JP2858595B

PURPOSE:To prevent hydraulic pulsation from being generated by the draft core for improving the water turbine efficiency and axial vibration from being caused by this hydraulic pulsation, by eliminating the draft core generated by a swirling flow when a guide vane is contracted. CONSTITUTION:There are provide in an upper intake pipe 5 provided directly below a runner the first and the second guide vanes 9, 16 of streamline section which are divided into two pieces in such a manner as to traverse the upper intake pipe with the center being a boundary, and the first and the second guide vanes 9, 16 are interlocked with an opening/closing mechanism of the guide vane 2 and inclined to the opposite direction to each other and at the same angle so that the water flow from the runner outlet may be corrected.