The Heat Flux burner
In order to develop and validate numerical models and combustion reaction mechanisms it is essential to measure fundamental combustion properties accurately. Hence, combustion scientists have developed idealised systems over the years which are optimised to determine these. The heat flux burner is such a system which was developed at the TU Eindhoven for analysing laminar flames. This burner can stabilise flames which are:
- more or less adiabatic, which means no heat loss to the surroundings, and
- flat, which means that the flame can be assumed to be 1D.
Due to the laminar flat flame topology the heat flux burner is perfectly suitable for species concentration measurements and due to the configuration the adiabatic laminar burning velocity can be measured accurately. Both give essential experimental data for developing and validating combustion reaction mechanisms. Besides that, accurate data of the laminar burning velocity becomes important in the trade-off between combustion stability and pollutant emissions.
The heat flux burner is optimized in such a way that phenomena like flame stretch and heat loss of the flame can be neglected. This has a positive effect on the accuracy of the laminar burning velocity measurements when using the heat flux method. Furthermore, a direct comparison between experimental data and both theoretical and detailed numerical studies of laminar burning velocities is possible and no correction of the before mentioned phenomena have to performed. Additionally, the laminar burning velocity is determined with the heat flux method by interpolation instead of extrapolation which leads to an additional increase of the accuracy of the heat flux method compared to other methods.
In short, the burner setup which is used to determine the adiabatic burning velocity, is build up using the following parts:
- The burner (can be delivered by the TU/e, for more information you can contact dr. Liselotte Vogels-Verhoeven at email@example.com)
- Water bath
- Hot (85 degrees Celsius)
- Cold (25 degrees Celsius)
- Gas flow (fuel & air) – Mass Flow Controllers to control the gas supplies
- Module to read out thermocouples
- Computer + thermocouple sofware
For more detailed information related to the burner configuration one is referred to the PhD thesis of K.J. Bosschaart “Analysis of the Heat Flux Method for Measuring Burning Velocities”. ISBN 90-386-2744-0 Available at: http://alexandria.tue.nl/extra2/200513271.pdf