Transient response performance of an engine turbocharger
This thesis is concerned with predicting the transient response performance of an exhaust gas turbocharger under pulsating and non-pulsating flow conditions. Using the measured steady state characteristics of the turbocharger compressor and turbine, theoretical procedures are developed to predict its transient response during rapid variations in the turbine inlet conditions. A computer program has been written for non-pulsating and two other programs for pulsating flow conditions. Each of these programs used a different method of predicting the response. The programs, with their subroutines and the organization of the calculations, and experimental data are presented. To enable the computer predicted results to be compared with experimental results, an experimental program was carried out on a Holset 3LD turbocharger. The layout and the principal features of the experimental test rig, which is designed to operate the turbocharger from a compressed air supply, are described. The rig may be used to simulate engine exhaust conditions. The computer predicted results are compared with the experimental ones obtained from tests, during pulsating and non-pulsating operation of the turbocharger. The experimental results and theoretical predictions are found to compare favourably, and the possible causes of discrepancies are suggested. Suggestions are made for further work.