Talk:Francis turbine

Notes

Francis type units cover a wide head range, from 20 meters to 700 meters and their output varies from a few kilowatt to 1000 megawatt. Their size varies from a few hundred millimeters to about 10 meters.

Topology of the runner varies with the head.

Runners operate at constant rotating speed. Power varies according to net head and guide vane openings.

— Preceding unsigned comment added by Eric Demers (talk • contribs) 15:34, 9 March 2007 (UTC)

misstatement concerning water wheels

The article says "water wheels are inefficient" which is an overstatement that distorts historical fact. Early undershot waterwheels were grossly inefficient, usually less than 30%, but the later period overshot and backshot steel Fitz wheels and the Poncelet wheel have efficiencies comparable with the Francis turbine at considerably lower cost of manufacture. Unfortunately these innovations came after the turbine revolution, industrialists were not yet concerned about the excessive fish kill of bladed turbines, and (in the case of the Fitz wheels) costs of impoundment and diversion to a wheel are higher, so those designs were not widely adopted and have only recently re-entered production for environmental reasons. The Poncelet wheel is very nearly a turbine set sideways, although obviously it does not have axial flow like a Francis turbine. —Preceding unsigned comment added by 205.153.180.229 (talk) 13:33, 24 March 2011 (UTC)

Vertical-shaft question

thanks for giving me a chance to grow myself,I've a question about vertical shaft turbine that is there any loss in the velocity of water flow through turbine blades when the motion is just horizontal as compared to vertical in horizontal shaft turbine pls clear my topic(lalit gandhi)>(27-may-2011) — Preceding unsigned comment added by Lalit gandhi (talk • contribs) 05:39, 27 May 2011 (UTC)