PULSE PLUG - AN INNOVATION IN SPARK PLUG ERA

Everyone is familiar about spark plugs. A brand called 'Pulstar' launched a new kind of spark plug called as pulse plug. Pulse plugs - a different innovation in spark plug technology and design acclaims to increase horsepower and fuel efficiency. The new pulse plug produces a stronger and wider spark when compared to the existing spark plugs. Generally the main work of the spark plugs is to ignite the charge (air and fuel) in gasoline engines. The more better and complete combustion of charge also drastically increases the horse power and efficiency. In this post lets see about the technology behind pulse plugs in comparison with existing the spark plugs.

Spark plugs work similar to a lightning bolt in clouds. To create a spark the power should have a very high voltage in order to travel across the electrode and create a good spark. 

Voltage at the spark plug can be anywhere from 40,000 to 100,000 volts. This high voltage is usually produced by an induction coil. This induction coil is similar to a step-up transformer to produce a high voltage discharge.

The high voltage from the induction coil is supplied to the spark plug by the spark plug cable and a spark is created between the electrodes of the spark plug.

In pulstar spark plug, a capacitor space is included in the plug which boosts the voltage when compared to an ordinary conventional spark plug. This high voltage discharge produces a wider and better spark. But it is not 100% guaranteed that it improves HP and fuel efficiency. Normally a new spark plug performs better compared to the old one, so it is tough to decide which is a better one.

NGK iridium spark plugs produce a consistent and steady spark area which improves performance. It lasts longer than ordinary spark plugs. The Pulstar pulse plugs are usually larger in size and pricy too, plus they don't have fit properly in many vehicles. Not available in our country.

The only advantage of using a pulse plug is that it can produce a spark with larger area. Hence the combustion becomes complete even the charge (air & fuel mixture) is lean or rich.

VOLKSWAGEN'S BLUEMOTION TECHNOLOGY - EXPLAINED

We might have come across the ads in tv and other media stating as Volkswagen Bluemotion Technologies. This technology for which Volkswagen has exclusively developed for its automobiles was quite impressive. In German 'Volks' means people and 'Wagen' means car. So together, it's called people's car. Similarly the Bluemotion technology also has its meaning. 'Blue' personifies our blue planet Earth and 'Motion' refers to the movement of automobiles.

This technology is based on the theme of using eco friendly measures and ideas to protect and conserve the environment without compromising the performance of automobiles. Therefore it's an important milestone and also a complete set of new innovations for green tomorrow. Many environmental issues like global warming, climatic changes, Ozone depletion, etc are caused due to increased level of carbon emissions from automobiles. 

The Bluemotion technology has been developed by taking all these factors into account and it puts its solution in their automobiles. 

This technology entirely focuses on the following areas such as,

• Engine with new technology and revised engine mapping to provide minimal carbon emissions.
• Transmission systems with optimized gear ratios assisted in a perfect way of delivering power seamlessly.
• The auto start-stop system.
• Bi-fuel engines using conventional fossil fuels in combination of LPG (Liquified Petroleum Gas) & CNG (Copmressed Natural Gas).
• Brake energy regeneration.
• Producing Hybrid and electric automobiles.
• Using low rolling resistance tyres.

Engine Technology: The newly developed TSI (Turbo and Stratified Injection) & TDI (Turbo Direct Injection) are extremely economical. The fundamental characteristics shared by all TDI engines are high-pressure fuel injection and variable turbine geometry for excellent cylinder charging and an efficient combustion process. At the same time, Volkswagen is increasingly deploying innovative common-rail technology.

Pioneering technology is used in the TSI engines, combining direct petrol injection with a turbocharger or charge compression with both a turbo and a supercharger, enabling them to deliver impressive performance figures and torque and to provide the driver with the full spectrum of driving pleasure despite the smaller engine. The combustion of the petrol is particularly efficient, with the result that the power output of the TSI engines is considerably higher than is the case with conventional, naturally aspirated engines.

