CHAPTER 1

1 INTRODUCTION

The technology of turbocharger has been used with internal combustion engines since 1905

when Alfred Buechi initiated the idea of using turbocharger with big sized diesel engines such as

boats. In 1920, a smaller sized turbocharger was used with airplanes of France and the US. Then,

in 1923, a low-pressure turbocharger was invented to be used with both four-stroke and two

stroke diesel engines, respectively (Summers, 2007). While previously mainly having been

applied to diesel engines, the market for turbocharged gasoline engines started to take off

around 10 years ago. As emission regulations became stricter, the application of turbochargers

provided a perfect solution for downsizing by reducing the fuel consumption without penalty in

engine performance and drivability.

1.1 TURBO EXPLANATION

A turbocharger is applied to make an engine more efficient, and makes it possible to "downsize"

the engine to a smaller size without any loss in performance. This is why many cylinder 6 engines

have become cylinder 4 engines and so forth. A smaller engine is by definition a cleaner engine

so the application of turbochargers leads to reduced emissions. Nowadays it is almost impossible

in the European Automotive Industry to live up to the emission norms without applying a

turbocharger. A turbocharger utilizes the large amount of energy remaining in the exhaust gas of

the combustion, by using this energy to propel a turbine wheel. On the other end of the turbine

shaft a compressor wheel is mounted. The spinning compressor wheel sucks in fresh air through

the air filter and then blows compressed air to the engine cylinders, first cooled by the

intercooler. The extra oxygen contributes to an optimized combustion inside the engine

significantly improving both fuel economy and emissions.