Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

SIMILARITIES BETWEEN HEAT AND MASS TRANSFER ENHANCEMENT IN CONVECTIVE FLOW, USING VARIATIONAL OPTIMIZATION TECHNIQUE

Get access (open in a dialog) DOI: 10.1615/IHTC16.cov.021341
pages 2715-2722

Abstrakt

In convective flow transfer processes, variational techniques can be used in order to find theoretical optima and determine velocity and scalar fields that will minimize an objective functional directly linked with the entropy generation rate in a channel under a viscous dissipation constraint. In order to point out and to analyze the general significance of this approach, the calculus of variation is applied to forced convective flow thermodynamic optimization by considering heat transfer enhancement on the one hand and mass transfer enhancement on the other hand. This comparison addresses the mathematical expressions derived from the calculus of variation and the numerical simulations of optimized flows in order to assess their efficiency in reducing total entropy generation and in optimizing the convective transfer. A parametric study analyzes the influence of key parameters like flow inlet velocity, heat flux density, mass flux density of the minority chemical species and weighting factors in the objective functional. Results show that this variational approach can suggest optimized velocity and scalar fields in different contexts where viscous friction and diffusion processes take place. The parametric study reveals a discontinuity point where temperature, mass fraction and velocity fields jump between two perturbation levels when compared with the case where no optimization is applied at all.