Accession Number : ADA304081
Title : Determination of Structure Temperature and Concentration in the Near Injector Region of Impinging Jets Using Holographic Techniques.
Descriptive Note : Final rept. 1 Jun 92-31 May 95,
Corporate Author : ILLINOIS UNIV AT URBANA MECHANICAL ENGINEERING LAB
Personal Author(s) : Poulikakos, Dimos
PDF Url : ADA304081
Report Date : JAN 1996
Pagination or Media Count : 113
Abstract : The purpose of this research was to investigate the dense region of a spray generated by two high speed impinging jets, using a novel holographic technique developed and tested under the present grant. The dense spray region was shown to contain a large population of non-spherical liquid elements. This region cannot be studied with more conventional optical methods. The structure of the liquid elements near the jet impact point was indicative of the mechanisms of the disintegration process. The effect of several parameters such as the impingement angle, the liquid jet velocity, the orifice diameter, and the liquid properties on the atomization process was investigated. In addition, experiments in a high temperature chamber were performed. The overall spray pattern clearly revealed the wave nature of the breakup process, which was more distinct with high viscosity liquids. Smaller and faster droplets were generated with larger impingement angle, higher jet velocity, and smaller orifice diameter. Surface tension plays an important role in the droplet size without any noticeable effect on the spray pattern, whereas viscosity affects the structure without any significant effect on the droplet size. In the parametric domain investigated, the average droplet velocities were linearly proportional to the liquid jet velocity despite the large variation in the liquid properties. The droplet velocities were not affected markedly by the liquid properties. The theoretical predictions for the mean droplet size provided a reasonable order-of-magnitude estimate. The superiority of the universal root-normal distribution to the Rosin-Rammier distribution was proved in the great majority of high jet velocity cases tested. For low jet impingement velocities, existing theoretical predictions on the size and shape of the liquid sheet as well as on the size distribution of the droplets
Descriptors : *COMBUSTION, *HOLOGRAPHY, *INJECTORS, *LIQUID ROCKET PROPELLANTS, *LIQUID JETS, VELOCITY, DIAMETERS, PARAMETRIC ANALYSIS, HIGH TEMPERATURE, DROPS, HIGH DENSITY, LIQUID PROPELLANT ROCKET ENGINES, FLUID DYNAMICS, VISCOSITY, JET FLOW, SPRAYS, SURFACE TENSION, IMPACT POINT, ORIFICES, GLYCEROLS, ATOMIZATION, HIGH VISCOSITY, IMPINGEMENT.
Subject Categories : Air Condition, Heating, Lighting & Ventilating
Combustion and Ignition
Liquid Rocket Propellants
Distribution Statement : APPROVED FOR PUBLIC RELEASE