Pressure Scaling Laws for Spectroscopic Quantification of Nitric Oxide (NO) in Combustors

In Phase I, LGR and Stanford University (R.K. Hanson's group, High Temperature Gasdynamics Laboratory, Mechanical Engineering Department) will develop and demonstrate a laser induced fluorescence spectroscopic technique for accurate and spatially precise measurements of NO in high-performance combustors operating over a range of pressures (0.5-60 atm). The LIF diagnostic strategy will provide NO measurements with high species selectivity, measurement accuracy and sensitivity (1 ppm), spatial resolution (<250 microns) and temporal resolution (1 microsecond) through careful selection of laser excitation wavelength combined with wavelength-resolved fluorescence collection. An automated computer-based data collection and analysis system will yield real-time NO measurements that will allow combustion researchers and engine designers with fast, reliable feedback. The system will be applied in Stanford's high pressure combustion facility to determine pressure scaling laws that will enable accurate modeling of NO formation processes in realistic combustors for a wide range of pressures. In Phase II, LGR and SU will construct, deploy and test an advanced prototype instrument for NO measurements in realistic high-pressure liquid-fueled combustors. LGR and SU will demonstrate the instrument's reliability, performance and capability to report in real-time NO measurements in an Air Force combustion facility, and deliver an instrument hardened for realistic engine environments.