In order to improve the performance of a Wells turbine, the porous fences have been equipped on the hub wall upstrem and downstream of the rotor. The effects of the gap between the porous fence and rotor, porosity and height of the porous fence have been investigated by model testing. The results have been compared with those of the case without porous fences. As a result, it is found that the starting characteristics are improved by the porous fences. Furthermore most of the configurations tested have shown improvements in the operation range primarily by postponement of stall. A suitable choice of design parameters for the turbine has been suggested.
