Abstract
We have developed a two-dimensional Raman technique which provides the hydrogen mole fraction and the hydrogen temperature by directly probing the hydrogen and the nitrogen molecular number densities and the temperature sensitive population distribution of the hydrogen molecules in different rotational and vibrational molecular energy levels. In addition to the benefit that no tracers are needed, this measurement technique profits from a simple experimental setup and a straight forward data evaluation procedure with a prior non-extensive calibration. To develop this 2-D Raman technique for simultaneous mole fraction and temperature analysis inside a field of 20 × 23 mm with a local resolution of 200 μm and a temporal resolution of a few nanoseconds, hydrogen was injected with a temperature of 473 K into pressurized nitrogen with a temperature of 297 K at 1.1 MPa absolute pressure. Different measurement strategies acquiring different combinations of Raman rotational signals and Raman vibrational signals were elaborated to find the most suitable combinations for different conditions.
