Effects of temporally varying liquid-phase mass diffusivity in multicomponent droplet gasification

Journal Article · Sun Jun 15 04:00:00 EDT 2008 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2007.12.007· OSTI ID:21044864

Zhang, Huiqiang ^[1]; Law, Chung K ^[1]

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1. Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

The relative roles of liquid-phase diffusional resistance and volatility differential in multicomponent droplet gasification are revisited, recognizing that liquid-phase mass diffusivities can be substantially increased as the droplet is progressively heated upon initiation of gasification, leading to a corresponding substantial weakening of the diffusional resistance. Calculations performed using realistic and temperature-dependent thermal and mass diffusivities indeed substantiate this influence. In particular, the calculated results agree with the literature experimental data, indicating that the gasification mechanism of multicomponent fuels is intermediate between diffusion and distillation limits. Investigation was also performed on gasification at elevated pressures, recognizing that the liquid boiling point and hence the attainable droplet temperature would increase with increasing pressure, causing further weakening of the liquid-phase diffusional resistance. This possibility was again verified through calculated results, suggesting further departure from diffusion limit toward distillation limit behavior for gasification at high pressures. The study also found that diffusional resistance is stronger for the lighter, gasoline-like fuels as compared to the heavier, diesel-like fuels because the former have overall lower boiling points, lower attainable droplet temperatures, and hence lower mass diffusivities in spite of their lower molecular weights. (author)

• OSTI ID: 21044864
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 4 Vol. 153; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
DIESEL FUELS
DIFFUSION
DROPLETS
GASIFICATION
GASOLINE
LIQUIDS
Liquid mass diffusivity
MASS
Multicomponent droplets
PRESSURE DEPENDENCE
PRESSURE RANGE KILO PA
PRESSURE RANGE MEGA PA 01-10
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
VOLATILITY