Laser Diagnostics in Jets and Flames.

An integrated four component pulsed vibrational Raman scattering-one dimensional Laser Doppler Velocimeter scattering measurement system is applied to non-reacting and reacting free jet flows. Simultaneous, instantaneous, non-intrusive, remote, and at a point measurements of velocity, temperature and specie concentration--mean value, turbulent intensity and histogram distributions are shown. In addition, specie concentration second and third order scalar cross -correlation distributions are presented as a measure of specie mixing or "unmixedness". It is found that many experimental parameters needed for theoretical flow modeling can be obtained by this measurement system. A highly implicit numerical code was written and applied to model the non-reacting turbulent jet flow. Good agreement is shown between the numerical results and experimental measurements. The code is extended to model a premixed methane-air reacting free jet flow using a one-step global "laminar" Arrhenius rate chemical source term. It is found that agreement existed between the numerical solution and experimental measurements, but that refinements to the turbulent model and the use of a "turbulent" chemical source term are required to obtain better agreement.