and test vehicles, for a variety of reasons. An accidental early look at a new design can impact the sales of existing vehicles as consumers compare their current purchase considerations to those on the horizon.

The camouflage is there to deceive your eyes. Most car companies use them to protect the design of their, soon to be released, cars. The camouflage hides any sleek edges and doesn't give a clear look into the car's details. No, it doesn't necessarily hide the car as a whole and they are usually easy to distinguish what type of car it is. But, it does hide their new design.




Lets compare, we'll use the 2016 Honda civic as an example. Look specifically at the hood. notice any fine details to the hood like raising or lowering sections? You can also see this "illusion" in the grill of the car, where the Honda logo would be located. and lastly look towards the sides of the doors, notice how the non-camouflaged one looks to cave-in more towards the bottom.


The last thing a manufacturer wants is for its upcoming model to create a market that it is not ready to fill. Worse yet, when the car is finally released, its design can feel stale because the internet and magazines have been publishing pictures of it for a year or two. 

Sunday 11 August 2019

COMMON DIFFERENCE EXPLAINED !!

DIFFERENCE BETWEEN RESUME AND CV:

A curriculum vitae (CV) provides a summary of your experience and skills. Typically, CVs for entry-level candidates are longer than resumes – at least two or three pages. CVs for mid-level candidates who have amassed numerous publications tend to run much longer. CVs are thus lengthier than resumes, and include more information, particularly details related to one’s academic and research background.

A resume provides a summary of your education, work history, credentials, and other accomplishments and skills. There are also optional sections, including a resume objective and career summary statement. A resume should be as concise as possible. Typically, a resume is one page long, although sometimes it can be as long as two pages.


DIFFERENCE BETWEEN GUARANTEE AND WARRANTY: 

Guarantee is a commitment made by the manufacturer to the buyer. Just like a guarantor stands behind a loan, the manufacturer stands behind the product. If a product under guarantee is of low quality, it will be either repaired/replaced, or the money paid will be refunded to the buyer.


Warranty is an assurance given by the manufacturers to buyers, that if the product breaks or if there is any problem with the product, the manufacturer will repair the product for free.



DIFFERENCE BETWEEN WATER RESISTANT,WATER REPELLENT AND WATER PROOF:

Water-resistant, this is the lowest level of water protection of the three. If a device is labeled as water-resistant it means that the device itself may be built in such a way that it is more difficult for water to get inside of it, or possibly that it is coated with a very light substance that helps improve the device’s chances of surviving an encounter with water. Water-resistant is something you see commonly among watches, giving it the power to withstand the average hand-washing or light rain shower.

Water-repellent, which is basically just a step up from water-resistant. If a device is labeled as water-repellent it actually possesses the properties in which to, you guessed it, repel water from it, making it hydrophobic. A water-repellent device stands a very high chance of being coated with some form of thin-film nanotechnology, whether that is on the inside, outside, or both, and has a much better chance of standing up to water than your average device. Many companies claim water-repellency, but the term is heavily debated because of all the questions and unpredictable elements associated with it.

Waterproof, on the other hand, describes materials or products that can stand complete submersion without taking in any amount of water. They are suitable for camping, swimming, snowboarding, diving, and many more activities since they can be waterproof to great water depths for a long time. The nature of a waterproof product or material is that it is made with absolutely no holes or pores that might let in water. These products are specifically made for use in environments that have plenty of water. However, on the market today, there are a lot of products that are labeled waterproof but aren’t really waterproof – especially electronic devices. This is especially so because different products have different ‘scales’ or ‘levels’ that determine what should be labeled as waterproof or water-resistant.

Sunday 4 August 2019

KNOW WHY OFF ROAD MOTORBIKES HAVE SPOKE WHEELS !!


You might have seen most of the adventure motorbike uses spoke wheels instead of alloy wheels.We will discuss about the reason in this article.

There are two types of wheels you’ll see with modern motorcycle: wire-spoked wheels and alloy wheels.From first commercial motorcycles in the early-1900s up until about the late-’60s, wire-spoke wheels were majorly used.Then we shifted to alloy wheels and now a days a major portion of manufacturers are using alloy wheels.But still you will see most of the bikes use spoked wheels.They come under the category of Adventure Bikes such as Royal Enfield Himalayan,Trimph Tiger,Hero Xpulse,BMW R 1250 GS etc.


