Steam Turbine Blade Design Resources

[poetix99]

I am looking for software and/or consulting resources to perform (or assist in) the aero/thermo design and analysis of a new “airfoil” profile for the rotating blades of steam turbine. Experience with turbomachinery (as distinct from wing design) is required.

I used the word “airfoil” in quotes because the rotating blades must be nominally an impulse type of design. Specifically:
- Very high amounts of fluid turning in the direction of blade disk rotation.
- Very small amount of the total stage pressure drop is across the rotating row (0 - 15%).

The shape that I want is definitely not a "classic" airfoil shape, and its application is in a bladed disk assembly without a free stream as such.

I am relatively new to Eng-Tips and have reviewed many of the threads in the Aero Engineering Forum, Turbine Engineering Forum, etc.

Because of the characteristics of my application (typical of impulse turbines), some of the inexpensive (and otherwise useful) design s/w such as “CompuFoil” (ref. thread 1-2543) is not directly applicable.

I have located some prospects through web-searches and will continue to explore these leads. Any suggestions will be appreciated and followed-up.

Thank you.

 

[insideman]

For an impulse turbine, the velocity through the passages between the blades at a given radius is a constant. Therefore concentrate on making the space between the blades a constant width. The result will look nothing like an airfoil!

 

[poetix99]

Thanks, "insideman".

Yes, I realize that the constant velocity is, essentially by definition, characteristic of impulse blades. They certainly don't look like classic airfoils (they're often called "buckets" - evocative of the scoops of water wheels) because of the high amount of turning, or camber if you will.

However, there have been various improvements in the profile shapes over the last forty years. Newer profiles better supress flow separation - even with the overall "favorable pressure gradient" of an expanding device like a turbine, the flow still wants to separate because of the high amount of turning in an impulse design. Secondary flows in the blade passage can also be supressed with proper design. The stage efficiency is thereby improved if the flow stays attached and streamwise.

CFD facilitates these newer designs (or an arduous, graphical version of a Schwartz-Christofelson laminar inviscid co-ordinate transformation, which I can say, but can't do).

Most OEMs have proprietary designs and it is therefore necessary for me to develop a profile of my own, if not on my own. So, I'm really looking for are some leads on CFD analysts who might be willing an able to do this work.

Thanks again.

 

[walkerny]

We do not do redesign, but we manufacture prototypes (such as for GE or Conmec) and new sets of replacement turbine blading.

joe.walker@storkhe.com

Joe Walker / Stork H&E Turbo Blading. Steam turbine blades, buckets, nozzles, gas turbine compressor blades, vanes, IGV, rotors, stators. joe.walker@storkhe.com