Aerodynamic investigation of the start-up process of H-type vertical axis wind turbines using CFD

Abstract

In this study, a CFD start-up model has been built after conducting the sensitivity studies to evaluate the selfstarting behaviour of the H-type vertical axis wind turbines (VAWTs). The self-starting behaviour of a wellinvestigated VAWT is used for the model validation, and then the details of aerodynamics of the start-up process have been examined. Finally, the effect of the moment of inertia and the blade number on the aerodynamic behaviour of the self-starting and power performance of the H-type VAWT are analysed. It has been found that in the critical region, where TSR<1, the contribution of the drag to the torque generation plays a significant role in the second and third quarters of the rotor revolution, where the azimuthal position varies between 100° and 253°. The results also show that increasing the turbine inertia did not show a noticeable effect on the start-up behaviour of the turbine and final rotational speed. However, an increase in the instantaneous turbine power during the start-up process after the optimum TSR is observed with decreasing the turbine inertia. The current findings also show that an increase in the blade number makes the turbine easier to start-up; however, this may reduce the turbine power coefficient.

Aerodynamic performance analysis and power generation characteristics experiment of vertical axis wind turbine

“…Its advanced fully implicit coupled multi-grid linear solver, parallel computing capabilities, and powerful post-processing capabilities are widely recognized. 19,20 Reasonable grid divisions and appropriate boundary conditions can make the simulation results of diagonal spiral blade wind turbine closer to the aerodynamic performance and flow field characteristics in the wind tunnel experimental environment. In this simulation, a mesh module in CFX software is utilized to divide the static and rotating domains since the shape of wind turbine blades in the rotating domain is not a regular figure, only automatic meshing may affect the simulation results.…”

“…In this article, ANSYS CFX software is utilized to finite element simulation analysis which the most widely used fluid mechanics simulation software, involving multiple fields. Its advanced fully implicit coupled multi‐grid linear solver, parallel computing capabilities, and powerful post‐processing capabilities are widely recognized 19,20 . Reasonable grid divisions and appropriate boundary conditions can make the simulation results of diagonal spiral blade wind turbine closer to the aerodynamic performance and flow field characteristics in the wind tunnel experimental environment.…”

Study of √2 Conjecture in the Construction of Drag Induced Wind Turbine Blade Morphology

“…In order to obtain 2.5D configuration, the 2D model is extended in spanwise direction but less than the actual blade length. 41) investigated H-rotor type VAWT self-starting behavior via CFD numerical analysis. In terms of CFD configuration, the simulation is based on pressure-based solver using SIMPLE algorithm as for pressure-velocity coupling.…”

Comparison of the Computational Fluid Dynamics Predictions of Vertical Axis Wind Turbine Performance Against Detailed Pressure Measurements

“…Currently, VAWTs power coefficients lack behind that of the HAWTs, but increasing research has been established in order to enhance VAWTs performance. Computational Fluid Dynamics (CFD) has been frequently used for turbine flow analysis and optimization [11]- [16]. A range of other modelling approaches with different fidelity has also been used to predict the performance of VAWTs and this includes the Double Multiple Stream Tube (DMST) [17]- [19] and the vortex method [20], [21].…”

“…Figure16 The baseline 3D mesh of the surrounding subdomain at the symmetric plane with a magnified view of the region near the rotor interface. The different colours represent different cell sizes, namely 0.2C, 0.4C, 0.8C, 1.6C, 5C, and 20C where C is the blade chord.…”