COMPUTATIONAL FLUID DYNAMICS (CFD) IN AEOLIAN RESEARCH

Aeolian landforms are features created by the erosion and deposition of sediment by wind. Landforms range in spatial scale from centimetres to kilometres and incorporate a range of structures including: ripples, ventifacts, yardangs, dunes and blowouts. These landforms exist on all earths’ continents as well as Mars, Titan and Venus.

Wind flow over a flat surface can be described using a logarithmic velocity profile, however as flow approaches an obstacle, changes in pressure cause wind flow to alter in both speed and direction. Much research has been devoted to measuring wind flow over aeolian landforms in an effort to understand the complex airflow patterns which influence their morphology and evolution. Increasingly near surface wind flow has been calculated using computational fluid dynamics (CFD) and since 2004, CFD has been performed in approximately 30 peer reviewed articles regarding aeolian research.

CFD uses numerical algorithms which integrate the governing equations of fluid flow and solves them iteratively. It has a number of advantages compared to field anemometry and wind tunnel studies. In particular, it permits the visualisation of velocity, pressure, turbulence and shear stress throughout a landform at high resolution. It also permits wind flow to be investigated at a range of incident wind conditions at sites that would be difficult and/or expensive to instrument.

This presentation highlights several applications of CFD in aeolian research to date, discusses some of the current difficulties with the method and demonstrates what future research may be performed.