Above discussion relate to the change in direction of velocity vector without changing element direction vector.

Now I test 3 lines in same run with input order as below (keeping fluid direction no change in +Z, and changing element direction vector, but all 3 lines have the same configuration and boundary conditions):

Line 1: 10-20 X=+6000mm, 20-30 X=+6000mm
Line 2: 120-130 X=+6000mm, 120-110 X=-6000mm
Line 3: 230-220 X=-6000mm, 220-210 X=-6000mm

Node 20 coordinate: 0,0,0
Node 120 coordinate: 6000,0,3000
Node 220 coordinate: 6000,0,6000

Load case is WAV1 only

Typical output Fy is showing:
- Node 20 : Fy < 0
- Node 120: Fy = 0
- Node 220: Fy > 0
---------------------------
- Node 10: Fy < 0
- Node 110: Fy > 0
- Node 210: Fy > 0
---------------------------
- Node 30: Fy < 0
- Node 130: Fy < 0
- Node 230: Fy > 0

The restraint load at one specific location is changing because of changing of element axis direction (From-To) during input activity even the 3 lines are same in configuration, boundary condition and fluid direction

My question: which line match the real world?