The Modeling of Drop-Containing Turbulent Eddies
Abstract
Formulae are presented for spherical clusters of evaporating drops in axial flows and cylindrical clusters of evaporating drops in vortical flows. In both situations the formula is valid for dense and dilute clusters of drops. It is shown that evaporation of dense, spherical clusters of drops is substantially influenced by turbulence. Dense clusters of drops embedded in low turbulence surroundings initially contract due to evaporative cooling; modest expansion follows due to hot gas eventually entering the cluster. Dense clusters of drops embedded in high turbulence surroundings experience a short initial period of evaporative cooling which is followed by substantial cluster expansion. In contrast, the evaporation of dilute clusters of drops is not sensitive to turbulence; minimal cooling of the gas results in a minimal contraction with no expansion to follow. The evaporation time of the dense, cylindrical clusters of drops in vortical flows is mainly controlled by the initial solid body rotation of the drops. Evaporation time is a strong decreasing function of the air/fuel mass ratio in the dense cluster regime and asymptotically levels off in the dilute cluster regime. As the drops evaporate they move out radially forming a cylindrical shell around the center of the vortex. Both the final to initial volume ratio and the final to initial shell thickness ratio are decreasing functions of the initial air/fuel mass ratio. Dense fuel sprays.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1989
- Accession Number
- ADA221050
Entities
People
- A. Léonard
- Josette Bellan
- Stephen Wiggins
- V. Rom-kedar
Organizations
- California Institute of Technology