Numerical study of the flow around the high-torque wind turbine of vertical axis type

Numerical simulations of two-dimensional flows around a vertical axis type wind turbine are investigated. The turbines studied in this paper are the Savonius turbine and the cross-flow turbine of twelve blades. The governing equations are the incompressible Navier-Stokes equations. A rotational coordinate system, which rotates at the same speed of the turbine, is used in order to simplify the boundary conditions on the blades. Additionally, a boundary fitted coordinate system is employed in order to express the shape of the blades precisely. The fractional step method is used to solve the basic equations. A third order upwind scheme is chosen for the approximation of non-linear terms. The results are compared with experiments and agreements are reasonable.