The performance of a horizontal-axis cross-flow wind turbine and the flow field above a porous windbreak fence in oblique wind were investigated in a circuit-type wind tunnel with a semi-open test section by using scale models of the fence and the wind turbine. The inclined angle, θ, between the turbine and the flow direction was changed from 0? to 40?. The maximum power coefficient of a cross-flow wind turbine in the oblique wind was proportional to cos2θ. In order to suppress the decrement of power, the fixed end plates were installed at both ends of the cross-flow wind turbine. The power coefficient of the cross-flow wind turbine with the fixed end plates is higher than that without the fixed end plates at θ = 40?. The fixed end plates were effective in suppressing the decrement of power in oblique flow. Moreover, in order to obtain the same effect in the turbine located above a porous fence, the effect of deflector which was installed in front of a porous fence was also investigated. The maximum power coefficient of the cross-flow wind turbine located above a porous fence with deflectors at θ = 40? is higher than that without deflectors. In oblique flow, a cross-flow wind turbine located above a porous fence with deflectors is expected to produce more power than that of the porous fence without deflector.
