Welsh, M., Pullum, L., Downie, R.J., Cooper, P.I. and Blackburn, H.

Fluid dynamic processes have been studied using small-scale physical models for many years. In particular, the aeronautics industry has made extensive use of wind tunnels and small-scale models to study the complex flows around aircraft, while the motor vehicle industry utilises a similar approach to study the aerodynamics of vehicles and their cooling systems.

Since the 1950s, small-scale physical models and wind tunnels have also been used to study the flows around buildings, and in the 1960s and 70s the Advanced Fluid Dynamics Laboratory (AFDL) of the CSIRO used small-scale physical modelling to develop fans and diffusers for mine ventilation systems.

Recently, the AFDL physically modelled a range of mineral processing equipment to solve significant problems encountered in the alumina industry. For these cases, single-phase liquids were used to model slurries in mixing tanks, while water was used to model the flows in an electrostatic precipitator. Slurries have also been developed which are optically clear, with the liquids and the solids having the same refractive indices.

Using experience gained by the researchers and computational fluid dynamics, the small-scale physical model results were scaled up to plant size and successfully trialled in the full-size installations. The reduced operational costs after modifying the plants in accordance with the recommendations of the small-scale physical modelling are substantial.

Successful collaboration on a project between industry and CSIRO is critically dependent on there being close communications between both parties throughout the project.

This paper has a companion video which illustrates the small-scale physical modelling techniques used at the AFDL.