The fluid elements support pressure loads at the nodal PRES degrees of freedom and velocity body loads (FLUE) at the node or element as shown in Table 3.1: Load Options for Thin Film Fluid Elements. Pressure loads are applied using the D family of commands. The velocity load is applied using the BF family of commands. For the velocity load, a positive velocity load will cause a positive pressure. For a harmonic analysis, a positive velocity load will cause a positive in-phase pressure load. See Applying Body Loads for details on applying body loads.
Note: Velocity body loads (FLUE) are the velocities of the moving wall in a direction normal to the wall. They are not in-plane velocities of the fluid.
Table 3.1: Load Options for Thin Film Fluid Elements
| Load | Type | Mechanical APDL Label |
|---|---|---|
| Pressure | Nodal DOF | PRES |
| Normal Velocity | Body Load | FLUE |
The recommended equation solvers for the fluid elements are the Sparse Direct Solver (SPARSE), the Jacobi Conjugate Gradient Solver (JCG) and the Incomplete Cholesky Conjugate Gradient Solver (ICCG).