Measurement of the coefficient of transverse dispersion in flow through packed beds for a wide range of values of the schmidt number

• Tipo: Artigo em Revista Científica Internacional
• Data: 2001

Autores

J. M. P. Q. Delgado (Autor) FEUP; J. R. F. Guedes de Carvalho (Autor) FEUP

Revista

Título: Transport in Porous Media

Vol. 44 Nº 1

Páginas: 165-180

ISSN: 0169-3913

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 20 Citações

ISI Web of Science

Scopus - 21 Citações

COMPENDEX

Outras Informações

ID Authenticus: P-000-V5E

DOI: 10.1023/A:1010769402206

Abstract (EN): Experimental values of the coefficient of transverse dispersion (DT) were measured with the system 2-naphthol/water, over a range of temperatures between 293 K and 373 K, which corresponds to a range of values of viscosity (µ) between 2.83 × 10¿4 Ns/m2 and 1.01 × 10¿3 Ns/m2 and of molecular diffusion coefficient (Dm) between 1.03×10¿9 m2/s and 5.49×10¿9 m2/s. Since the density (¿) of water is close to 103 kg/m3, the corresponding variation of the Schmidt number (Sc= µ/¿Dm) was in the range 1000 ¿ 50. More than 200 experimental values of the transverse dispersion coefficient were obtained using beds of silica sand with average particle sizes (d) of 0.297 and 0.496 mm, operated over a range of interstitial liquid velocities (u) between 0.1 mm/s and 14 mm/s and this gave a variation of the Reynolds number (Re= ¿du¿/µ) between 0.01 and 3.5. Plots of the dimensionless coefficient of transverse dispersion (DT/Dm) vs. the Peclet number (Pem = ud/Dm) based on molecular diffusion bring into evidence the influence of Sc on transverse dispersion. As the temperature is increased, the value of Sc decreases and the values of DT/Dm gradually approach the line corresponding to `gas behaviour¿ (i.e. Sc ¿ 1), which is known to be well approximated by the equation DT/Dm = 1/¿ + ud/12Dm, where ¿ is the tortuosity with regard to diffusion

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 16