| Autor: |
Balasubramanian, V., Jayaraman, G., Iyengar, S. R. K. |
| Předmět: |
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| Zdroj: |
ZAMM -- Journal of Applied Mathematics & Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik; May1999, Vol. 79 Issue 5, p335-352, 18p, 1 Diagram, 2 Charts, 14 Graphs |
| Abstrakt: |
The combined effect of secondary flows and irreversible boundary reaction on the dispersion process is analysed based on the generalized dispersion model proposed by Gill and Sankarasubramanian [3]. The study describes the development of dispersive transport following the injection of a tracer in terms of the three effective transport coefficients viz. the exchange, the convection, and the dispersion coefficients. Unlike the corresponding straight tube analysis (Sankarasubramanian and Gill [4], Phillips et al. [16]) where the exchange coefficient was found to be independent of the velocity distribution, the present analysis shows its dependence on cross stream velocity distribution (secondary flow effect). Second order corrections (in terms of the Dean number) for the asymptotic large time evaluations are also made for the convection and dispersion coefficients. In the absence of interface transport, the results are in agreement with Erdogan and Chatwin [21] with the exchange coefficient approaching zero and the other two coefficients attaining their proper values. At the other extreme, it is shown that for rapid wall reaction mechanism and in the presence of mild secondary flows, the exchange coefficient is enhanced, while the convection and the dispersion coefficients are reduced. For large values of the absorption parameter, the retention effects are found to be the rate determining processes and the secondary flows have negligible effect, thus confirming the earlier results in the case of secondary flows with absorbing curved walls (Jayaraman et al. [26]). [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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