How do Turbochargers Work

A turbocharger, quite often referred to as turbo, is a mechanical gas compressor, used to facilitate forced induction of an internal combustion engine. The turbocharger increases the density of air which enters the engine to create extra power. The turbine which powers the compressor in the turbo charged engine is driven by the exhaust gases from the engine. Usually, a turbocharger is made up of a compressor and a turbine on a shared shaft. The heat which is converted into rational force by the turbine, is used to drive the compressor wheels.

The turbocharger was invented by Alfred Buchi, a Swiss engineer. It is one of the most effective way of producing power from an internal combustion engine, and hence is quite popular in automotive, marine and aviation industries. By far, the biggest advantage of a turbocharger is the fact that it adds to the engine capacity without adding weight to it.

Turbochargers: How do they Work?

Turbochargers work on the basic principle 'more the air is drawn into the engine, more the power is generated during the combustion phase'. In this mechanism, the exhaust gases, which contain unburnt air and fuel, are redirected to the turbine wheel by a series of pipes. The turbine wheel is connected to the compressor by a shaft on one end of the housing. This housing, referred to as a turbocharger, has two wheels on the either ends. The exhaust gases cause the turbine wheel to spin, and this triggers the spinning of compressor wheel which is connected to turbine wheel.

As the compressor wheel accelerates, exhaust gases are continuously drawn into the turbo housing and compressed. The compressor wheel spins at the speed of about 150,000 revolutions per minute as a result of which the exhaust gases get compressed very quickly. This compressed air is then directed back into the intake system. As a result of this enormous amount of heat is produced. Low density molecules are produced because of these hot gases. To avoid this, most modern turbocharger systems sport an inter cooler, a device resembling the radiator, which works as a coolant to cool the air leaving the turbo housing.

As the temperature of gases which leaves the turbo housing is low, the density of air molecules becomes high. This cooler air is redirected back into the main intake system, due to which the engine produces more power during the process of combustion. The same process is repeated continuously as a result of which the pressure of the engine increases. This has the tendency to harm the engine, and to avoid this a component known as the wastegate is added to the turbocharger. When the pressure exceeds a particular level, the wastegate opens to vent excess heat. This preset pressure in the turbo engines is referred to as 'boost level'. Higher the boost level, more the power is produced.

Turbochargers have been in use for over a century now, and the mechanism has only evolved with time. Today, the technology is used in various high performance vehicles ranging from sports utility vehicles to a customized racing cars. One of the most prominent difference between supercharger and turbocharger is the fact that former is powered by engine torque and latter by engine exhaust. In terms of efficiency, a turbocharged engine is considered to be better than a supercharged engine as it harnesses the energy in the exhaust stream which would otherwise go wasted.