There's a problem when I make stokesV wave in 2D empty flume made by hypermesh
 

Recently, when I try to check wave making in 2D empty flume, the Mesh by hypermesh make wave break or Strange vibration in postProcessing date.

I just "fluentMeshtofoam XXX.mesh", and checkMesh is ok.I didn't modify any setting except changing the water depth to 0.5 m.(I do these in the StokesV in interFoam of tutorials.)

when I use "interFoam" to run this simulation, it runs well.
but the result in postProcessing date(like wave surface) looks wrong, just not smooth and strange vibration.

https://s2.loli.net/2021/12/10/8qOkEtbRXNyeKhx.png

And I see there are strange phenomenon in inlet boundary.

https://s2.loli.net/2021/12/10/z8KGQTZlq1x7whC.png



when I try same size and density mesh made by Icem or blockMesh, all wave surface are great smooth.

https://s2.loli.net/2021/12/10/Ui6RZYPLzE27c1s.png

If there is anyone know this problem, and tell me how to deal it?
or
Is this problem made by hypermesh?

thanks everybody alot!