To Design A Turbine

[tahoka]

theres a 3 HP pump having foll specifications :
Flow Rate : min= 2.2 litres/sec max= 4.1 litres/sec
Head Range : 15 m - 25m
overall efficiency : 40%
RPM : 2840

According to situation pump is on ground & has delivery head of roughly 1m & delivery pipe dia 6 cm. Now i have to DESIGN A TURBINE(i think Francis wud be gud) at its outlet to generate electrical energy by coupling a dynamo or electrical generator to turbine's shaft.
CAN ANYONE GIVE ME A BRIEF IDEA?

[Dougal]

If 40% efficiency is the goal (that's very low) then flat paddle blades will probably do the job.

You'll need to size the scroll housing to give you a flow speed at the tip that is higher than the turbine runner tip speed, I'd shoot for 1.5 times that for a start.