Accession Number : ADA301873

Title :   Droplet Collision in Liquid Propellant Combustion.

Descriptive Note : Final technical rept. 1 Jun 92-31 May 95,

Corporate Author : PRINCETON UNIV NJ DEPT OF MECHANICAL AND AEROSPACE ENGINEERING

Personal Author(s) : Law, C. K.

PDF Url : ADA301873

Report Date : 25 OCT 1995

Pagination or Media Count : 10

Abstract : Droplet collision is of relevance to spray combustion, intimately influencing the spray characteristics in the dense spray region. The present study aims to gain fundamental understanding on the mechanisms governing the observed phenomena of permanent coalescence, bouncing, and separation upon droplet collision. Specific issues of interest include the extent of droplet deformation, the dynamics of the inter-droplet flow, the relative importance of the gas resistance force as compared to the collision inertia, and the relevant rheological properties of the gases and liquids. Extensive experiments have been performed for various liquids, environment gases, and system pressures. A unified concept has crystallized regarding the specific mechanisms and factors controlling the five distinct regimes of collision outcomes for both water and hydrocarbon droplets, namely (I) coalescence with slight deformation, (II) bouncing, (III) coalescence with substantial deformation, (IV) coalescence followed by separation for near head-on collisions, and (V) coalescence followed by separation for off-center collisions. A coalescence/separation criterion defining the transition between regimes (III) and (IV) for head-on collisions was also derived and found to agree well with the experimental data. jg p.2

Descriptors :   *COMBUSTION, *COALESCENCE, *DROPS, *LIQUID PROPELLANTS, *SPRAYS, EXPERIMENTAL DATA, INERTIA, ENVIRONMENTS, DYNAMICS, WATER, RESISTANCE, DEFORMATION, GASES, HYDROCARBONS, HIGH DENSITY, PRESSURE, RHEOLOGY, SEPARATION, COLLISIONS, HEAD ON ORIENTATION.

Subject Categories : Combustion and Ignition
      Physical Chemistry
      Fluid Mechanics
      Liquid Rocket Propellants

Distribution Statement : APPROVED FOR PUBLIC RELEASE