Particle Image Velocimetry (PIV) is now emerging as a powerful tool for the
investigation of unsteady fluid mechanics. At the same time, the study and optimisation
of in-cylinder flow processes in automotive Internal Combustion (IC) engines is of
increasing importance in the design of improved combustion systems with lower
emissions and favourable power and efficiency characteristics.
This thesis describes the development and application of PIV as a routine diagnostic tool
for the investigation of in-cylinder flows in a production geometry single cylinder
research engine exhibiting "barrel swirl" or "tumbling" in-cylinder fluid motion. The
work has involved the design and installation of a complete PIV engine facility, based
around a four-valve, four-stroke Rover research engine equipped with piston crown
optical access and a glass cylinder liner. Novel techniques for the on-line monitoring of
important experimental parameters have been developed which permit the reliable
acquisition of high spatial resolution PIV data from both horizontal and vertical
measurement planes within the engine cylinder. A novel optical correction technique has been developed to control the severe particle
image degradation which was experienced when imaging vertical planes within the glass
cylinder. A simple means for selection of an appropriate corrective lens for this
application is described, together with an experimental evaluation of the lens
A representative set of PIV images and data from both horizontal and vertical planes are
then presented. These have been selected from a comprehensive set of flow mapping
experiments in the motored engine. The data are discussed with reference to the work of
others in engines of similar geometry and have shed new light on the detailed processes
involved in the formation and breakdown of barrel swirl.
Initial PIV measurements ahead of a flame under part load, skip fired conditions have
also been made in the engine. This has demonstrated the possibility of investigating incylinder
flow behaviour under conditions approaching those in a fully firing, production
geometry optical engine. Finally, limitations in the PIV technique employed in this work and methods of overcoming them are described and the prospects for further work are discussed.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.