FLUENT 6 - Tips for predicting vortex shedding with high Mach number and high Reynolds number flows in 3D
Flow domains that contain constrictions such as orifice plates may produce high Reynolds number and high Mach number flows with vortex shedding. This solution provides solution strategy tips for such flows.
Following solver settings will be useful:
(1) Single precision solver.
(2) Higher order discretization schemes: 2nd order for time, momentum, k, epsilon, energy and PRESTO for pressure.
(3) Change the reference values for area, length, temperature, and velocity according to the characteristics values of the problem.
(4) RNG model with differential viscosity option.
Start with segregated solver and small flow rate such that Re number lies in the range 10,000-50,000. This helps in gradually developing the correct flow field. Once the correct flow field (oscillating field) is established, increase the flow rate in steps and run the simulation for some time steps at every increase. If Mach No. reaches above 2.5 then switch over to coupled solver.