a) Velocity Field [lines]
b) Fixed Velocity [lines]
c) Pressure Field [lines]
This condition is used to impose the velocity on a line equal to its value given in the corresponding Material (Fluid) window (fields VelX_Field, VelY_Field and VelZ_Field).
Any of the
above fields can be a
It is also possible to fix the Velocity (during the run) to the initial value of the function given in the corresponding General Data option. In order to do this, the corresponding Fix_Initial flag has to be marked.
For this example this condition is going to be assigned to the inflow line of the channel. Coincidentally, this happens to be similar as the Fixed Velocity condition used in the cavity flow example, the difference here is that the fluid now enters through this surface, whereas in the previous case it was only tangent to the surface to which the condition was assigned.
The options to be selected for the inflow surface are shown in Figure 46.
Figure 46 Initial Velocity Line condition |
Please note that the above condition will not work with the Start_up_control option (if Fix_Field flags are marked). Then this option must be switched off. It can be done through the Other Data window of the Data > Problem Data menu.
As mentioned in example 1, this condition is used to impose the velocity on a line. For this example this condition is going to be assigned to the step line (see Figure 47). Both velocity components will be set to 0.0 m/s. Then, all the velocity components have to be fixed to the specified value (i.e. mark Fix_X and Fix_Y).
Figure 47 Fixed Velocity Line condition assignment |
As
mentioned in example
Figure 48 Pressure Field condition |
|