Spoked wheels are all but mandatory on off-road bikes — dirt bikes, enduros, scramblers and ADVS — for one simple reason: spoked wheels are more durable than single piece cast wheels. On the road, while riding around on your street bike, you (hopefully) don’t encounter large rocks or massive ruts — maybe the occasional pothole,but these are adventure bikes are made for rough terrains where alloy may bend.Once alloy is bend it can't regain its shape whereas spoked wheels can bend and flex to a certain degree letting you tackle the rougher terrain.Also these spokes increase the torsional strength of the wheel.The number of times a spoke crosses other spokes on the same side increases torsional strength.





In short,adventure bikes are made for rough terrains wherein they require a wheel that can be ductile and this is fulfilled by spoke wheels.The spokes of spoke wheel take major portion of shock and prevents the deformation of wheel.

Monday 29 July 2019

KNOW WHY STONES ARE NOT LAID ON METRO TRACK UNLIKE OTHER TRACKS !!

 
You might have observed that stones are laid beside railway tracks but when it comes to metro tracks,there are no stones laid near the track.We will discuss the reason for this in this article.

Let us first discuss why stones are placed near the railway track.The crushed stones you see alongside railroad tracks are what is known as ballast. Track ballast is packed between the sleepers, in the areas below, and on the sides of railway tracks. A railway sleeper is a rectangular support that is usually kept perpendicular to the tracks. The ballast distributes the load of the sleepers (which in turn bear the load of the train on the track, held by clips) across the foundation, allows for ground movement, thermal expansion and weight variance, allows rain and snow to drain through the track, and prevent the growth of vegetation that would quickly take over the track.
 

When it comes to metro track,it uses ballastless track.Ballastless tracks have different designs to absorb the vibration.They have high initial costs but less maintenance costs. That is why their whole life cost is lower than ballasted tracks. 
 
Since the metro tracks are elevated, drainage and growth of vegetation aren't much of an issue, and the solid structure are designed to bear the wheel loads, and transmit them safely to the earth, there is no requirement of using ballast underneath the track.
There are safety & maintenance issues as well for using ballasts on the elevated sections, as they do pose the risk of flying off and hitting people using the space in the vicinity of the viaducts.
Another reason is that speed is very limited in metro as stations are very close ,that is why impact load is less (for which ballast is used).


Why Railways use ballasted track?


1.Ballasted track is good in the normal speed railway and fast speed railway.

2.Ballasted track requires low investment cost.

3. Ballasted track is usually easy to lay.

4.Ballasted track has good drainage performance.

5.Non-ballasted track cannot be laid in some area like clay deep cutting.





Nevertheless, whenever Rapid transit systems run on the ground, they use traditional methods of load distribution involving sleepers and track ballasts because they are much economic as compared to constructing reinforced concrete girders at places where the latter are not required. Such examples can also be found in Delhi Metro. At sections near Yamuna bank station on blue line, Delhi Metro runs on the ground and uses traditional track ballast.

Sunday 28 July 2019

KNOW WHY POINTED STONES ARE PLACED ON RAILWAY TRACKS !!

Traveling by train is an amazing experience in itself. You get an amazing view of nature. One more thing that you almost always see throughout your train-journey are those small stones lying alongside the track on which your train races?

Have you ever given any thought as to why there are almost always stones alongside a railway track? We will discuss the reason behind this in this article.

The crushed stones you see alongside railroad tracks are what is known as ballast. Track ballast is packed between the sleepers, in the areas below, and on the sides of railway tracks. A railway sleeper is a rectangular support that is usually kept perpendicular to the tracks. These are usually made of wood or pre-stressed concrete, although the latter is more widely used today. The function of railway sleepers is to hold the rails upright and properly spaced. In short, their purpose is to hold the sleeper ties in place, which in turn hold the rails in place.

The rail track is subjected to heat expansion and contraction, ground movement and vibration, precipitation build-up from rough weather, and plant growth from underneath. The ballast distributes the load of the sleepers (which in turn bear the load of the train on the track, held by clips) across the foundation, allows for ground movement, thermal expansion and weight variance, allows rain and snow to drain through the track, and prevent the growth of vegetation that would quickly take over the track.



WHY CRUSHED POINTED STONES ARE USED??

If you put smooth, round pebbles in the ballast, then they might roll or slide over each other when a train passes over the tracks; therefore, they would fail at their main job – providing solidarity to the tracks. Given that fact, you need stones of a specific type that won’t move around too much, except by kids chucking stones near the tracks, of course!

In order to guarantee that the stones stay in place, they use sharp and edged stones in the ballast.