VMFL065

VMFL065
Swirling Turbulent Flow Inside a Diffuser

Overview

Reference P.D. Clausen, S.G. Koh, D.H. Wood. “Measurements of a Swirling Turbulent Boundary Layer Developing in a Conical Diffuser.” Experimental Thermal and Fluid Science. Vol. 6, pg. 39-48, 1993

Solver Ansys Fluent

Physics/Models

Turbulent flow, swirl velocity, Reynolds stress model for turbulence

Input File

VMFL065_FLUENT.cas

Project Files Link to Project Files Download Page

Test Case

Turbulent flow with a strong swirl component is modeled in an axisysmmetric diffuser. The swirl component of the velocity has a dominant effect on the flow field inside the diffuser.

Figure 155: Flow Domain

Material Properties	Geometry	Boundary Conditions
Density: 1 kg/m³ Viscosity: 1.293 X 10^-6 kg/m-s	Length of the straight inlet section = 25 mm Length of the diffuser (divergent section) = 510 mm Inlet Diameter = 260 mm Outlet Diameter = 440 mm	Fully developed turbulent profile for velocity, k and ε at inlet (with average axial inlet velocity = 1 m/s) No-slip condition at the walls

Material Properties

Geometry

Boundary Conditions

Density: 1 kg/m³

Viscosity:

1.293 X 10^-6 kg/m-s

Length of the straight inlet section = 25 mm

Length of the diffuser (divergent section) = 510 mm

Inlet Diameter = 260 mm

Outlet Diameter = 440 mm

Fully developed turbulent profile for velocity, k and ε at inlet (with average axial inlet velocity = 1 m/s)

No-slip condition at the walls

Analysis Assumptions and Modeling Notes

RS model is used for turbulence due to the strong swirl component.

Results Comparison for Ansys Fluent

Figure 156: Comparison of Swirl Velocity at X = 0.175 m