Turbulence & Time Stepping
Every turbulence & time stepping calculator on CalcEngines — each with its formula, a worked example, the standard it follows and the assumptions it makes.
3 calculators in this section
- Courant Number (CFL) & Time Step CalculatorCFL from velocity, cell size and time step, and the time step a target CFL needs — judged against the limit that applies to YOUR solver, because an explicit scheme diverges above 1 and an implicit one is stable at 50 and wrong. Plus the vortex-shedding constraint, the total step count and the wall clock.
- LES / DES Affordability CalculatorWhether a scale-resolving run is affordable, answered before a week of cluster time is committed. Cell count, time step, step count and core-hours for wall-resolved LES, wall-modelled LES and DES, with the Reynolds-number exponent derived rather than quoted, and an honest statement of what the estimate does not know.
- Turbulence Inlet Conditions CalculatorTurbulence intensity, length scale, k, ε, ω and the eddy-viscosity ratio from one velocity and one length — with νt/ν checked against the band ANSYS Fluent actually names, because that is the number that tells you whether the inlet you just typed is sane.