Abstract
Acceleration of a 4-cylinder, 7-litre, turbocharged diesel engine has been investigated by the means of experimental and analytical procedure. The engine acceleration on a test stand has been tested using standard dynamometer which has been controlled by a computer. All measurements have been performed at the maximum fuel rack position, however the courses of engine load have been varied. Engine speed, dynamometer load, in-cylinder pressure and boost pressure-time history, have been measured during acceleration in order to acquire the data for validation of engine acceleration model. A non-linear, transient, multi-cylinder, turbocharged, diesel engine simulation has been developed for predictions of instantaneous engine and turbocharger speed and torque. The foundation of the model is a thermodynamic, steady state diesel engine simulation. The transient extension of the original model represents the diesel engine as a non-linear, dynamic system. The predictions of engine simulation model agree fairly well with experimental results and may be used for case studies of engine acceleration. As an example the model has been used to study the influence of manifold-pressure compensator (LDA-system) on the acceleration of turbocharged diesel engine. The original LDA-system has been modified and the comparison of the results predicted by the application of original and modified LDA system has been done.
