Development of robotic volumetric PIV

Development of robotic volumetric PIV: with applications in sports aerodynamics

Jux, C. (TU Delft Aerodynamics)

Scarano, F. (promotor)
Sciacchitano, A. (copromotor)

Delft University of Technology

2022-03-16

Particle image velocimetry (PIV) is the state of the art for quantitative, full-field, 3D flow diagnostics. Despite the maturity of the technique, two bottlenecks are identified which are addressed in this thesis: the achievable measurement volume size, and the optical access to geometrically complex objects. Both aspects are well illustrated when considering the human body in sports action. Characterising the aerodynamic flow topology around an athlete demands measurement volumes on the cubic-meter scale, whereas the simultaneous illumination and imaging of the flow near the athlete’s body is challenged by the geometric complexity of the human body and the sports equipment. Focusing on sport performance, especially in timed disciplines, it is recognized that due to the shape of the human body, the aerodynamic resistance is often dominated by pressure drag. Therefore, a third element addressed in this thesis is the PIV-based pressure evaluation in the flow and on an object surface.

To overcome the identified measurement constraints, a PIV system for the 3D diagnostics of large-scale and low-speed flows has been developed, synthesizing advancements in PIV imaging and illumination hardware, automation technology, tracer particle generation, and particle tracking algorithms. The so called robotic volumetric PIV concept is proposed in Part I of this thesis, along with dedicated data analysis methods to retrieve the shape of the test object, the total pressure in the fluid flow, and the aerodynamic pressure on the object surface. Part II features applications of the proposed tools in the context of sport aerodynamics, with specific examples in cycling and swimming.

Quantitative flow visualization
Particle Image Velocimetry (PIV)
Pressure measurements
Low speed aerodynamics
Sport aerodynamics
Robotic PIV
Coaxial volumetric velocimetry

https://doi.org/10.4233/uuid:643a6936-ce92-4c3e-af0f-5c251a50abbe

978-94-6366-519-3

Institutional Repository

doctoral thesis

© 2022 C. Jux