Two-dimensional Raman mole-fraction and temperature measurements for hydrogen-nitrogen mixture analysis.

A two-dimensional laser Raman technique was developed and applied to directly probe the population number of selected rotational and vibrational energy levels of hydrogen and nitrogen. Using three cameras simultaneously, temperature and mole fraction images could be detected. Three different combinations of rotational and vibrational Raman signals of hydrogen and nitrogen were analyzed to identify the combination that is most suitable for future mixture analysis in hydrogen internal combustion engines. Here the experiments were conducted in an injection chamber where hot hydrogen was injected into room temperature nitrogen at 1.1 MPa.