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The heat transfer characteristics of a mesoscale continuous oscillatory flow crystalliser with smooth periodic constrictions

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journal contribution
posted on 15.03.2018 by Iyke Onyemelukwe, Brahim Benyahia, Nuno M. Reis, Zoltan Nagy, Chris Rielly
The heat transfer performance of a 5 mm internal diameter (I.D.) mesoscale continuous oscillatory flow crystalliser with smooth periodic constrictions (herein called SPC meso-tube) is herein reported for the first time for both steady flow and unsteady oscillatory flow conditions. Experimental values of the tube-side Nusselt number, 𝑁𝑒𝑑, accompanied by an estimability analysis, emphasized the key role played by smooth constrictions and bulk flow velocity in controlling tube-side heat transfer in the SPC meso-tube, while revealing a weaker influence of oscillatory flow on heat transfer enhancement in the tube. Although the presence of smooth constrictions provided an increased surface area to volume (SAV) ratio, and recirculation zones which promoted heat transfer rates, a maximum 1.7-fold heat transfer augmentation was obtained when fluid oscillations were combined with smooth constrictions. The behaviour of the SPC meso-tube was such that increasing the net flow Reynolds number, 𝑅𝑒𝑛, from 11 up to 54 with the combination of smooth constrictions and oscillatory flow resulted in the attainment of higher rates of heat transfer up to a maximum 𝑁𝑒𝑑 of 3.09. The Strouhal number, 𝑆𝑑, was also found to have a more significant effect on the heat transfer performance than oscillatory frequency, 𝑓. An empirical correlation was for the first time developed to describe the heat transfer characteristics of the SPC meso-tube, and predict 𝑁𝑒𝑑 based on experimental data for the range of net flow and oscillatory flow conditions investigated. A parameter estimability approach was also implemented to enhance the prediction capability of the correlation. The approach was based on a sequential orthogonalisation, thanks to which the most influential factors affecting the tube-side heat transfer were identified given the available experimental data. Overall, the results accentuate the efficient heat transfer capabilities of the SPC meso-tube in low laminar flow regimes, and its suitability for performing cooling crystallisations where tight temperature control of supersaturation is essential.

Funding

This work was supported by the EPSRC (EP/I033459/1) Centre for Innovative Manufacturing in Continuous Manufacturing and Crystallisation (CMAC) and the Doctoral Training Centre in Continuous Manufacturing and Crystallisation (EP/K503289/1).

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Chemical Engineering

Published in

International Journal of Heat and Mass Transfer

Citation

ONYEMELUKWE, I. ...et al., 2018. The heat transfer characteristics of a mesoscale continuous oscillatory flow crystalliser with smooth periodic constrictions. International Journal of Heat and Mass Transfer, 123, pp.1109-1119.

Publisher

Β© Elsevier

Version

AM (Accepted Manuscript)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Acceptance date

05/03/2018

Publication date

2018-03-27

Notes

This paper was published in the journal International Journal of Heat and Mass Transfer and the definitive published version is available at https://doi.org/10.1016/j.ijheatmasstransfer.2018.03.015.

ISSN

0017-9310

Language

en

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