Improvement of LIEF by wavelength-resolved acquisition of multiple images using a single CCD detector – Simultaneous 2D measurement of air/fuel ratio, temperature distribution of the liquid phase and qualitative distribution of the liquid phase with the Multi-2D technique

Abstract

The exciplex tracer system fluorobenzene (FB) and diethyl-methyl-amine (DEMA) in a solution of n-hexane and methyl-tert.-butylether (MTBE) was used to investigate the mixture formation in a fired direct injection spark ignition engine. The scope of this paper is the recently developed Multi-2D technique, which allows for the simultaneous measurement of the local air/fuel ratio (λ-distribution of the vapor phase), the qualitative distribution of the liquid phase, the temperature distribution of the liquid phase, and the detection of Mie scattering in this application. Basically, the Multi-2D technique consists of a new optical setup, which images the same field of view four times onto one camera, thus combining spatial and spectral resolution based on interference filters. The liquid temperature is derived via “two-line” thermometry. Using the liquid phase temperature the crosstalk from the liquid into the spectral detection range of the vapor phase is corrected. Quantitative results of the crosstalk-corrected vapor phase signals are achieved by an in-situ calibration.