Modeling of fuel vapor jet eruption induced by local droplet heating

Sim, Jaeheon; Im, Hong G.; Chung, Suk Ho

Modeling of fuel vapor jet eruption induced by local droplet heating

Type

Conference Paper

Authors

Sim, Jaeheon

Im, Hong G.

Chung, Suk Ho

KAUST Department

Clean Combustion Research Center
Combustion and Laser Diagnostics Laboratory
Computational Reacting Flow Laboratory (CRFL)
Mechanical Engineering Program
Physical Science and Engineering (PSE) Division

Online Publication Date

2014-01-10

Print Publication Date

2014-01-13

Date

2014-01-10

Abstract

The evaporation of a droplet by non-uniform heating is numerically investigated in order to understand the mechanism of the fuel-vapor jet eruption observed in the flame spread of a droplet array under microgravity condition. The phenomenon was believed to be mainly responsible for the enhanced flame spread rate through a droplet cloud at microgravity conditions. A modified Eulerian-Lagrangian method with a local phase change model is utilized to describe the interfacial dynamics between liquid droplet and surrounding air. It is found that the localized heating creates a temperature gradient along the droplet surface, induces the corresponding surface tension gradient, and thus develops an inner flow circulation commonly referred to as the Marangoni convection. Furthermore, the effect also produces a strong shear flow around the droplet surface, thereby pushing the fuel vapor toward the wake region of the droplet to form a vapor jet eruption. A parametric study clearly demonstrated that at realistic droplet combustion conditions the Marangoni effect is indeed responsible for the observed phenomena, in contrast to the results based on constant surface tension approximation

Citation

Sim, J., Im, H. G., & Chung, S. H. (2014). Modeling of Fuel Vapor Jet Eruption Induced by Local Droplet Heating. 52nd Aerospace Sciences Meeting. doi:10.2514/6.2014-1017