Lüthi, Beat

Company

Since 2012 Beat Lüthi has founded his own company photrack AG for image based measurements and consulting in particle tracking.

Contact photrack AG with any questions or ideas you might have in that direction!

Research

The hydromechanics group of IfU (Institute of Environmental Engineering) focuses on experimental research in complex, e.g. turbulent flows. Experimental facilities comprise a laser lab for table experiments, and flumes and tanks for larger scale experiments. The core competence is in three dimensional particle tracking (3D-PTV). 3D-PTV has been applied in measuring the full tensor of velocity gradients in isotropic turbulence, Raleigh Bernard convection, dilute polymer flows, entrainment in grid turbulence, bio-medical flows and in multi-phase flows.

Here is an overview over our lab activities.

Particle tracking velocimetry (3D-PTV) is a non-intrusive flow measuring tool that has been developed over several decades. An open source free software for 3D-PTV is available and documented here.

Recently, we made PTV experiments for turbulent entrainment in a turbulent flow that is subject to rotation.

With a fixed reference it looks like this

Publications

Journal of Fluid Mechanics

• Lagrangian measurement of vorticity dynamics in turbulent flow
• On the evolution of material lines and vorticity in homogeneous turbulence
• Velocity and temperature derivatives in high-Reynolds-number turbulent flows in the atmospheric surface layer. Part 1. Facilities, methods and some general results
• Velocity and temperature derivatives in high-Reynolds-number turbulent flows in the atmospheric surface layer. Part 2. Accelerations and related matters
• Velocity and temperature derivatives in high-Reynolds-number turbulent flows in the atmospheric surface layer. Part 3. Temperature and joint statistics of temperature and velocity derivatives
• A Lagrangian investigation of the small-scale features of turbulent entrainment through particle tracking and direct numerical simulation

Physics of Fluids

• Turbulence in dilute polymer solutions
• Experimental study of the structure of flow regions with negative turbulent kinetic energy production in confined three-dimensional shear flows with and without buoyancy
• Self-similar two-particle separation model

Experiments in Fluids

• 3D scanning particle tracking velocimetry

Physical Review E

• Stretching and tilting of material lines in turbulence: The effect of strain and vorticity
• Backwards and forwards relative dispersion in turbulent flow: An experimental investigation

Physical Review Letters

• Universal Intermittent Properties of Particle Trajectories in Highly Turbulent Flows

Journal of Turbulence

• Lagrangian multi-particle statistics

PhD Thesis

• Some Aspects of Strain, Vorticity and Material Element Dynamics as Measured with 3D Particle Tracking Velocimetry in a Turbulent Flow