title: Single- and dual-fiber fluorescence probes: application to oil-film measurements in an internal combustion engine.
abstract: Single- and dual-fiber fluorescence probes have been utilized to study oil-film behavior in a firing Diesel engine. A detailed analysis of the response characteristics of these probes was performed, and universal response curves have been generated through identification of the appropriate nondimensional parameters. For single-fiber probes a single curve was obtained, and for dual-fiber probes families of curves were identified based on three geometric dimensionless parameters. The complementary response characteristics of the single- and dual-fiber probes allows determination of the oil distribution within the piston-liner gap. The dual-fiber probe is not sensitive at small distances. Thus its signal originates solely from the piston surface, whereas the single-fiber probe is most sensitive at small distances and hence to the wall oil film. The engine data from the dual-fiber probe confirmed the presence of an oil film on the piston and provided a means of quantifying the transport of this oil within the engine.
authors: Engine Research Center, University of Wisconsin-Madison, 1500 West Engineering Drive, Madison, Wisconsin 53706, USA. ghandhi@engr.wisc.edu
authors: J B
authors: JB
authors: Ghandhi