Liang Yang

Liang Yang

Lecturer in Marine Renewable Energy Systems

Talks and presentations

Working with nature: retrofitting solutions for reducing mooring line loads.

April 06, 2022

Poster, WindEurope, Bilbao, Spain

This paper explores the usage of hydrofoil in offshore floating platforms to reduce the wave induced loads on the mooring lines. Inspired by the nature, thrust can be generated in the wake of flapping foil by reversed von Karman streets, which is mostly used in ocean propulsion systems. It presents preliminary experiments with a hydrofoil retrofitted in a semi-sub model structure exposed to regular and irregular waves. Although still at a very early stage, the preliminary results presented here show that retrofitting a hydrofoil in a floating platform can lead in positive gains at, primarily, the surge forces acting (in these cases) at the model structure’s centre of mass. Video Recording here

Hydrodynamic performance of submerged hydrofoils subject to heave and pitch motions

January 06, 2021

Talk, 2021 Supergen ORE Hub Annual Assembly, Online

Flow passing a foil object will produce lift and drag forces, as well as vortex street BvK. With right parameters, a periodic motion of an object in fluids will generate thrust rather than drag. To reduce the study’s complexity, only kinematics parameters were modified and not the geometric ones. The hydrofoil interactions with waves have been investigated using an inhouse CFD code. First, the lift and drag coefficients were validated against the literature. Thereafter, different oscillation parameters, according to the sea state, were studied to optimize the performance of the thrust. From these results it appeared that it is possible to generate thrust at sea state. The numerical model successfully represented the flapping foil interactions with water, the BvK reversed vortices and the leasing-edges vortices. It also allowed observing the global trend of the impact of the flapping motion on thrust generation. Video recording