Turbulent Swirling Flow

Analysis Characteristics

• Steady-state
• 2D internal flow
• Axisymmetric with swirl
• Turbulent
• Incompressible

Reference

So, R.M.C., Ahmed, S.A., Mongia, H.C., “An experimental investigation of gas jets in confined swirling air flow”, NASA Contractor Report 3832, (1984).

Problem Description

Turbulent, axisymmetric swirling flow is analyzed to verify the fluid flow and turbulence modeling capabilities of Autodesk® CFD. The k- turbulence model is used. The aim is to predict the same relationship between swirl or azimuthal velocity and radial location as that observed by So, et al. (1984).

There are two inlets in this problem, a centerline jet which has no swirl velocity component and an outer annular opening with swirl vanes yielding a swirl number of 2.25. Uniform velocity is specified at the two inlets based on the setup described by the experimenters.

A relatively large turbulence intensity is specified to correspond with the measured rms velocities.

Geometry and Boundary Conditions

Results

The slope is compared at a specific radial location for the numerical and experimental cases. The slope of the Autodesk® CFD results is then computed as:

Comparing the results: