Abstract. Floating offshore wind turbines may experience large surge motions, which can cause blade–vortex interaction if they are similar to or faster than the local speed. Previous research hypothesized that this phenomenon represented a turbulent wake state even vortex ring state, rendering actuator disc momentum theory and blade element invalid. This hypothesis is challenged, we show valid ...

As far as the design of SPDs is concerned, the need exists for simplifying its circuit structure in fulfilment of the prerequisite condition of protective reliability. The circuit simplification for SPDs is of benefit to lower the cost of manufacture and reduce the size of chassis. Considering that the traditional SPD that has been extensively used on single-phase AC power supply lines requires...

CaCiiuAing ~lt.0 ,~,o;-e s;irge-pi-o;efiiiie devices located r p y ~ c t i ~ ~ l y rrt the serl@ce e ! ! ~ m c e c>f CI building ar~d near the sensitive equipment is intended to ensure that each device shares the surge stress in an manner commensurate with its rating, to achieve reliable protection of equipment against surges impinging fi-om the utility supply as well as internally generated su...

Metal oxide surge arresters (ZNO) are used widely in power system to protect equipments from over voltages. Non uniform potential distribution leads to the depressed service life and low safe reliability, so grading ring is applied on HV surge arrester order to uniform the electric field distribution. One of the problems of arresters is leakage current in power frequency that different paramet...

In this paper, the mooring dynamic loads and the motion responses of a large container ship in irregular waves with steady wind and current is investigated based on the commercial software AQWA. Comparisons between the time-history motion responses of a large container ship and the change of the mooring line tension in three different cases, non-mooring case, V-type mooring case and I-type moor...

Abstract The hydrodynamic characteristics are crucial for accurately analysing floating offshore wind systems. In this paper, the added mass and damping coefficients of a semisubmersible floater examined around natural periods surge, heave, pitch motion, using computational fluid dynamics (CFD). OpenFOAM CFD setup is validated against experimental measurements from free decay tests, same used t...

A sudden decrease in water depth, called a negative surge or expansion wave, is characterised by a gentle change in free-surface elevation. Some geophysical applications include the ebb tide flow in macro-tidal estuaries, the rundown of swash waters and the retreating waters after maximum tsunami runup in a river channel. The upstream propagation of expansion waves against an initially steady f...

The tension leg platform (TLP) is a vertically moored structure with excess buoyancy. The TLP is regarded as moored structure in horizontal plan, while inherit stiffness of fixed platform in vertical plane. In this paper, a numerical study using modified Morison equation was carried out in the time domain to investigate the influence of nonlinearities due to hydrodynamic forces and the coupling...