Category Every Day Science

WHAT ARE THE MAIN SYSTEMS OF A CAR?

Like the human body, a car can be thought of as having systems with different functions, all working together to make the vehicle operate effectively.

 The modern vehicle is made up of a variety of parts and components all working together to achieve a final product: “The Car”. These parts and  components are assembled in groups to perform various tasks. These groups are referred to as systems. There are many systems that make up the modern vehicle, some working with others to perform a larger, sometimes more complex, task and others working individually in order to accomplish an individual job. The following is a list of the major systems that make up the modern vehicle.

  • The Engine – including lubrication and cooling.
  • The Fuel System – including evaporative emission.
  • The Ignition System
  • The Electrical System – including starting and charging.
  • The Exhaust System –including emission control.
  • The Drive Train – including the transmission.
  • The Suspension and Steering Systems
  • The Brake System
  • The Frame and Body

There are many other systems which contribute to the modern vehicle such as the Supplementary Restraint System (seat belts and air bags), Climate Control System (designed to provide passengers with a comfortable environment in which to ride) and everybody’s favourite the Sound System.

THE ENGINE

The engine is the vehicle’s main source of power. This is where chemical energy is converted into mechanical energy. The most popular type of engine is referred to as the Internal Combustion Engine. This engine burns an air/fuel mixture inside itself in order to drive a series of pistons and connecting rods that in turn rotate a crankshaft providing us with a continuous rotating motion with which to drive the vehicle and other components. The engine also incorporates others systems, including the lubrication system and the cooling system, all working efficiently together. The cooling system maintains the engine at an ideal operating temperature while the lubrication system ensures that all the moving parts are kept well-oiled in order to provide a long serviceable life.

Electrical system

As well as moving the wheels, the engine also powers an alternator, or dynamo, which generates electrical current. This current is stored in the battery. This supplies energy for the car’s lights, windscreen wipers, radio and such features as electric windows.

Suspension system

The suspension is a system of springs and shock absorbers that prevents every jolt caused by an uneven road surface being felt by the driver and passengers inside the car.

Transmission system

The transmission system consists of the crankshaft, gears and the differential. This is a system of gears on the axles that allows the wheels to travel at different speeds when going round corners, when the outer wheel travels further than the inner one.

Braking system

Each wheel has a brake unit, connected to the brake pedal by a tube full of brake fluid. Pushing the pedal forces the fluid down the tube, causing a brake shoe to press against a metal disk or drum on the inside of the wheel. Friction causes the wheels to slow and stop.

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HOW DOES THE INTERNAL COMBUSTION ENGINE WORK?

Internal combustion engines are usually fuelled by petrol or diesel. This fuel is burnt (combusted) within metal cylinders. The burning fuel causes a piston to move up and down inside each cylinder, and it is this upward and downward movement that is translated into a turning movement by the crankshaft, causing the axles and wheels to turn and the car to move.

Combustion, also known as burning, is the basic chemical process of releasing energy from a fuel and air mixture.  In an internal combustion engine (ICE), the ignition and combustion of the fuel occurs within the engine itself. The engine then partially converts the energy from the combustion to work. The engine consists of a fixed cylinder and a moving piston. The expanding combustion gases push the piston, which in turn rotates the crankshaft. Ultimately, through a system of gears in the powertrain, this motion drives the vehicle’s wheels.

There are two kinds of internal combustion engines currently in production: the spark ignition gasoline engine and the compression ignition diesel engine. Most of these are four-stroke cycle engines, meaning four piston strokes are needed to complete a cycle. The cycle includes four distinct processes: intake, compression, combustion and power stroke, and exhaust.

Spark ignition gasoline and compression ignition diesel engines differ in how they supply and ignite the fuel.  In a spark ignition engine, the fuel is mixed with air and then inducted into the cylinder during the intake process. After the piston compresses the fuel-air mixture, the spark ignites it, causing combustion. The expansion of the combustion gases pushes the piston during the power stroke. In a diesel engine, only air is inducted into the engine and then compressed. Diesel engines then spray the fuel into the hot compressed air at a suitable, measured rate, causing it to ignite.

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WHICH WAS THE FIRST CAR?

In 1769 the first steam-powered automobile capable of human transportation was built by Nicolas-Joseph Cugnot.

In 1808, Hyden Wischet designed the first car powered by the de Rivaz engine, an internal combustion engine that was fueled by hydrogen.

In 1870 Siegfried Marcus built his first combustion engine powered pushcrt, followed by four progressively more sophisticated combustion-engine cars over a 10-to-15-year span that influenced later cars. Marcus created the two-cycle combustion engine. The car’s second incarnation in 1880 introduced a four-cycle, gasoline-powered engine, an ingenious carburetor design and magneto ignition. He created an additional two models further refining his design with steering, a clutch and a brake.

The four-stroke petrol (Diesel) internal combustion engine that still constitutes the most prevalent form of modern automotive propulsion was patented by Nikolaus Otto. The similar four-stroke Diesel engine was invented by Rudolf Diesel. The hydrogen fuel cell, one of the technologies hailed as a replacement for gasoline as an energy source for cars, was discovered in principle by Christian Friedrich Schonbein in 1838. The battery electric car owes its beginnings to Anyos Jedlik, one of the inventors of the electric motor, and Gaston Plante, who invented the lead-acid battery in 1859.

In 1885, Karl Benz developed a petrol or gasoline-powered automobile. This is also considered to be the first “production” vehicle as Benz made several other identical copies. The automobile was powered by a single cylinder four-stroke engine.

In 1913, the Ford Model T, created by the Ford Motor Company five years prior, became the first automobile to be mass-produced on a moving assembly line. By 1927, Ford had produced over 15,000,000 Model T automobiles.

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WHAT WERE THE FIRST BOATS LIKE?

It is likely that the first boats were made of hollowed-out tree trunks. Perhaps early humans saw fallen hollow logs floating along a river and realized that they could carry goods and people. Tree trunks were hollowed using stone axes and fire. A dugout pine canoe, found in the Netherlands, is thought to be at least 8000 years Old.

The oldest discovered boat in the world is the 3 meter long Pesse canoe constructed around 8,000 BCE; but more elaborate craft existed even earlier. A rock carving in Azerbaijan dating from ~10,000 BCE shows a reed boat manned by about 20 paddlers. Others argue that hide boats (kayaks) were used in Northern Europe as early as 9,500 BCE.

Nothing remains of these early boats – which have long since rotted away; but, knowing what plants and tools were available at the time, anthropologists can guess at the kinds of watercraft they used. The current theory is that bamboo rafts like the one shown below were used. Recently, this hypothesis was tested by building rafts using Stone Age techniques and replicating critical crossings.

It’s easy to characterize the Vikings as bloodthirsty reprobates rampaging across Europe, but the craft and innovation of the shipbuilding that enabled their conquests deserves recognition.

The fact that Leif Erikson led a Viking crew to North America in around 1,000 — 500 years before Christopher Columbus set foot on the New World — makes clear the Vikings’ remarkable maritime prowess and showcases the robustness of their boats.

The design principles that led to the Viking longship can be traced back to the beginning of the Stone Age and the umiak, a large open skin boat used by Yupik and Inuit people as long as 2,500 years ago.

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HOW DOES A YACHT TACK?

Sailors cannot change the direction of the wind, but thin they are not powerless to change the direction of their sailing boats. By steering a zigzag course, called tacking, they are able to sail in the direction they require. This can be a time-consuming process. It is important that the navigator keeps an accurate check on the boat’s position, so that it does not travel too far off course while tacking.

If your destination lies upwind, how do you sail there? Unless the wind is blowing from directly astern (over the back of the boat), the sails propel the boat forward because of “lift” created by wind blowing across them, not by wind pushing against them. As you steer more toward the wind direction, you trim the sails in tighter to keep them full, and keep generating lift. But sail too close to the wind and the sail will “luff”— the forward edge will start to flutter in and out and the boat will slow down. Turn more into the wind and soon the whole sail will be flapping like a bed sheet hanging out to dry. But keep turning through the wind and soon the sail will fill on the other side of the boat. This is called “tacking.”

Modern sailboats can sail up to about a 45-degree angle from the wind. For example, if the wind is blowing from the north, a boat can sail from about northeast on port tack (“tack” also describes which side of the boat the wind is blowing from: “port tack” means the wind is coming over the port, or left, side) all the way through east, south and west to northwest on the starboard tack (wind coming over the right side of the boat).

On the new tack, you’ll find you’re sailing in a direction that’s at about right angles to the old tack, with the wind still at about 45 degrees, but now on the other side. Tack again and again and the zigzagging will move the boat upwind, even though the boat can’t sail directly into the wind. Sailors call this “beating,” or “tacking,” to windward, and doing it efficiently takes more skill and practice than anything else in sailing. But learn to do it well and you can sail anywhere.

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WHY ARE PORT AND STARBOARD SO CALLED?

Traditionally, the left hand side of a ship, looking forward, is called the port side, while the right hand side is called the starboard side. The term “starboard” comes from “steerboard”. The large oar used to steer early ships was usually on the right. “Port” comes from the fact that ships had to tie up on the left side in port so that their steering oar would not be crushed against the dock.

Since port and starboard never change, they are unambiguous references that are independent of a mariner’s orientation, and, thus, mariners use these nautical terms instead of left and right to avoid confusion. When looking forward, toward the bow of a ship, port and starboard refer to the left and right sides, respectively.

In the early days of boating, before ships had rudders on their centerlines, boats were controlled using a steering oar. Most sailors were right handed, so the steering oar was placed over or through the right side of the stern. Sailors began calling the right side the steering side, which soon became “starboard” by combining two Old English words: stéor (meaning “steer”) and bord (meaning “the side of a boat”).

As the size of boats grew, so did the steering oar, making it much easier to tie a boat up to a dock on the side opposite the oar. This side became known as larboard, or “the loading side.” Over time, larboard—too easily confused with starboard—was replaced with port. After all, this was the side that faced the port, allowing supplies to be ported aboard by porters.

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