SHADOW
Ship Hydromechanics Augmented with Diagnostical Optics in Waves
Future challenges like floating offshore energy and food production require advanced research infrastructure. SHADOW meets this need with a unique see-through towing tank and wave basin, enabling precise optical laser diagnostics. It allows full optical access for flow field and pressure measurements with unprecedented precision. The facility includes wave makers, flow pumps, and Stewart platforms with advanced control algorithms to study fluid-structure interactions of moving and floating systems. SHADOW is the first-of-its-kind, offering state-of-the-art tools to analyze waves, currents, and vessel motion. It provides high-quality data crucial for next-generation marine applications and offshore innovation.
Infrastructure and User Services
The SHADOW infrastructure will be located at TU Delft and operated by the Ship Hydromechanics and Fluid Mechanics groups. Designed for cutting-edge experimental fluid mechanics, it features fully transparent side walls and bottom, allowing all measurement equipment to remain outside the water. The primary techniques include tomographic particle image velocimetry (TOMOPIV), which provides the full 3D time-dependent velocity field, and scanning laser-Doppler velocimetry to measure time-dependent structural motions and deformations.
A key innovation is reconstructing the full pressure distribution on objects from TOMOPIV data—advancing beyond conventional force-only measurements. The towing tank and basin will be equipped with advanced wave generation systems. The basin features segmented wave boards for directional wave spreading and flow pumps to simulate underlying currents. Time-dependent wave fields will be measured using modern optical surface tracking methods instead of traditional point probes, enabling groundbreaking research on wave-current interaction.
Stewart platforms with complex control algorithms will manipulate model motions to study fluid-structure interactions in unprecedented detail. The combined use of TOMOPIV and scanning laser-Doppler velocimetry at this scale is a first in the field.
SHADOW supports research across maritime, offshore, civil, and aerospace engineering. The precision of TOMOPIV allows smaller, faster models, enabling exploration at high Froude numbers. The ability to capture full pressure distributions enables accurate force reconstruction on free-moving, self-propelled objects like submersible robots, robotic fish, and autonomous vessels. Applications also include hydrofoils, aircraft models, floating wind turbines, and water sports performance. This facility sets a new standard in scale, detail, and versatility for marine and fluid mechanics research.
Examples/description of the type of research
The infrastructure is suitable for investigating a wide range of structures from the fields of maritime, offshore, civil and aerospace engineering. The detailed data will open up new opportunities for investigating ship hydromechanics at model scale. The high accuracy of TOMOPIV makes it possible to investigate smaller models at higher (model-scale) velocities, i.e. much higher Froude numbers than currently can be reached in conventional towing tanks. Because the full pressure distribution is measured by default, a unique opportunity arises to reconstruct forces on free-moving self-propelled objects, such as submersible robots, (robot-)fish and autonomous ships. The facility will be well suited for investigating innovations for hydrofoils, airplane models and models of floating offshore wind turbines, in particular for studying flow control methods that reduce drag and control lift and the (far) wakes of these objects and structures. An upcoming field is to take measurements for performance prediction and improvement of sports in water, such as rowing and swimming. The infrastructure envisaged is going to take that field to an entirely new level of scale and accuracy.
How to access the infrastructure?
Access to the infrastructure is granted to researchers via short and regular projects. For both short and regular projects proposals have to be formulated. Short projects will only be evaluated on technical feasibily. Regular projects will be evaluated on scientific relevance and technical feasibility.