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Sample data

Target flames

Burner Configurations

McKenna Burner
Gülder Burner
Santoro Burner

Sample data

Joint measurements and sample data evaluation for the LII workshop 2005 in Duisburg

Sample data

On the workshop in Duisburg we would also like to compare the different models that are frequently used for LII data analysis. Therefore, we provide three data sets of time-resolved LII measurements performed under different conditions. Both, the temporal and spatial laser profile is provided and also the calibration factors for the two-color experiments. The initial temperature of the soot particles after the laser pulse can be analyzed in the way everybody feels most comfortable with.

Each of the files represents a set of two-color data of raw LII signals in excel file format. The files can be downloaded from the website at http://www.vug.uni-duisburg.de/ivg/lii-measurement.html. There are four worksheets in each file. The first two represent the raw data for detection channels 1 and 2, the third is a plot of this data, and the fourth provides the modelling parameters. These parameters include the spatial and temporal profiles of the laser beam, as well as the calibration values for each channel. Note that all of these parameters are different for each data set.

The following should also be noted:

  • The excitation wavelength for all provided data sets was 532 nm, generated with a frequency-doubled Nd:YAG laser.
  • Each file provides two channel data for one experiment. The header information gives a time offset and time step which will allow you to map out the measured voltage signal. By applying the correct calibration factor one can map out the absolute intensity of each channel. The time base is relative to the Q-switch sync signal. There is no direct correlation between the absolute time base of the LII data and the absolute time base of the temporal profile of the laser pulse.
  • The laser was not injection seeded
  • All the data presented are multipulse averages
  • Jitter is < 1 ns
  • Time response of the LII signal photomultipliers is 1.8 ns
  • A photodiode detector was used to characterize the temporal profile of the laser, with a 1 ns rise time and digitized at 8 bits resolution
  • Regarding the filter function for the detection, they are typical multi-cavity interference filters that can be reasonably approximated with a square profile. Of course, this introduces an error, but all models being compared will then have the same error
  • The calibration is the absolute sensitivity of the detection system (lenses, filters, photomultipliers) and is calibrated with an irradiance source at the probe volume location.

For fairness in the analysis of the data we do not provide more information about the type of flame in which the experiments have been performed.

  • Cond_A.xls, is a mid-level fluence experiment (0.50 mJ/mm2). The soot did not reach sublimation temperatures. The ambient temperature was estimated to be approximately 1750 K.
  • Cond_B.xls, is a higher-level fluence experiment (0.75 mJ/mm2). The soot reached sublimation temperatures. The ambient temperature was estimated to be approximately 1750 K.
  • Cond_C.xls is a mid-level fluence experiment (0.8 mJ/mm2). The soot did not reach sublimation temperatures. The ambient temperature was estimated to be approximately 575 K.
  • NEW: Correction Channel 2.xls Correction for the Channel 2 values.

Everybody is kindly invited to apply his own model for data evaluation. If you have typically use models of different degrees of refinement we would like to encourage you to use all of them. During the meeting in Duisburg we will compare the results which have been calculated with the different models. Additional comparison will be provided with independent measurements. This is an excellent chance for you to test your approach in different measurement situations that might be inaccessible to you usually. For the LII community this is an excellent opportunity to locate typical problems or problematic measurement conditions.

Letzte Änderung: 20. September 2005
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