The new OTTER facility stands for Optical Towing Tank for Energetics Research. With a cross-section of 1m x 1m and an overall length of 15m, the high-speed traverse system is able to hit Reynolds numbers on the order of a million. The ceiling is sealed to prevent free-surface effects (sloshing) but free-surface testing can be accommodated by lowering the waterline slightly. Optical measurement techniques such as time-resolved PIV and 4D-PTV are employed for direct flow measurements. An ATI Nano submersible six-component balance is used for direct force and moment measurements. For more details on this new world-class facility please see the following:


OTTER II maintains the same cross-section as OTTER I at 1m x 1m but with a shortened overall length of 8m. The focus of this facility is on two-phase problems such as particle-laden flows, where a custom shear generator is towed through to generate turbulence in the medium. Planar and volumetric imaging techniques such as PIV and PTV are employed here.

Octagonal Tank

The octagonal tank offers ideal optical access for 4D-PTV measurements, with an HID light source situated beneath the tank. The six degree-of-freedom hexapod manipulator is used to translate and/or rotate models around arbitrary points of rotation. An ATI Gamma six-component balance is used to measure forces and moments.

Pulsatile Flow Loop

This large-scale, temperature-controlled flow loop provides an environment to study steady and unsteady (pulsatile) flows over a broad range of Reynolds numbers. Single-phase as well as two-phase flows – both dilute and dense suspensions – are possible via a specialized pumping system. The optical test section allows for index-matched stereoscopic and tomographic reconstructions for complex geometries. Acoustic access for echo-PIV reconstructions is also foreseen.