Christof Schulz

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A new flow tagging technique was developed which visualizes small-scale flow structures by writing a spatial line of NO into an air flow homogeneously seeded with NO2. The NO-line was generated by photodissociation of NO2 at 308 nm using a XeCl excimer laser and was imaged by planar laser-induced fluorescence at various delays after its formation. With(More)
The influence of pressure on laser-induced incandescence (LII) is investigated systematically in premixed, laminar sooting ethylene/air flames at 1-15 bar with wavelength-, laser fluence-, and time-resolved detection. In the investigated pressure range the LII signal decay rate is proportional to pressure. This observation is consistent with the prediction(More)
The specific properties of nanoscale particles, large surface-to-mass ratios and highly reactive surfaces, have increased their commercial application in many fields. However, the same properties are also important for the interaction and bioaccumulation of the nonbiodegradable nanoscale particles in a biological system and are a cause for concern. Hematite(More)
Three different high-pressure flame measurement strategies for NO laser-induced fluorescence (LIF) with A-X(0,0) excitation have been studied previously with computational simulations and experiments in flames up to 15 bars. Interference from O2 LIF is a significant problem in lean flames for NO LIF measurements, and pressure broadening and quenching lead(More)
Laser-induced fluorescence (LIF) of carbon dioxide is investigated with excitation between 215 and 255 nm with spectrally resolved detection in 5–40 bar premixed CH4/O2/Ar and CH4/air flat-flames at fuel/air ratios between 0.8 and 1.9. The LIF signal consists of a broad (200–450 nm) continuum with a faint superimposed structure, and this signal is absent in(More)
A-X(0,1) excitation is a promising new approach for NO laser-induced fluorescence (LIF) diagnostics at elevated pressures and temperatures. We present what to our knowledge are the first detailed spectroscopic investigations within this excitation band using wavelength-resolved LIF measurements in premixed methane/air flames at pressures between 1 and 60(More)
Laser-induced fluorescence (LIF) has proven a reliable technique for nitric oxide (NO) diagnostics in practical combustion systems. However, a wide variety of different excitation and detection strategies are proposed in the literature without giving clear guidelines of which strategies to use for a particular diagnostic situation. We give a brief review of(More)
Laser-induced incandescence (LII) is investigated in laminar premixed flat ethylene/air flames at pressures up to 5 bar in a recently constructed high-pressure burner. Time-resolved LII signals were compared with a numerical model considering the influence of pressure on the LII signal decay. Peak particle temperatures after laser heat up were measured by(More)
A technique based on planar laser-induced fluorescence of 3-pentanone, for measurements of absolute concentration, temperature and fuel/air equivalence ratios in turbulent, high-pressure combustion systems such as an internal combustion engine is presented. Quasi-simultaneous excitation with 248 nm and 308 nm of 3-pentanone that is used as a fluorescence(More)
A conventional membrane-type stainless steel shock tube has been coupled to a high-repetition-rate time-of-flight mass spectrometer (HRR-TOF-MS) to be used to study complex reaction systems such as the formation of pollutants in combustion processes or formation of nanoparticles from metal containing organic compounds. Opposed to other TOF-MS shock tubes,(More)