- Author
-
Shuen, J. S.
|
Solomon, A. S. P.
|
Faeth, G. M.
- Title
- Structure of Dilute Combusting Sprays. Final Report.
- Coporate
- Pennsylvania State Univ., University Park
- Sponsor
- National Aeronautics and Space Administration, Washington, DC
- Report
-
NASA CR-174838
January 1985
122 p.
- Contract
- NAG-3-190
- Keywords
-
turbulent flames
- Abstract
- An experimental and theoretical study of drop processes in a turbulent flame is described. The experiments involved a monodisperse (105 and 180 um initial diameter) stream of methanol drops injected at the base of a turbulent methane-fueled diffusion flame burning in still air. The following measurements were made: mean and fluctuating phase velocities, mean drop number flux, drop-size distributions and mean gas-p[hase temperatures. Measurements were compared with predictions of two separated flow models: (1) deterministic separated flow, where drop-turbulence interactions are ignored; and (2) stochastic separated flow, where drop-turbulence interactions are considered using random-walk computations. The stochastic separated flow analysis yielded best agreement with measurements, since it provides for turbulent dispersion of drops which was important for present test conditions (and probably for most comsting sprays as well). Distinguishing the presence or absence of envelope flames around the drops, however, was relatively unimportant for present tests conditions, since the drops spent most of their lifetime in fuel-rich regions of the flow where this distinction is irrelevant.