Numerical modeling of buoyant ethanol-air wick diffusion flames
โ Scribed by H.-Y. Lyu; L.-D. Chen
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 874 KB
- Volume
- 87
- Category
- Article
- ISSN
- 0010-2180
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โฆ Synopsis
A numerical model based on a conserved-scalar approach is presented for buoyant ethanol-air wick diffusion flames at atmospheric and subatmospheric conditions. The model incorporates an equation that describes the interface condition of wick combustion. The prediction yields similarity solutions for flat-plate ethanol-air wick diffusion flames, but not for cylindrical wick diffusion flames. The fiat-plate solution yields a mass burning rate per unit surface area following the x-i/4 dependence of the classical similarity solution, where x is the streamwise distance. A pressure dependence of p0.644 is predicted for the flat-plate overall mass burning rate, in agreement with the p2/3 dependence reported in the literature. The cylindrical wicks have a mass burning rate per unit surface area that deviates from the x-i/4 dependence. The predicted mass burning rate, however, does not substantially deviate from the fiat-plate solution for cylinders with a moderate aspect ratio (of the order one). The deviation in mass burning rate is most pronounced when needle-like cylinders are considered. The variable-property effects are also examined. The results show that the Chapman gas and constant-Prandtl-number assumptions are not adequate for wick diffusion flames, even at the subatmospheric-pressure condition studied.
๐ SIMILAR VOLUMES
Flame-balls are stationary spherical premixed flames observed in certain near-limit mixtures. It is believed that radiative heat losses are an important stabilizing influence. Numerical solutions of flame balls are constructed for hydrogen-air mixtures using an accurate description of the chemical k