Computational fluid dynamics

Understanding complex flow behaviour is critical to the safe design and operation of water management infrastructure.

Computational Fluid Dynamics (CFD) is a tool that allows us to analyse and visualise complex flow behaviour that can be difficult to observe in the field or assess with other techniques. By creating detailed computer models, we can assess hydraulic performance, investigate potential issues and test design improvements before construction. CFD complements other methods and can be applied at various stages during a water project.

Our specialists use CFD to investigate dams, spillways, weirs, stilling basins, gates, intakes, outlets, flumes, tunnels, pipes, canals, culverts, waterways and other hydraulic structures. We apply it throughout the asset lifecycle from option assessment and design development to performance verification and investigation of operational problems. CFD can quantify discharge capacity, flow distribution, water levels, velocities and pressure loads, and can reveal flow separation, cross-waves, hydraulic jumps, energy dissipation, air entrainment, cavitation, turbulence, erosion potential and vibration risks that influence safety, performance, constructability and asset life.

The example below demonstrates CFD modelling of flow over a weir. A low-pressure zone beneath the nappe causes the flow to cling to the downstream face of the structure. The simulation shows how a flow splitter admits air beneath the nappe, allowing the flow to separate cleanly from the downstream face and reducing the potential for unstable flow behaviour.