[etvan]

Hi dear all. im making simulation for 3kW micro class hydro turbine. in my case

1. components of turbine: spiral case, runner, draft tube.
2. mesh no of nodes 3.5 million near by wall has a prism mesh.
3. domain: steady state single phase /only water/, inlet of spiral case mass flow rate, outlet of turbine average static pressure, between casing and runner and runner and draft tube using general grid interface and frozen rotor interface. shear stress transport model is used

performance analysis was done at 0.02m3/s full load dishcarge and rotational speed is 1800rpm. but here something was wrong my efficiency is too high over 90%.

how can i improve the simulation?

[urosgrivc]

how can I reduce efficiency? -> hehe I haven't heard that one before

You must improve the simulation <- this is the answer. (stop and think at the end of this post if it helped you)

But you did not provide any data for the people that can help you.
So I think that nobody is able to answer this question YET.

Geometry?, mesh?, domains?, what hawe you already tried?....
There are infinite ways to suimulate a turbine, be more specific.

Try to ask a question that a person that doesent know what you are doing can answer, if you want to get an ansver otherwise this is the most help you can get:
http://www.cfd-online.com/Forums/sit...tml#post612025 (4)
http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F