Author(s): Maria Tsakiri; Panayotis Prinos
Linked Author(s): Panagiotis Prinos
Keywords: Drag resistance; Exchange flow; Heat transfer; Natural convection; Vegetation
Abstract: In the present study, thermally driven exchange flow between open water and rigid emergent vegetation, due to different radiation absorption, is investigated numerically. The unsteady Navier–Stokes equations and the energy equation are solved with the Fluent CFD code. The effect of vegetation is taken into account through additional terms, which are based on the porous media theory, in the momentum equations and the absorption of radiation through additional term in the energy equation. These terms are included in the model through User Defined Functions. The Boussinesq model is used for taking into account the density difference due to temperature difference. Three cases with different vegetation porosity are examined (n=0. 97, 0. 92, 0. 85) and one case without vegetation for comparison purposes. Numerical results for the velocities and the heights of the currents as well as for the temperature differences are presented and are compared with available experimental data. The velocity of the current is found to be almost constant and it decreases with decreasing vegetation porosity.
Year: 2015