# Aircraft fin Local deflection angles

**URL:** https://discourse.paraview.org/t/aircraft-fin-local-deflection-angles/16438
**Category:** ParaView Support
**Created:** [April 5, 2025, 11:37pm UTC](https://discourse.paraview.org/t/aircraft-fin-local-deflection-angles/16438 "2025-04-05T23:37:49Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![tabarek](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/t/b38774/32.png) [@tabarek](https://discourse.paraview.org/u/tabarek)
#### Post date: [April 5, 2025, 11:37pm UTC](https://discourse.paraview.org/t/aircraft-fin-local-deflection-angles/16438/1 "2025-04-05T23:37:49Z")

</div>

Hello everyone,  
I am a new ParaView users so apologize me if this seems basic.  
I created and meshed an aircraft geometry using Gmsh. I need to find the deflection angles along the fin (theta shown in the attached image) using ParaView.

I used clip tool to split the fin from the aircraft and started by computing the surface Normals at each point and taking atan (normal\_z/normal\_x) to find these angles, but I am little confused whether the data I’ve saved is ordered in term of (X,Y,Z) or there are any missing steps that I need to consider. I would really appreciate any guidance. ([https://aerospaceweb.org/design/waverider/figures/fig09.jpg](https://aerospaceweb.org/design/waverider/figures/fig09.jpg))