000004615 001__ 4615
000004615 005__ 20141119144538.0
000004615 04107 $$aeng
000004615 046__ $$k2002-06-02
000004615 100__ $$aHuang, Wenrui
000004615 24500 $$aSENSITIVITY STUDY OF A 2nd ORDER TURBULENCE MODEL IN A STRATIFIED TIDAL RIVER

000004615 24630 $$n15.$$pProceedings of the 15th ASCE Engineering Mechanics Division Conference
000004615 260__ $$bColumbia University in the City of New York
000004615 506__ $$arestricted
000004615 520__ $$2eng$$aEddy viscosity calculated from the turbulent model has significant effects on vertical stratification. In this study, a three dimensional hydrodynamic model was applied to a strongly stratified tidal river. The model employed a 2nd order turbulent model (Mellor and Yamada, 1982) that has been widely used in the applications to large-scale geophysical flows. Field observations salinity and velocity at surface and bottom stations in Apalachicola River show strong stratification dependent to the river flow and tidal conditions. Using the default turbulent model parameters model predictions overestimate current and salinity stratification. In order to improve the performance of the turbulent model, a correction factor of eddy viscosity was proposed to allow the slight adjustment of the turbulent eddy viscosity that is very sensitive to the calculation of the vertical stratification. Sensitivity study was conducted determine the optimal correction factor within the range between 1.0 to 1.2. For the case study in Apalachicola River, results show that the increase of the turbulent eddy viscosity to a 1.12 factor results in the best agreement between model predictions and observations. The result from this study also shows that the default parameters in some second order turbulent model may not be universal to all situations. Using the proposed correction factor of the eddy viscosity will provide a useful approach for modelers to turbulent model performance in predicting turbulent mixing in the stratified flow.

000004615 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000004615 653__ $$aTurbulent model, stratified flow.

000004615 7112_ $$a15th ASCE Engineering Mechanics Division Conference$$cNew York (US)$$d2002-06-02 / 2002-06-05$$gEM2002
000004615 720__ $$aHuang, Wenrui
000004615 8560_ $$ffischerc@itam.cas.cz
000004615 8564_ $$s72670$$uhttps://invenio.itam.cas.cz/record/4615/files/057.pdf$$yOriginal version of the author's contribution as presented on CD, .
000004615 962__ $$r4594
000004615 980__ $$aPAPER