[JuanP]

Hi,

I am working on simulating a gravitational vortex turbine in ANSYS Fluent using the SST K-OMEGA turbulence model. The geometry consists of 4 interfaces with a total of 3716725 mesh elements. The simulation is transient, with constant inlet velocity and rotor rotational speed (mesh motion). The phase interaction (water and air) considers a surface tension coefficient of 0.032Nm and a "continuum surface stress" in the "surface tension force modeling". To optimize performance, the SIMPLE scheme and first-order equations have been used for the solution of the momentum, turbulent kinetic energy, and specific dissipation rate variables.

I have performed both fixed and adaptive simulations with a maximum of 100 iterations per time step. The time step size is 0.0001s for the fixed simulation and 0.00001s for the adaptive one, with a "global courant number" of 3 for the latter. Although the simulation converges correctly without errors, the simulation time is extremely slow. Simulating 3 seconds in transient takes about 250 hours in real time.

Question: Are there any suggestions to improve the simulation performance? Is it necessary to modify any parameters or settings to reduce the calculation time?

Additional Information:
ANSYS Version: 2024 R1
Processor: Intel(R) Xeon(R) Silver 4216
Logical Processors: 64
RAM: 128GB


Your suggestions are very much appreciated.