Aerodynamics of a wind turbine

Transcription

1 Aerodynamics of a wind turbine Author: Kosmacheva Anna Supervisor: Jari Hämäläinen Lappeenranta University of Technology Technomatematics

2 Introduction Wind turbine is a device that converts kinetic energy from the wind into mechanical energy. The smallest turbines are used for applications such as battery charging or auxiliary power on sailing boats. Large grid-connected arrays of turbines are becoming an increasingly large source of commercial electric power.

3 Defects of wind turbine blades There are some types of defects of wind turbine blades: Delamination Porosity Wrinkles/Cracks Influence of defects: Energy losses Noise generation

4 Problem statement Main goal - analysis of the performance of the wind turbine blades with and without defects Subject of research 2D-3D models of wind turbine blade, 3D wind turbine model Method Computational Fluid Dynamics (CFD)

5 Literature review 2D case M. Edon (2010) Numerical analysis of the Naca airfoils of a wind turbine blade J. Leary (2010) Computational Fluid Dynamics analysis of a low cost wind turbine H. Cao (2011) Aerodynamics analysis of small horizontal axis wind turbine blades by using 2D and 3D CFD modeling O. Badran Two-equation turbulence models for turbulent flow over a NACA 4412 airfoil at angle of attack 15 degree I.H. Abbott (1959) Theory of wind sections. Including a summary of airfoil data

6 Literature review 3D case S.N. Prasad, S.S. Rao Analysis of aerofoil blade using ANSYS for a vehicle mounted micro wind turbine S. Guntura, C. Bak Analysis of 3D stall models for wind turbine blades using data from the MEXICO experiment V. Sajjan, R.A. Savanur (2009) CFD analysis of 500 kw horizontal-axis wind turbine blades: straight and bent cases C. Ghenai, A. Sargsyan Wind energy

7 Literature review - Defects H. S. Toft, K. Branner Distribution of defects in wind turbine blades and reliability assessment of blades containing defects S.N. Ganeriwala, M. Richardson Modes indicate cracks in wind turbine blades Wind Energy Department, Risø National Laboratory (2002) Guidelines for design of wind turbines

8 Research plan (1) CFD analysis of 2D wind turbine blade model with different design The profile of DU93-W-210 The profile of NREL S809 Simulation of 2D model with some defects

9 Research plan (2) 3D modeling of rotating blades without any fixed objects

10 Research plan (3) Studying of rotating blades and stationary tower and some parts of the terrain

11 NACA 4412 The NACA airfoils are airfoil shapes for aircraft wings developed by the National Advisory Committee for Aeronautics (NACA).

12 Lift, drag and moment coefficients The lift is the force used to overcome gravity and the higher the lift the higher the mass that can be lifted off the ground. In order to maintain a constant speed the drag must be balanced by a propulsion force delivered from an engine, and the smaller the drag the smaller the required engine.

13 Flow in the vicinity of leading edge bubble

14 Stall angle NACA 4412

15 Mesh ANSYS ICEM QUAD elements

16 Computational conditions of aerofoil simulation Solver ANSYS FLUENT 13.0 Simulation Type Steady Simulation Fluid Material Air Wind Speed m/s Turbulent models RNG K-E, Spalart-Allmaras Boundary condition velocity inlet, pressure-outlet, Stationary wall with no slip shear condition

17 Numerical results Static pressure My results Khandakar Niaz Morshed [1] Inviscid, Angle of attack 2

18 Numerical results Velocity Magnitude My results Khandakar Niaz Morshed [1] Inviscid, Angle of attack 2

19 Numerical results flow separation Angle of attack 18 Angle of attack 20

20 Lift coefficient Comparison with experiment [2] Experiment 0.6 K-E RNG Spalart-Allmaras Angle of attack

21 References 1. Khandakar N. Morshed (2010) Experimental and numerical investigations on aerodynamic characteristics of savonius wind turbine with various overlap ratios 2. Robert N. Pinkerton Calculated and measured pressure distributions over the midspan section of the NACA 4412 airfoil

22 Thank you