Master Classes

Description: The new OpenFOAM solver, sediDriftFoam2, computes sediment transport and the corresponding bed elevation changes in a three-dimensional geometry with a free surface. The formulas in the solver, the grid movements and the numerical algorithms are similar to what is used in the SSIIM model. The new solver was tested on estimation of local scour around a vertical cylinder, and the results corresponded reasonably well with the CSU empirical formula. The computational times for this case was from 2 to 58 hours on one core of an ordinary desktop PC, depending mainly on the grid size.

The Masterclass will go through the main principles and functionality of the solver, together with the grid generation. The most important parts of the source code will also be explained. The source code is freely available on the Internet.

Although the solver was only tested for local scour, it should also function on other cases with reasonable changes in the bed geometry caused by erosion and/or sediment deposition.

Details of the solver are given in the paper: Olsen, N. R. B., “Adaptive grid algorithms for computing local scour with OpenFOAM”, which has just been accepted to Journal of Hydroinformatics.

Organized by: Nils Reidar B. Olsen, NTNU, Norway

Duration: 3 hours

Speakers: Nils Reidar B. Olsen, The Norwegian University of Science and Technology, Norway

Description: Tool development for experimental characterisation of fluid flows is advancing rapidly, with new variants of established methods appearing frequently. This Masterclass introduces several state-of-the-art techniques, explains their core principles, and demonstrates their use in the laboratory, partly through hands-on activities. Participants will be divided into five groups, each working with one of the following setups in a rotating schedule:

• Educational Particle Image Velocimetry (PIV): Laser-illuminated tracer particles are used to measure 2D velocity fields in a jet and in flow past a cylinder.
• Particle Tracking Velocimetry (PTV) – open-channel flow: Individual particles are tracked to obtain 3D velocity fields and trajectories in a free-surface channel flow.
• Particle Tracking Velocimetry (PTV) – scaled turbine rig: Particle tracking is applied in a downscaled turbine test rig to map 3D flow structures and velocities.
• Micro-PIV: High-magnification PIV for measuring low-Re velocity fields in microchannels.
• X-ray tomography: Non-invasive 3D imaging to reconstruct internal structures and flows inside otherwise opaque systems.

LED-based illumination is used for the PIV and PTV setups, and X-ray tomography is employed for non-invasive 3D imaging. All demonstrated setups are based on commercially available systems.

Organized by: Sofia Larsson, Luleå University of Technology

Duration: 3 hours

Speakers:

Sofia Larsson, Luleå University of Technology, Sweden
Joel Sundström, Luleå University of Technology, Sweden
Fredrik Forsberg, Luleå University of Technology, Sweden