An explicit algebraic closure for passive scalar-flux: Applications in channel flows at a wide range of reynolds numbers
Journal
Journal of Marine Science and Engineering
Date Issued
November 2020
DOI
10.3390/jmse8110916
Abstract
In this paper, we propose an algebraic model for turbulent scalar-flux vector that stems from tensor representation theory. The resulting closure contains direct dependence on mean velocity gradients and quadratic products of the Reynolds stress tensor. Model coefficients are determined from Direct Numerical Simulations (DNS) data of homogeneous shear flows subjected to arbitrary mean scalar gradient orientations, while a correction function was applied at one model coefficient based on a turbulent channel flow case. Model performance is evaluated in Poiseuille and Couette flows at several Reynolds numbers for Pr = 0.7, along with a case at a higher Prandtl number (Pr = 7.0) that typically occurs in water–boundary interaction applications. Overall, the proposed model provides promising results for wide near-wall interaction applications. To put the performance of the proposed model into context, we compare with Younis algebraic model, which is known to provide reasonable predictions for several engineering flows.
File(s)![Thumbnail Image]()
Name
jmse-08-00916.pdf
Size
2.01 MB
Format
Adobe PDF
Checksum (MD5)
7fdfebfc0e7ec9f04375d95e00c07310