Turbulence models for CFD in the 21st century
Brian Spalding, of CHAM Ltd
Invited lecture presented at ACFD 2000, Beijing
Example 1. The LVEL turbulence model used in a simultaneous solid-stress,
fluid-flow and heat-transfer example
- Heat is supplied to a fluid in which a horseshoe-shaped object is
- The outer cylindrical container is cooled.
- The task is to compute the stresses in the solid.
- The following images are shown:
The thermally-induced volumetric expansion of the solid
The temperature distribution in the solid and fluid, when heat is
supplied along the axis, and gravity acts vertically
The associated velocity vectors (in the fluid) and displacement vectors
(in the solid)
The thermally-induced radial stresses in the solid
The thermally-induced circumferential stresses in the solid
The computed distance from the walls, needed by the underlying LVEL model,
- the horseshoe-shaped solid, and
- an outer cylinder
The effective viscosity determined by the LVEL model
The effective viscosity is evidently greatest where the buoyancy-driven
velocity is greatest, and the distance from the wall not too small.
The equations for the wall-distance, effective viscosity, velocities,
temperatures and displacements, are all solved simultaneously by
means of a single computer code (PHOENICS).
The computer time is not significantly greater than would be
taken for the velocities and temperatures alone.