Modelling the Transit Time of a Fast Response Flame Ionisation Detector During In-Cylinder Sampling

Fast Response Flame Ionisation Detectors can be used to observe events within the combustion chamber of engines to help understand the processes by which hydrocarbons escape combustion. In order to understand the timing of events it is necessary to establish the transit time of the measuring system, in particular the times associated with gas transport through the sampling capillaries. To this end, a quasi steady state flow model has been developed to evaluate the transit time for all parts of the cycle. These predictions can deviate significantly from those using steady-state assumptions.

Experimental validation is presented.