Experimental Analysis and Evaluation of the Numerical Prediction of Wake Characteristics of Tidal Stream Turbine

Abstract

Abstract:It is important to understand tidal stream turbine performance and flow field, if tidal energy is to advance. The operating condition of a tidal stream turbine with a supporting structure has a significant impact on its performance and wake recovery. The aim of this work is to provide an understanding of turbine submerged depth that governs the downstream wake structure and its recovery to the free-stream velocity profile. An experimentally validated numerical model, based on a computational fluid dynamics (CFD) tool, was present to obtain longitudinal, transverse and vertical velocity profiles. Wake characteristics measurements have been carried out in an open channel at Hohai University. The results indicate that varying the turbine proximity to the water surface introduces differential mass flow rate around the rotor that could make the wake persist differently downstream. CFD shows the same predicted wake recovery tendency with the experiments, and an agreement from CFD and experiments is good in the far-wake region. The results presented demonstrate that CFD is a good tool to simulate the performance of tidal turbines particularly in the far-wake region and that the turbine proximity to the water surface has an effect on the wake recovery.

Computational Fluid Dynamics Modelling and Simulation of an Inclined Horizontal Axis Hydrokinetic Turbine

“…Moreover, the turbine closeness to the water surface promoted the flow modification around the turbine which affected the wake development downstream the rotor. Finally, supported by the presented results, Zhang et al [16] claimed that CFD is an appropriate tool to simulate the performance of tidal turbines and that the turbine proximity to the water surface influences the wake recovery.…”

“…When comparing with experimental data, Reference [15] found that both models captured reasonably well the wake dynamics, although there was around a 5% difference between both predictions. Reference [16] presented comparisons between experiments and CFD numerical computations focused on the velocity profiles in the wake region of a HAHT. The agreement between them was very reasonable, showing the same predicted wake recovery trend.…”

Multiobjective Optimization Design and Experimental Investigation on the Axial Flow Pump with Orthogonal Test Approach

“…ICEM CFD software was used to obtain the mesh of the computing domain [14]. e unstructured grids were adopted due to its strength in the adaptability of the complicated and irregular geometry.…”

“…Although several approaches exist for the purpose of multiobjective optimization design of the pumps and impellers, programs using computational uid dynamics (CFD) continues to be the most popular method [10][11][12]. ese programs, when run by high-performance computers, can forecast not only the functioning of the pump but also the ow eld upstream and downstream of the pump [13][14][15]. For instance, Zhang et al [16] validated a CFD model, used for optimizing the submerged propeller operated in an oxidation ditch.…”

Analysis on Guide Vane Closure Schemes of High‐Head Pumped Storage Unit during Pump Outage Condition

“…e transient process model of pumped storage unit was solved by using the method of characteristics, and the basic motion and continuity equation of unsteady flow in pressurized pipeline are shown below [28][29][30][31][32].…”