Research mathematicians and engineers have a major impact on a wide variety of fundamental industrial, geophysical and engineering problems, encompassing applications such as:

• fluid flow through permeable media (petroleum engineering and water resource and salinity management)
• clean combustion technologies (reducing greenhouse emissions)
• drag reduction and noise control (automobile, ship and submarine design)

All these applications require techniques from computational fluid dynamics combined with very powerful computers to produce reliably accurate solutions to the nonlinear equations governing fluid flow.

Access to eResearch SA facilities allows Australian researchers in computational fluid dynamics to remain competitive with US, European and Japanese researchers at the forefront of these fields. It also provides an attraction to international collaborators. eResearch SA facilities also support new initiatives in modelling the dynamics of plasmas in the space environment.

Numerical modelling of ocean waves

A scientist at the US National Weather Service/NOAA studying the contribution of ocean swell to the global wave climate began his research in Adelaide on eResearch SA computers. Dr Jose Henrique Alva is using numerical modelling to study ocean wave heights, which is important in areas such as oceanographic and meteorological studies, ship routing, engineering design and recreational activities.

Figure 1 (below left) shows the yearly average significant height of waves generated at high latitudes of the South Atlantic Ocean for 2001. Figure 2 (below right) shows the monthly mean significant height of waves generated at high latitudes of the South Indian Ocean during December 2001. Both figures show how far waves generated with-in a given ocean basin can penetrate into other oceans as swell, carrying significant amounts of energy over very long distances over the Earth. This information will be used to generate the first study of how global swell affects ocean wave conditions.

Dr Alves has collaborated on this project with Professor Ian Young (University of Adelaide), Dr Hendrik Tolman (NWS/NOAA) and Mr Fabricio Branco (University of Sao Paulo, Brazil).

Computation of flow over a long circular cylinder

Flow over long circular cylinders occurs commonly in engineering projects. A prime example is towed array sonar, where a cylindrical tube containing a series of hydrophones is towed behind a ship or submarine. The sounds detected by the hydrophobes can be processed to obtain information such as the bearing of neighbouring vessels or the possible locations of oil reserves. The turbulent flow of water over the surface of the sonar interferes with the detection of weak acoustic signals. Detailed study of such flows will be expected to lead to improved sonar designs and processing techniques. The figure shows a snapshot of the time varying flow speed near a stationary cylinder in axial flow, computed using a parallel program developed by Milton Woods, a doctoral student in mechanical engineering.