Skip to content

Question on if low mach number Compressible flow can be simulated with NEK500 #157

Description

@elinlarsson744-ux

Hello,
I am simulating a CVD (Chemical Vapor Deposition) reactor and would like to know if Nek5000 is suitable for this type of problem. Below are the details of my case:
Problem description:
I have hydrogen gas (H₂) flowing through a heated reactor at sub-atmospheric pressure. The gas enters cold and gets intensely heated by the reactor walls and a rotating wafer surface. The key challenge is that pressure must be treated as a thermodynamic variable — density changes significantly due to heating, not due to high-speed flow.
Operating conditions:

Operating pressure: 200 mbar (20,000 Pa)
Inlet temperature: 300 K
Wall temperature: ~1600 K (heated by induction coils)
Inlet velocity: 2 m/s
Working gas: Hydrogen (H₂)
Mach number: ~0.0015 (deeply subsonic)
Reynolds number: ~36 (laminar)
Density variation: ~5× (0.016 kg/m³ at 300 K to 0.003 kg/m³ at 1600 K)
Rotating wall boundary (wafer at 6.62 rad/s)

I believe Nek5000's low-Mach formulation would be naturally suited for this regime since it removes the acoustic CFL constraint and avoids the pressure-density coupling issues I experienced in OpenFOAM. However, I am unsure about the feasibility of implementing multi-species reacting flow.
Geometry:
The reactor has a converging-diverging channel feeding into a rectangular reactor section (~0.15 m × 0.03 m × 0.287 m) with heated walls on all sides and a rotating wafer on the bottom wall. The mesh is currently ~8 million hexahedral cells in OpenFOAM.
Any guidance, references, or example cases would be greatly appreciated.
Thank you.

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions