Fuel spray vaporization is a crucial phase in the operation of liquid fuel combustion devices. At present there is a lack of studies of evaporating sprays with quantitative measurements of the vapor phase distribution, a result of the limitations of the measurement techniques available for measuring vapor. A nonintrusive, laser based, infrared extinction technique has been developed based on the strong absorption of incident radiation at a 3.39 wavelength by hydrocarbon fuels. The technique holds great promise for accurate quantitative measurement of the vapor phase but, due to its limited use, little knowledge is available on the accuracy of the technique in two-phase flows. In order to fully assess the accuracy and limitations of the infrared extinction technique in quantifying fuel vaporization, an experiment is proposed in which the techniques will be used in a very controlled simulated spray environment. The simulated spray consists of solid polystyrene spheres injected with a pure hydrocarbon gas, providing great flexibility in studying the effects of spray characteristics on the accuracy of the vapor measurements. Finally, improvements are proposed in the optical system geometry previously used for the infrared extinction technique, allowing more spatially precise measurements. Spatial precision is vital to the successful application of the infrared extinction technique to pulsed sprays and highly turbulent flows.
