# Temporal array filter on moving airfoil

**URL:** https://discourse.paraview.org/t/temporal-array-filter-on-moving-airfoil/12058
**Category:** ParaView Support
**Created:** [May 10, 2023, 9:57am UTC](https://discourse.paraview.org/t/temporal-array-filter-on-moving-airfoil/12058 "2023-05-10T09:57:48Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Dracool](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/d/eada6e/32.png) [@Dracool](https://discourse.paraview.org/u/Dracool)
#### Post date: [May 10, 2023, 9:57am UTC](https://discourse.paraview.org/t/temporal-array-filter-on-moving-airfoil/12058/1 "2023-05-10T09:57:49Z")

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Hi everyone !

I try to understand how the temporal array filter works for a moving airfoil. I have an overset mesh with the airfoil and I want to use the temporal array filter to get the temporal derivative (substract timestep 2 - 1). The thing is that it is an up and down moving airfoil (sinusoidal motion) and I don’t understand how it is supposed to work between 2 timesteps. Paraview succeeded to do it but it’s weird because if the airfoil is moving then there is a part of the airfoil that should be filled with the other timestep right ? You can see on the pictures attached the operations I did and a contour where you can see timestep 2 in grey and timestep 1 in red.

Do you have any ideas ?

![capture1](https://discourse.paraview.org/uploads/default/original/2X/9/9c680501a94e178d69a0e804daaada520d1cba01.png)

 ![capture2](https://discourse.paraview.org/uploads/default/original/2X/8/829c61c0d56cb3c1681c46eaa8b99e6f4fa5380d.png)