Numerical Study of the Flow Around a Straight Darrieus Turbine

抄録

Darrieus wind turbine is a kind of vertical axis wind turbine (VAWT) with attractive characteristics such as the ability to accept wind from random direction and easy installation and maintenance. But the flow around the wind turbine is very complicated especially for its dynamic stall which affects the efficiency of the turbine. In order to investigate the aerodynamic phenomena of straight Darrieus wind turbine, the flow around the turbine is simulated by solving the two-dimensional unsteady Navier-Stokes equation combined with continuous equation. The time marching method on a body-fitted coordinate system based on MAC method is used. O-type grid is generated to the total calculation domain. Different Reynolds number cases based on oncoming inflow and chord length of blade of turbine are calculated. In order to compare the numerical results to similar experiments done by Sandia National Laboratory of USA, NACA0015 section is selected as the wind blade section. The characteristics of tangential and normal force are discussed related with dynamic stall of the blade. Averaged Power coefficient per period of rotating is calculated to evaluate the eligibility of the turbine.