Investigation on the hydrodynamics of the catamaran hull of a floating tidal power generation device

Tidal energy as an alternative clean and renewable energy source has recently aroused much interest among both academia and industry. Floating tidal power generation devices are also under development worldwide. In this paper, hydrodynamics of the catamaran hull of a floating tidal power generation device is investigated using a CFD solver. As an initial step, the tidal turbine is not considered. Motion and force responses of the floating platform subject to regular waves are presented and analysed

Investigation on Darrieus type straight blade vertical axis wind turbine with flexible blade

In this study, a three-dimensional VAWT with a spanwise passively deformable flexible blade has been modelled. The study mainly focuses on the analysis of blade structure characteristics associated with the bending and twist deflection. Two types of flexible blade material and two strut locations supporting H-type blades are being investigated. The unsteady external loads and energy efficiency of VAWT with such designed flexible blade are also being analysed. The simulation results show that the bending and twist deflection peak is positively correlated with the turbine tip speed ratio λ. For a flexible blade, an unevenly distributed structural stress along the blade with a high stress regime in the vicinity of strut location has also been observed. Due to the rotational motion of a VAWT, the centrifugal force acting on VAWT blade plays an important role on the blade structure characteristics. Reduction of the blade stiffness results in an increase of the blade stress. Changing the strut location from middle to tip will cause a large area under high stress. The results also indicate that the VAWT with a highly flexible blade is not an efficient energy extraction device when it is compared to a less flexible or a rigid blade

Development of a fully coupled aero-hydro-mooring-elastic tool for floating offshore wind turbines

A floating offshore wind turbine (FOWT) is a coupled system where a wind turbine with flexible blades interacts with a moored platform in wind and waves. This paper presents a high-fidelity aero-hydro-mooring-elastic analysis tool developed for FOWT applications. A fully coupled analysis is carried out for an OC4 semi-submersible FOWT under a combined wind/wave condition. Responses of the FOWT are investigated in terms of platform hydrodynamics, mooring dynamics, wind turbine aerodynamics and blade structural dynamics. Interactions between the FOWT and fluid flow are also analysed by visualising results obtained via the CFD approach. Through this work, the capabilities of the tool developed are demonstrated and impacts of different parts of the system on each other are investigated

AMFlow: a Mathematica package for Feynman integrals computation via Auxiliary Mass Flow

AMFlow is a Mathematica package to numerically compute dimensionally regularized Feynman integrals via the recently proposed auxiliary mass flow method. In this framework, integrals are treated as functions of an auxiliary mass parameter and their results can be obtained by constructing and solving differential systems with respect to this parameter, in an automatic way. The usage of this package is described in detail through an explicit example of double-box family involved in two-loop $t\bar{t}$ hadroproduction.Comment: published version with 30 pages, 4 figures and 1 tabl