[dccfd]

Hi guys,

I am currently trying to simulate the rotors of a drone mid-flight but keep getting this error:

ERROR #002100080 has occurred in subroutine CHECK_NORMV. |
| Message: |
| The specified velocity vector on the boundary patch |
| |
| ROTOR1 |
| |
| has a significant normal component at one or more faces. One of |
| these face locations is |
| |
| (x,y,z) = ( 5.81127E-01,-1.84382E-02, 1.36194E+00). |
| |
| The angle between the specified velocity and the element surface is|
| 68.169 degrees at this face. This is considered an error because |
| it implies that the mesh is moving. The following are possible |
| reasons for the error message: |
| 1. There is a setup error; for example, an incorrect axis of |
| rotation. |
| 2. There may be a meshing problem; for example, the nodes on a |
| rotating surface might not lie on the surface of revolution. |
| 3. The boundary is curved and the mesh is very coarse. In this |
| case, you may modify the tolerance by increasing the |
| expert parameter 'tangential vector tolerance wall' |
| from its default of 20 degrees.

I am pretty sure that the problem is with the axis of rotation as I have the rotors at an angle whereas the axis of rotation (y-axis) is vertically up. The hub is a perfect cylinder so I am unsure why the axis is in that direction.

If anyone could give me some advice on how to correct this, then that would be greatly appreciated.

Thanks!

[ghorrocks]

The error is simple and the error message is clear - the element at the specified location is a wall bondary which is not axial with the rotation axis. The message tells you exactly where this occurred, so you should be able to find it straight away.

Go into your meshing application and look at that location and find why an element face or faces are not axial, and fix it.