Acetone laser induced fluorescence for low pressure/low temperature flow visualization

Acetone fluorescence provides a useful way to visualize the fluid mixing process within supersonic wind tunnels, some of which operate in the low temperature (240-300 K) and low pressure range (0.1-1 atm). Measurements are presented to quantify the dependence of the acetone laser induced fluorescence (LIF) signal on temperature and pressure in this range. The temperature and pressure sensitivity of the acetone LIF signal resulted in less than an 8% variation over the experimental conditions for a laser excitation wavelength of 266 nm. Condensation of the acetone vapor was identified as a potential problem for this diagnostic technique. Methods to prevent and check for condensation are discussed.