Scattered-light scanner measurements of cryogenic liquid-jet breakup
Abstract
The effect of highly turbulent Mach 1 gas flow and high thermal gradients on drop size measurements was investigated with a scattered light scanner. The instrument, developed at NASA-Lewis, was used to measure characteristic drop diameters or cyrogenic liquid sprays. By correcting for gas turbulence and thermal gradient affects, it was possible to obtain good reproducible data with the scattered light scanner. Tests were conducted primarily in the aerodynamic-stripping regime of liquid atomization and it was found that the loss of small droplets due to vaporization and dispersion had a marketed effect on drop size measurements. The nitrogen gas flow rate exponent of 1.33 is the same as that predicted by atomization theory for liquid jet breakup in high velocity gas flow. However, when the sprays were sampled farther downstream of the atomizer, at axial distances of 2.5 and 4.5 cm, the exponent for W sub n decreased 1.2 and 0.9, respectively. This was attributed to the loss of small droplets due to vaporization when values of downstream axial distances exceeded 1.3 cm.
- Publication:
-
Presented at the 2nd International Congress Optical Particle Sizing
- Pub Date:
- 1990
- Bibcode:
- 1990ops..cong....5I
- Keywords:
-
- Cryogenic Fluids;
- Drop Size;
- Gas Flow;
- Liquid Atomization;
- Multiphase Flow;
- Temperature Gradients;
- Turbulence;
- Atomizing;
- Light Scattering;
- Particle Size Distribution;
- Transonic Speed;
- Vaporizing;
- Instrumentation and Photography