Turbocharging of internal combustion engines

Abstract

Turbocharging of internal combustion engines has been extensively employed over the years mainly in the heavy engineering fields. However, it has not, until recently, been given its due importance as being the best possibility of raising an engine's power output whatever the engine, compression or spark ignition, and whatever the discipline in which it is utilised, be it marine, aviation or the simple passenger car engine. The aim of this thesis was to set up a turbocharged engine test rig. This involved the simulation of exhaust turbine and air compressor effects on the basic naturally aspirated engine. This simulation was achieved by using compressed air from an external air compressor and by fitting a fixed area nozzle in the exhaust system. Tests were then carried out to investigate the variation in engine characteristics and comparison with results obtained by others then showed if the simulation was a realistic one. This experimentation is dealt with in the second part of the thesis. The advantages of such a system are obvious in that one can carry out simulated tests on an engine before actually installing a turbocharging unit, thus recording the variation in engine characteristics due to the effects of turbocharging. The first part of the thesis is dedicated to an in depth literature survey into the different turbocharging systems being employed nowadays and their effects together with an investigation of the actual relationships between turbocharger turbine, compressor and the engine.