fluid tangential stabilization¶
Module: fluid
Category: load
Type string: "fluid tangential stabilization"
Parameters¶
| Name | Description | Default | Units |
|---|---|---|---|
beta |
beta | 1 | [] |
Description¶
In a fluid or fluid-FSI analysis, this boundary condition prescribes the tangential component of the viscous traction, \(\mathbf{t}_{t}^{\tau}=\left(\mathbf{I}-\mathbf{n}\otimes\mathbf{n}\right)\cdot\mathbf{t}^{\tau}\), such that it opposes the tangential fluid flow \(\mathbf{v}_{t}=\left(\mathbf{I}-\mathbf{n}\otimes\mathbf{n}\right)\cdot\mathbf{v}\) on the selected boundary surface, with \(\mathbf{n}\) representing the outward normal to this surface. Specifically, \(\mathbf{t}_{t}^{\tau}=-\beta\rho_{r}\left|\mathbf{v}_{t}\right|\mathbf{v}_{t}\), where \(\beta\) is a unitless user-defined parameter (typical values may range from 0 to 1) and \(\rho_{r}\) is the referential fluid density.
<surface_load type="fluid tangential stabilization" surface="surface1">
<beta lc="1">1</beta>
</surface_load>