Numerical simulation of bow thruster induced near-bed flow next to quay wall

Numerical simulation of bow thruster induced near-bed flow next to quay wall

Haafkes, Thom (TU Delft Mechanical, Maritime and Materials Engineering)

van Terwisga, T.J.C. (mentor)
de Koning Gans, H.J. (graduation committee)
O'Mahoney, T.S.D. (mentor)
van der Hout, A.J. (graduation committee)

Delft University of Technology

Marine Technology

2021-05-21

During berthing operations of ships, the horizontal thrusters cause a hydraulic load on the quay wall and bed. This could eventually lead to scour holes in the bed, which may affect the structural integrity of the quay wall. This thesis is about a numerical simulation of a bowthruster jet which is deflected by a quay wall and the focus of this study will be on the resulting bottom velocities. In 2019, field measurements were executed with an inland vessel and the measured bottom velocities were low compared to the design guidelines. The goal of this study is to simulate the field measurements in a numerical model to gather more knowledge about the flow field induced by bowthrusters next to quay walls. The obtained numerical results are compared to the field measurement and to the design guidelines of PIANC. As it turns out, the velocity sensors probably did not measure the maximum bottom velocity during the field measurements, since they are located slightly above the highest velocities at the bottom, as predicted by the numerical simulations. The maximum bottom velocities from the numerical simulation are similar to the expected near-bed bottom velocities by PIANC. However, there is room for improvement in these design guidelines, e.g., adjusting the efflux velocity for tunnel thrusters to account for the variation in cross-sectional area between propeller and tunnel exit.

CFD
Propeller jet
Bow Thruster
Scour
Quay walls

http://resolver.tudelft.nl/uuid:a3768fea-74e0-42e7-b2c4-b4c5a85ea98e

Student theses

master thesis

© 2021 Thom Haafkes