Measurements of the Reaction between NO and O3 in a Jet Stream of NO Dilute Gas by LIF Methods.

Abstract

An experimental study on an effect of jet exhaust gas in a simulated ozone layer was conducted. A stratospheric condition was simulated in use of a vacuum chamber, where its pressure was sustained 2.67 kPa, this being equal to the one at the altitude 25 km. NO gas, which was diluted by N2, was fired from a nozzle as an exhaust gas in the simulated ozone layer. NO and NO2 concentration in jet streams were measured by LIF methods, and then reaction amounts between NO and O3 were derived from these LIF images. The reaction rate derived from NO-LIF was much bigger than the actual one, because O3 absorbed laser beam near about 226.1 nm to simulate NO molecular and NO-LIF signal. It was not proper to use NO-LIF method to determine the reaction amount between NO and O3. However, it was useful to visualize the flow in this condition because of its strong intensity. The reaction amount derived from NO2-LIF was valid compared with a result of simple calculations. NO2-LIF should be used to measure the reaction rate qualitatively between NO and O3 in the simulated ozone layer.