[snappyHexMesh] Modelling Rotor: To use MergeMeshes or not?

nialloneill · September 21, 2023, 06:45

Hello, I am modelling a wind turbine rotor and am trying to figure out the best way to do it.

For now I am using snappyHexMesh and am having significant difficulties getting a good snap quality. I have seen some examples where people create a mesh of the rotating region and a mesh of the non rotating region, and then merge the meshes after. Is this a good practice?

Thanks

Alczem · September 25, 2023, 04:48

Hey

It is what I usually do when I am not satisfied with snappyHexMesh. Make sure that the coupled patches match pretty well, and don't forget to change the boundary file to create the ACMIs once the meshes are merged together.

AtoHM · September 25, 2023, 08:00

my 2 cents:
When not using overset mesh, having stationary and rotating parts in the same model usually requires using different meshes and coupling through interfaces. So, what Alczem already states, plus I'd like to point out, that ACMI interfaces are not mass-conservative. openfoam.org has introduced a new interface algorithm called NCC which is mass-conservative and replaced ACMI in the recent releases: https://cfd.direct/openfoam/free-sof...rmal-coupling/

September 21, 2023, 06:45	Modelling Rotor: To use MergeMeshes or not?	#1
nialloneill New Member Niall O'Neill Join Date: Feb 2023 Posts: 16 Rep Power: 2	Hello, I am modelling a wind turbine rotor and am trying to figure out the best way to do it. For now I am using snappyHexMesh and am having significant difficulties getting a good snap quality. I have seen some examples where people create a mesh of the rotating region and a mesh of the non rotating region, and then merge the meshes after. Is this a good practice? Thanks

September 25, 2023, 08:00		#3
AtoHM Senior Member M Join Date: Dec 2017 Posts: 609 Rep Power: 11	my 2 cents: When not using overset mesh, having stationary and rotating parts in the same model usually requires using different meshes and coupling through interfaces. So, what Alczem already states, plus I'd like to point out, that ACMI interfaces are not mass-conservative. openfoam.org has introduced a new interface algorithm called NCC which is mass-conservative and replaced ACMI in the recent releases: https://cfd.direct/openfoam/free-sof...rmal-coupling/ Alczem likes this.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
How much does the source code for this turbulent flow CFD code worth in US $?	Dr Youssef Hafez	Main CFD Forum	43	January 4, 2023 02:13
Setting the height of the stream in the free channel	kevinmccartin	CFX	12	October 13, 2022 22:43
Low-Re Modelling	doerschlott	OpenFOAM Running, Solving & CFD	4	June 23, 2022 07:53
Domain Reference Pressure and mass flow inlet boundary	AdidaKK	CFX	75	August 20, 2018 06:37
CFD in Naval Hydrodynamics, Off-Shore and Wave Modelling with OpenFOAM	hjasak	OpenFOAM Announcements from Other Sources	2	February 13, 2017 05:59

September 25, 2023, 04:48		#2
Alczem Senior Member Join Date: Dec 2021 Posts: 162 Rep Power: 3	Hey It is what I usually do when I am not satisfied with snappyHexMesh. Make sure that the coupled patches match pretty well, and don't forget to change the boundary file to create the ACMIs once the meshes are merged together.