Abstract
Tunable excimer lasers are used to obtain 2-D images of molecular (and some state-specific) density distributions inside a cylinder of a modified four-cylinder in-line engine that has optical access. Natural fluorescence (i.e., without a laser) is used for some OH pictures, normal laser-induced fluorescence (LIF) for those of NO and of the isooctane fuel, and laser-induced predissociative fluorescence (LIPF) for other OH pictures and for those of O2. Relevant spectroscopy is done to find the laser and fluorescence frequencies needed to measure isolated species. LIPF works well at high pressures, is state specific, and is ideally suited to follow turbulent processes. No similar measurements in engines have been previously reported. Pictures are taken in succeeding engine cycles. Their sequence is either at a particular point of the engine’s cycle to show cyclic fluctuations, or at succeeding portions of the cycle to illustrate the progress of the gasdynamics or of the combustion.
© 1990 Optical Society of America
Full Article | PDF ArticleMore Like This
Erhard W. Rothe and Peter Andresen
Appl. Opt. 36(18) 3971-4033 (1997)
Johan Hult, Mattias Richter, Jenny Nygren, Marcus Aldén, Anders Hultqvist, Magnus Christensen, and Bengt Johansson
Appl. Opt. 41(24) 5002-5014 (2002)
Peter Andresen, Harald Schlüter, Dagmar Wolff, Heiner Voges, Andrea Koch, Werner Hentschel, Winfried Oppermann, and Erhard Rothe
Appl. Opt. 31(36) 7684-7689 (1992)