Initial results of an ongoing Navier-Stokes Computational Fluid Dynamics study of horizontal axis tidal current turbine hydrodynamics are presented. Part of the underlying motivation is assessing the effects of the Reynolds number on turbine performance and loads in steady and unsteady flow regimes. The study aims at a) providing initial verification and validation of Navier-Stokes CFD for stea...

When it comes to measuring blade-tip clearance or blade-tip timing in turbines, reflective intensity-modulated optical fiber sensors overcome several traditional limitations of capacitive, inductive or discharging probe sensors. This paper presents the signals and results corresponding to the third stage of a multistage turbine rig, obtained from a transonic wind-tunnel test. The probe is based...

A power criterion for selecting the electric motor used in a gas turbine emulator is defined. The power criterion is derived in terms of the ratio of inertias between the gas turbine engine and the electric motor, rotational losses and load torque. The gas turbine emulator allows emulating the speed-torque behavior of a gas turbine engine. Using simulation models, we show that the steady-state ...

The ongoing trend towards larger wind turbines intensifies the demand for more physically realistic wind turbine rotor aerodynamics models that can predict the detailed transient pressure loadings on the rotor blades better than current engineering models. In this report the mathematical, numerical, and practical aspects of a new wind turbine rotor flow simulation code is described. This wind t...

At present, the radius of wind turbine rotors ranges from several meters to one hundred meters, or even more, which extends Reynolds number of the airfoil profile from the order of 105 to 107. Taking the blade for 3MW wind turbines as an example, the influence of Reynolds number on the aerodynamic design of a wind turbine blade is studied. To make the study more general, two kinds of multi-obje...

Tidal Stream Turbines are developing renewable energy devices, for which proof of concept commercial devices are been deployed. The optimisation of such devices is supported by research activities. Operation within selected marine environments will lead to extreme dynamic loading and other problems. Further, such environments emphasise the need for condition monitoring and prognostics to suppor...

During the design of a two-bladed turbine a very important load reducing feature is the teeter mechanism. This mechanism enables a free rigid body motion of the blades relative to the hub in such a way that bending moments between rotor and hub are removed around the teeter axis. Due to the practical issues such as the clearance between blade tip and tower, the teeter angles must be limited as ...

To analyze the complex and unsteady aerodynamic flow associated with wind turbine functioning, computational fluid dynamics (CFD) is an attractive and powerful method. In this work, the influence of different numerical aspects on the accuracy of simulating a rotating wind turbine is studied. In particular, the effects of mesh size and structure, time step and rotational velocity have been taken...

In general, there are three components making up a lightning protection system for wind turbines. These are the receptors, the down conductor and the grounding grid. Receptors and down conductors are usually found in the more recent wind turbine blades and where the down conductors are normally installed on the internal side of the blade. Consequently, the blades are vulnerable to damage and bu...

A wind turbine blade's structural dynamic response is simulated and analysed with the goal of characterizing the presence and severity of a shear web disbond. Computer models of a 5 MW offshore utility-scale wind turbine were created to develop effective algorithms for detecting such damage. Through data analysis and with the use of blade measurements, a shear web disbond was quantified accordi...