Molecular tagging manometry for gas phase flows: A feasibility study

The primary objective of the research conducted was to determine the feasibility of a proposed planar whole-field, non-intrusive, molecular based optical diagnostic technique to measure pressure in the body of gas flows; a capability that has so far remained elusive. The technique relied on the quenching of a molecular tracer's phosphorescence lifetime. The tracer used was acetone and the specific quenching mechanism relied on was oxygen quenching and acetone's self-quenching. A combined photochemistry and detection parameter based mathematical model was developed and was used to obtain optimal experimental conditions in order to detect a change in acetone's phosphorescence lifetime with change in pressure. An experimental set-up was built and measurements were made to obtain the required 'proof-of-concept'. The results obtained showed that the proposed technique is feasible and worth pursuing. The agreement of the experimental data with the model's predictions was within 10-12%.