Transmission systems: The innovative DSG dual-clutch gearbox from Volkswagen offers previously unattained shifting comfort that lifts what were once well-defined boundaries between automatic and manual transmissions. This is a 6-speed gearbox that combines the sporty character and low fuel consumption of a manual gearbox with the comfort and convenience of an automatic. Another highlight: gear changes are executed without any interruption of the driving power.

The auto-stop system: The Start/Stop system means your car can virtually stop its engine by itself. It works through the clutch, so when you come to a standstill, you just select neutral gear, release the clutch and the engine switches off with a Start/Stop symbol appearing on the dashboard. When you want to move off again you simply dip the clutch, the engine restarts and you can select first gear and pull away. The system can easily be deactivated, if you wish, by a switch within easy reach.

Bi-fuel engines: Bi-Fuel is a so-called hybrid powertrain developed for smaller, popular models (such as the Golf and Golf Plus). This means that you can use a second fuel in addition to the main fuel type: in this case LPG (Liquefied Petroleum Gas). Helping you “drive” down costs while offering unique flexibility at the same time.

Brake energy regeneration: The alternator voltage is increased when slowing down and braking. This increases battery charging and helps the car slow down. The alternator load is then reduced when accelerating to lighten the burden on the engine and cut fuel consumption. It Recovers and uses the energy produced by braking, reducing fuel consumption and emissions.

Hybrid and electric cars: The next concept is to produce new type of hybrid and electric cars. Hybrid cars are fuel economical and eco friendly. The designing of electric cars providing the ease of use of like conventional cars is being carried out.

Low rolling resistance tyres: Low rolling resistance tyres are part of BlueMotion Technologies. They need less engine power to move the car forward, saving fuel and helping to cut emissions, while still offering excellent performance.

Some of the existing models equipped with Bluemotion technology areNew Polo,Passat.Toura,New Beetle.

OCTANE NUMBER AND CETANE NUMBER EXPLAINED

Octane number (octane it means eight carbon atoms )

Octane number is used in petrol engines. It determines how much compression ratio a petrol mixture can withstand. If the limit is crossed the fuel will spontaneously ignite and its called knocking.

Generally octane numbers range from 87 - 90 . If that number is high then the petrol can withstand higher compression ratio. But it comes with more cost.

The number 87 denotes 87 % of octane and rest is heptane ( it can withstand only very lower compression ratio) , that's why as octane number increases the engine can have higher compression ratios.

Octane the name comes because its major composition of petrol.

Cetane number ( 16 carbon atoms )

Its for diesel engine due to composition of diesel has mostly 16 carbon atoms. Its just opposite of octane number.

It determines how fast the fuel will enter combustion stage. It signifies the time gap between time of injection and time of ignition of a diesel. Higher cetane number means this gap is less.

So why you need higher cetane fuel

Fuel is generally injected few degree of crank before piston hits TDC. If cetane number is less the fuel will combust at a time when the pistion would have already left far from TDC. So you dont get enough torque and milegae will be less. So if fuel ignites earlier there will more time for expansion.

Cetane numbers are between 40 - 48

COOLING TOWER EXPLAINED

A cooling tower is a heat rejection device, which rejects waste heat to the atmosphere though the cooling of a water stream to a lower temperature. The type of heat rejection in a cooling tower is termed "evaporative" in that it allows a small portion of the water being cooled to evaporate into a moving air stream to provide significant cooling to the rest of that water stream. The heat from the water stream transferred to the air stream raises the air's temperature and its relative humidity to 100%, and this air is discharged to the atmosphere. 

Evaporative heat rejection devices such as cooling towers are commonly used to provide significantly lower water temperatures than achievable with "air cooled" or "dry" heat rejection devices, like the radiator in a car, thereby achieving more cost-effective and energy efficient operation of systems in need of cooling. Think of the times you've seen something hot be rapidly cooled by putting water on it, which evaporates, cooling rapidly, such as an overheated car radiator. The cooling potential of a wet surface is much better than a dry one.

