Designing a Hydro Turbine

Find a copy Alexey Stepanoff's book Centrifugal and Axial Flow pumps, Theory, Design, and Application. Publisher John Wiley, 2nd ed 1957. Reprinted by # Krieger Publishing Company. Date: April 1993 # ISBN-13: 9780894647239.

A Google search will bring up a number of used copies for sale both from USA and UK major booksellers.

Chapter 8 gives a good overview of Axial pump design and should get you well beyond the level of your first questions. From that point you should be knowledgeable enough to understand the design variations between the pump application to the purpose designed water turbine as would be discussed in works on that subject.

Hopefully someone else can advise you on good references specific to large francis turbine design since these machines are fairly distant from my own experience.

Ed Weldon

I would suggest you get the help of an engineering team specialised in computing flows since the form and number of blades can very much influence the efficiency. The same is valid for the stator.

I would recommend Canyon Turbine of Canada and a design consult resource.

The specific speed you mention is too high for Francis. If I were you , I would go with Kaplan.

Normally hydro turbine designers have a family of Turbine designs from which they choose the closest fitting turbine with the specific speed identified and then they scale up or down the model to suit the head, Flow rate and Turbine speed requirement.

However, if you would like to go from First principles then you need to decide first as to how many bladed turbine you wish to provide. Based on that you need to decide on how you would like to direct the water from the penstock onto the blades. this should help in finalizing the angle of incidence on to the blade. Being a Francis turbine you know that the water flow should be in the radial direction and out through the hub side. During this period the work is done. hence plot the velocity triangle on the leading edge and the trailing edge of the blade. Play with the blade profile and curvature to ensure that you get the maximum radial force on the runner and minimum axial force. ........ AND you would have designed your runner. as regards the Guide vanes, you could decide the number and size based on the circumference that you need to cover. 24 - 28 guide vanes should be a fairly good number of guide vanes.

All I state above is very simply put. however, this should let you think in the right direction.

All the best.