The new case study regarding a centrifugal pump simulation with a partial interface overlap. The primary purpose of the case study is to demonstrate a new software feature called Non-Conformal Coupling (NCC) (OpenFOAM.org).
Here is a summary of the key points:
1. Objective
The project uses an artificial centrifugal pump test case to showcase the capabilities of the NCC interface. This functionality is designed to handle simulations where different parts of a machine (like a rotor and a volute) have meshes that do not perfectly line up or only partially overlap.
2. Key Technology: NCC vs. AMI
NCC (Non-Conformal Coupling): Unlike the older AMI (Arbitrary Mesh Interface) method, which relied on interpolation, NCC calculates the actual geometric intersection of the mesh faces.
Benefits: It ensures a “strictly conservative” transfer of fluxes (mass, momentum, energy) across the interface. It is more robust, reduces numerical errors, and allows for much more flexible mesh configurations where surfaces only partially touch.
3. Simulation Setup
Components: The model is split into three parts: the inlet pipe, the rotating impeller (rotor), and the stationary casing (volute).
Conditions: The simulation is “pressure-driven” (fixed pressure at inlet and outlet) rather than flow-rate driven, which provides a more realistic physical result for this setup.
Physics: It uses an incompressible water model at 300 RPM, employing the $k-\omega$-SST turbulence model.
4. Results & Availability
Performance: The NCC interface successfully handled the “partial overlap” between the rotor and the volute, maintaining a smooth pressure distribution and consistent flow.
Resources: The website provides 2D and 3D visualizations of velocity streamlines and pressure distributions.
Download: A full tutorial package (approx. 24 MB) including the geometry and setup files is available for users who want to practice using the TCAE software environment.
In short, it’s a demonstration of how modern CFD tools can more easily simulate complex rotating machinery even when the internal parts don’t perfectly align geometrically.