Common applications for cooling towers are providing cooled water for air-conditioning, manufacturing and electric power generation. The smallest cooling towers are designed to handle water streams of only a few gallons of water per minute supplied in small pipes like those might see in a residence, while the largest cool hundreds of thousands of gallons per minute supplied in pipes as much as 15 feet (about 5 meters) in diameter on a large power plant.

Some useful terms, commonly used in the cooling tower industry:

Drift - Water droplets that are carried out of the cooling tower with the exhaust air. Drift droplets have the same concentration of impurities as the water entering the tower. The drift rate is typically reduced by employing baffle-like devices, called drift eliminators, through which the air must travel after leaving the fill and spray zones of the tower.

Blow-out - Water droplets blown out of the cooling tower by wind, generally at the air inlet openings. Water may also be lost, in the absence of wind, through splashing or misting. Devices such as wind screens, louvers, splash deflectors and water diverters are used to limit these losses.

Plume - The stream of saturated exhaust air leaving the cooling tower. The plume is visible when water vapor it contains condenses in contact with cooler ambient air, like the saturated air in one's breath fogs on a cold day. Under certain conditions, a cooling tower plume may present fogging or icing hazards to its surroundings. Note that the water evaporated in the cooling process is "pure" water, in contrast to the very small percentage of drift droplets or water blown out of the air inlets.

Blow-down - The portion of the circulating water flow that is removed in order to maintain the amount of dissolved solids and other impurities at an acceptable level.

Leaching - The loss of wood preservative chemicals by the washing action of the water flowing through a wood structure cooling tower.

Noise - Sound energy emitted by a cooling tower and heard (recorded) at a given distance and direction. The sound is generated by the impact of falling water, by the movement of air by fans, the fan blades moving in the structure, and the motors, gearboxes or drive belts.

CLASSIFICATION OF ENGINE ON THE BASIS OF BORE STROKE RATIO

The engine capacity is measured as Bore x Stroke. Here, Bore is the diameter of the cylindrical block and Stroke is the depth of the cylindrical block, as shown in the image.

When stroke/bore value is over 1:1 the engine is long-stroke or undersquare and when the stroke/bore value is under 1:1 the engine is short-stroke or oversquare. The square engine has a value of 1:1 in both cases.

For example an engine with 110 millimetres (4.33 in) stroke and 80 millimetres (3.15 in) bore, stroke/bore value 1.375, is an undersquare or long-stroke engine. An engine that has 70 millimetres (2.76 in) stroke and 100 millimetres (3.94 in) bore, stroke/bore value 0.7, is oversquare or short-stroke.

The stroke ratios are generally based under 3 catagories depending on the different ratios,

• Short stroke/Over square engine
• Long stroke/Under square engine
• Square engine

Short Stroke/Over square Engine:

As the name signifies the Stroke is shorter than the Bore. Due to the relatively shorter stroke, the engine revs fast and is more suitable where a quick build of power is important, more importantly where the bikes make power at higher rpms.

An oversquare engine allows for more and larger valves in the head of the cylinder, lower friction losses (due to the reduced distance travelled during each engine rotation) and lower crank stress (due to the lower peak piston speed relative to engine speed). Because these characteristics favor higher engine speeds, oversquare engines are often tuned to develop peak torque at a relatively high speed.

Short stroke engines revs faster and hence produce more power. It makes the bike very responsive which is very essential in racing bikes. Also the short stroke engines have a very narrow power range and hence requires very short gear ratios to keep them in power range.

Some examples:

• Apache RTR 180 (62.5mm X 57.8 mm) Bore x Stroke.
• Pulsar 220 (67mm X 62.4 mm), 180(63.5mm X 56.4mm) Bore x Stroke.

Formula 1 engines use short stroke designs because it allows the engine to rev higher. Because of this, they are capable of generating greater horsepower. Sports bikes and their racing version use short stroke engines.

Long Stroke/ Under square Engine:

As the name suggests the Stroke is longer than the Bore. Due to the longer stroke, the engine makes good torque at relatively low rpms. It is important where the bikes’ pulling more (torque) at relatively low rpms is more important than the top speed.

At a given engine speed, a longer stroke increases engine friction (since the piston travels a greater distance per stroke) and increases stress on the crankshaft (due to the higher peak piston speed). The smaller bore also reduces the area available for valves in the cylinder head, requiring them to be smaller or fewer in number. Because these factors favor lower engine speeds, undersquare engines are most often tuned to develop peak torque at relatively low speeds.

Long stroke engine are usually used in heavy vehicles and they wont rev fast. But they are very durable and have a much broad power range which requires few gears.

Some examples:

• Royal Enfield Classic 500 (84mm X 90mm), Classic 350 (70mm X 90 mm)
• Hero Honda Karizma (65.5mm X 68.2mm)

Square Engine: 

As a square has both the sides equal, here also the Bore and Stroke are of almost same size.The engine tries to strike a balance between torque and top speed.

An engine is described as a square engine when it has equal bore and stroke dimensions, giving a bore/stroke value of exactly 1:1.

For example an engine which has 95 millimetres (3.74 in) bore, and an identical 95 millimetres (3.74 in) stroke, has a bore/stroke value of:

95 mm / 95 mm = 1.00

Square engines combines both the worlds, perfect for daily commuting with great mileage figures.

Some Examples:

• Yamaha FZ-16 (58mm X 57.9mm)
• Honda Unicorn (57.3mm X 57.8mm)

NITROGEN IN TYRES : PROS AND CONS

A few years ago, the use of nitrogen in tyres had been introduced. The idea was to replace the free air provided at petrol pumps with Nitrogen gas for a nominal charge. The concept did not gain much mileage and nitrogen gas providers shut down at some places.

But today, there are many 250cc bikes available in the market. The price of high speed bikes is well within the reach of the middle class consumer. At continuous high speeds, the tyres in these bikes can inflate quickly. Here, tyres filled with nitrogen gas prove their superiority over tyres filled with air. Let’s have a look at the benefits and shortcomings of nitrogen in tyres.

Advantage of nitrogen in tyres:

–    Nitrogen is lighter than air. So, the bounce you feel sometimes at high speeds is reduced to a very great degree. This translates into a smoother ride for you.

–    Nitrogen gas remains cool, which is a characteristic trait of the element. So the temperature of the tyres while riding at high speeds also remains cooler compared to air.

–    The tyre pressure remains constant at different speeds regardless of heavy / light load on the vehicle. It remains quite stable regardless of the temperature of the tyre.

–    The life of the tyre gets an extension. Since the wear and tear has slowed down, the durability of the tyre increases.

–    There is also a noticeable reduction in rusting of the rims or wheel as nitrogen is chemically inactive.

–    The rate of nitrogen pressure leaking from the tyre is 10 times less than the compressed air. So one can fill the tyres with nitrogen gas and then check the pressure again after 3-4 months or even more.

There are not many disadvantages of nitrogen in tyres but those that exist cannot be ignored.

–    The process is expensive. When it was introduced, it cost approximately Rs.100 for a two-wheeler and the cost was double for a four-wheeler.

–    Even today the gas is not available widely. Only a handful of tyre dealers provide it.

–    It’s useful for high speed bikes. Compared to the amount of commuter bikes the ratio is fairly low.

–    If a tyre gets punctured, after repairing the puncture, you have to repeat the process of filling nitrogen in the tyre.

Despite the shortcomings one can still opt to fill their bike tyres with nitrogen and get rid of the risk of tyres running at high temperatures. Perhaps you can even save your tyre from getting burst due to inflation. These advantages surely outweigh any cost disadvantage that nitrogen gas may have.

ALL YOU NEED TO KNOW ABOUT UNIT AND UNIT CONVERSION

UNIT CONVERSION