Stable stratification effects on the flow past surface obstructions: A numerical study (EN)

Bergeles, GC (EN)

Trifonopoulos, DA (EN)

Numerical predictions of the stably stratified flow fields past surface-mounted obstructions are presented. The time-averaged Reynolds equations, coupled with the continuity and temperature/concentration equation for the incompressible fluid, have been solved in the transformed space, using finite differences, adopting the Boussinesq approximation to account for density variations. Buoyancy effects on turbulence have been considered in the two-equation k-ε model, which has been used as a turbulence closure. The turbulent flow fields over a two-dimensional fence and around a three-dimensional hill were simulated for neutral and various stable conditions. The decrease of the cavity wake length behind the two-dimensional fence, due to the temperature gradient, was clearly depicted by the computations. The stability effect on the mean flow past the three-dimensional axisymmetric hill, for various Froude numbers, were reproduced satisfactorily, although some underestimation of the bouyancy influences in some cases was observed. The boundary layer lee side separation was suppressed with increasing stability, and the beginning of a hydraulic jump was predicted for Froude numbers smaller than unit. The comparison between the computations and the available measurements established the reliability of the presented method. © 1992. (EN)

journalArticle (EN)

Stable Stratification (EN)

Flow Over Three Dimensional Hill (EN)

flow over three-dimensional hill (EN)

Finite Difference Method (EN)

turbulence modeling (EN)

stable stratification (EN)

finite differences (EN)

Engineering, Mechanical (EN)

Thermodynamics (EN)

Turbulent Flow (EN)

Approximation Theory (EN)

Boussinesq approximation (EN)

Mechanics (EN)

Surface Obstructions (EN)

Boussinesq Approximation (EN)

Boundary Layer Flow (EN)

Mathematical Models (EN)

National Technical University of Athens

Digital Library of National Technical University of Athens | Dspace@NTUA

Κεντρική Βιβλιοθήκη Ε.Μ.Π.

Ιδρυματικό Αποθετήριο

Δημοσιεύσεις μελών Δ.Ε.Π. σε περιοδικά

International Journal of Heat and Fluid Flow (EN)

English

1992 (EN)

http://hdl.handle.net/123456789/10817

0142-727X (EN)

13 (EN)

2 (EN)

159 (EN)

10.1016/0142-727X(92)90022-2 (EN)

151 (EN)

ISI:A1992HZ82100006 (EN)

BUTTERWORTH-HEINEMANN (EN)