TY - JOUR
T1 - Clipping over Dissipation in Turbulence Models
AU - Kean , Kiera
AU - Layton , William
AU - Schneier , Michael
JO - International Journal of Numerical Analysis and Modeling
VL - 2-3
SP - 424
EP - 438
PY - 2022
DA - 2022/04
SN - 19
DO - http://doi.org/
UR - https://global-sci.org/intro/article_detail/ijnam/20489.html
KW - Energy dissipation rate, turbulence.
AB - <p style="text-align: justify;">Clipping refers to adding 1 line of code $A ⇐ {\rm min}\{A, B\}$ to force the variable $A$ to stay below a present bound $B.$ Phenomenological clipping also occurs in turbulence models
to correct for over dissipation caused by the action of eddy viscosity terms in regions of small
scales. Herein we analyze eddy viscosity model energy dissipation rates with 2 phenomenological
clipping strategies. Since the true Reynolds stresses are $O(d^2)$ ($d$ = wall normal distance) in
the near wall region, the first is to force this near wall behavior in the eddy viscosity by $ν_{turb}⇐ {\rm min}\{ν_{turb}, \frac{\kappa}{T_{ref}}d^2\}$ for some preset $\kappa$ and time scale $T_{ref}.$ The second is Escudier’s early proposal
to clip the turbulence length scale in a common specification of $ν_{turb},$ reducing too large values
in the interior of the flow. Analyzing respectively shear flow turbulence and turbulence in a box
(i.e., periodic boundary conditions), we show that both clipping strategies do prevent aggregate
over dissipation of model solutions.</p>