Extreme Free-surface Hydraulic modelling with a novel validation approach

Full three-dimensional simulation of extreme flows in rivers and man-made channels is not only difficult to model but also difficult to measure and thus validate. We are interested in looking at high-flow channels such as a flooding rivers around bridge piers or other structures which can cause rapid catastrophic scour, or reservoir overflow spillways which experience very large shear forces. We will also look at how these techniques can be used to design recreational water courses such as man-made kayaking channels or surfing ponds which require accurate prediction of the complex interaction between the moving and stationary surface waves.

In a preliminary study a novel application of terrestrial LIDAR has been used to provide detailed measurements of the position of the free-surface location in a full scale kayaking course. A three-dimensional transient RANS CFD-VOF model has predicted the position of waves within this complex hydraulic flow - while fairly successful it has some limitations particularly in respect of the geometry and computational requirement. This project will examine the potential of CFD with other free surface resolution schemes as well as mesh-free methods such as Smoothed Particle Hydrodynamics (SPH).