Data about NREL Horizontal-Axis Tidal Current Turbine

Wind & Water Tidal Current
1

Dear all,

I am currently studying on tidal turbine wakes in the frame of my master thesis and I am using the NREL-developed software SOWFA.
Now that I am getting more and more familiar with it thanks to the tutorials, I would like to begin to customize it to fit my aims.
However, I cannot find any tidal aerodynamic blade data publicly available, with which I could change the blade inputs (i.e. airfoils Cl and Cd vs alpha, airfoil distribution vs radius, etc…).
I did stumble upon a NREL paper entitled "Structural Design of a Horizontal-Axis Tidal Current Turbine Composite Blade " by G.S. Bir, M.J. Lawson and Y.Li in which a tidal turbine is designed.
As a consequence, I was wondering if you were willing to publish the blade data which are needed to run SOWFA.

Thanks in advance,

Regards,

Bruno.

2

Hi Bruno,

The HARP-Opt (dropbox.com/s/xy0if1iyp82p8 … mDanny.zip. If you are not familiar with HARP-Opt, it is a MATLAB based blade design tool.

The HARP-Opt files should contain all the airfoil data you need to run SOFA. Let me know if you have any further questions.

Cheers,

-Mike

3

Hi Mike,

First of all, thanks a lot for your quick answer.
While browsing the airfoil files, I noticed that Cl and Cd were computed for Reynolds numbers between 2 and 14 millions.
I was wondering if for hydro-turbines simulations you were using the highest Reynolds number data by default (i.e. 14 millions), as Re should be around 5 10^7 or if you were using an other set of data.

Thanks in advance,

Regards,

Bruno

4

For the turbine described in the paper you referenced the Re number is between about 2 and 8 million.

For the turbine the Re ~ 2piradiuschordRPM/60 / viscosity. Note that the oncoming flow component of velocity is not significant.

Viscosity for salt water is ~1e-6

Does that clear it up?

5

Hi Mike,

It does clear this up. Thanks a lot for your input.

Regards,

Bruno

6

Hi Mike,

I have now implemented the tidal turbine with SOWFA and it works well when I force rotational speed and pitch. However, I would like to know the consequence of a turbine downstream flow on a turbine located behind. In order to do that, I need to tune the torque and pitch controllers provided with SOWFA. However, I haven’t been able to find the correct values yet, and I was wondering if you had already designed these controllers values for this turbine. Moreover, could you tell me where I can find a detailed description of the controllers?

Thanks in advance,

Regards,

Bruno.

7

Hi Bruno,

As far as I know, there was no controller specified for the Reference Model 1 tidal turbine, probably a good place to start is copy from NREL 5MW wind turbine example, as these are both variable-speed variable-pitch variable-yaw turbines. There are some recent files available on GitHub [url]https://github.com/nnmrec/fastFlume[/url] related to modeling this turbine with SOWFA, but a controller has not yet been implemented. If you find any good resources, or make some progress on this I’d be happy to know! Thanks, and best success with your thesis research.

Thanks,
Danny