Jenny Nygren

Learn More
Formaldehyde (CH2O) is an important intermediate species in combustion processes and it can through laser-induced fluorescence measurements be used for instantaneous flame front detection. The present study has focussed on the use of the third harmonic of a Nd:YAG laser at 355 nm as excitation wavelength for formaldehyde, and different dimethyl ether(More)
The Homogeneous Charge Compression Ignition (HCCI) combustion progress has been characterized by means of high-speed fuel tracer Planar Laser Induced Fluorescence (PLIF) combined with simultaneous chemiluminescence imaging. Imaging has been conducted using a high-speed laser and detector system. The system can acquire a sequence of eight images within less(More)
We investigate the applicability of two-line atomic fluorescence (TLAF) from seeded indium atoms for temperature measurements in highly sooting flames. The results show that TLAF holds promise for two-dimensional temperature measurements in sooting and fuel-rich flames under conditions in which other thermometry techniques fail, a result that is attributed(More)
Three-dimensional imaging of fuel tracer planar laser-induced fluorescence in a homogeneous charge compression ignition (HCCI) engine is presented. A high-speed multiple Nd:YAG laser and detection system, in combination with a scanning mirror, are used to collect eight images, with an equidistant separation of 0.5 mm. Three-dimensional isoconcentration(More)
Temperature measurements using planar laser-induced fluorescence (PLIF) are most often associated with experimental challenges. In addition, no PLIF technique is generally applicable in all kinds of environment. Especially under sooting conditions problems are prone to arise, which limits the use of these techniques. In this paper the two-line atomic(More)
High-repetition-rate laser-induced fluorescence measurements of fuel and OH concentrations in internal combustion engines are demonstrated. Series of as many as eight fluorescence images, with a temporal resolution ranging from 10 micros to 1 ms, are acquired within one engine cycle. A multiple-laser system in combination with a multiple-CCD camera is used(More)
This paper reports on the development of novel time resolved spectroscopic imaging techniques for the study of spark ignition phenomena in combustion cells and an SIengine. The techniques are based on planar laser induced fluorescence imaging (PLIF) of OH radicals, on fuel tracer PLIF, and on chemiluminescence. The techniques could be achieved at repetition(More)