Comparison of Experimental Measurements and Numerical Simulations for Vertical Axis Wind Turbine Wakes in an Open-Jet Wind Tunnel

Abstract

Energy made human life progress and science technology advanced faces an issue which the energy consumption increased Using the renewable energy is a method for solving the problem of energy scarcity the wind power generation has more interest in the countries around the world The wind turbines are according to their structures divided into vertical axis wind turbine (VAWT) and horizontal axis wind turbine (HAWT) The HAWT has commonly applied in open space and that the high efficiency at high wind speed However the VAWT has unlimited potential in power generation which the advantage is not a lot of restrictions on the site and the flow direction The research relevant the VAWT is mostly about the analysis and comparison of its performance characteristics The wake characteristics are also important for wind energy development In this study comparison of experimental measurements and numerical simulations for vertical axis wind turbine wakes in an open-jet wind tunnel which the wind turbine model is an airfoil NACA9412 four-blade VAWT The two kinds of experimental measuring instruments in the experiment which are the cobra probe and the hot wire probe for comparing the result between different measurement instruments In the CFD simulation part the transient Navier-Stokes equations are solved using the Large Eddy Simulation (LES) We use the SIMPLE algorithm in the split solver and the coupled algorithm in the coupled solver for solve and compare the wake characteristics The results were analyzed normalized time-averaged velocity of streamwise and spanwise the turbulence intensity for streamwise and spanwise and momentum flux at the horizontal plane The spectrum analysis with data collected using the cobra probe and the hot-wire probe shows the expected slope of -5/3 to indicate the inertial subrange which increases the reliability of the data measured in this experiment In order to develop the wind energy and accurate VAWT models that though the VAWT wake compaction of the measuring experiment and the CFD simulation

Date of Award	2018 Aug 10
Original language	English
Supervisor	Yu-Ting Wu (Supervisor)