#1 2018-01-23 21:14:42

seenu
Member
Registered: 2017-12-22
Posts: 19

AEP & dRIX

For an island that we are exploring, the dRIX is very high, due to mountainous terrain with steep slopes. There is however relatively flat land to the center-left of this island. Would you recommend a way to explore the potential to install wind turbines in the flat areas?

We attempted to focus the grid only on this flat surfaces, but yet recorded high dRIX. Why is that?

Last edited by seenu (2018-01-23 21:15:00)

Offline

#2 2018-01-24 10:48:39

Morten
Administrator
From: DTU Wind Energy
Registered: 2009-11-02
Posts: 129
Website

Re: AEP & dRIX

Hi Seenu,


The ruggedness index (RIX) is a measure of the terrain complexity in the area around a site. Delta-RIX (dRIX) is the difference between the RIX numbers at the site of interest and at the reference mast. Terrain complexity leads to uncertainty in linearized flow models, such as the one used in WAsP. But errors related to generalization of the wind climate at reference mast data and errors related to climate prediction at the site of interest will often compensate each other when dRIX is close to zero, i.e. when the RIX numbers for the two sites are comparable. A positive dRIX value means that the terrain around the site of interest is more complex than near the reference mast and the model is likely to over-predicted the wind speed. Best practice is to install a reference mast at the site of interest, let it measure for 2-3 years, and use the local data for the wind resource estimate. You could also try the WAsP CFD model, which generally gives better predictions in complex terrain than the default flow model in WAsP.


Best regards,
Morten

Offline

#3 2018-05-09 19:56:13

seenu
Member
Registered: 2017-12-22
Posts: 19

Re: AEP & dRIX

Thank you.

Offline

#4 2018-05-12 20:38:32

ysga
Member
Registered: 2017-08-29
Posts: 14

Re: AEP & dRIX

Morten wrote:

Hi Seenu,


The ruggedness index (RIX) is a measure of the terrain complexity in the area around a site. Delta-RIX (dRIX) is the difference between the RIX numbers at the site of interest and at the reference mast. Terrain complexity leads to uncertainty in linearized flow models, such as the one used in WAsP. But errors related to generalization of the wind climate at reference mast data and errors related to climate prediction at the site of interest will often compensate each other when dRIX is close to zero, i.e. when the RIX numbers for the two sites are comparable. A positive dRIX value means that the terrain around the site of interest is more complex than near the reference mast and the model is likely to over-predicted the wind speed. Best practice is to install a reference mast at the site of interest, let it measure for 2-3 years, and use the local data for the wind resource estimate. You could also try the WAsP CFD model, which generally gives better predictions in complex terrain than the default flow model in WAsP.


Best regards,
Morten

Dear Morten.

Is WAsP CFD model free (I have educational license)? Can I use it too?

Offline

#5 2018-05-13 22:11:29

Morten
Administrator
From: DTU Wind Energy
Registered: 2009-11-02
Posts: 129
Website

Re: AEP & dRIX

WAsP CFD is not free. However, if you are a student at DTU then please ask your supervisor to contact the WAsP group about your needs.

Offline

#6 2018-05-14 16:32:01

seenu
Member
Registered: 2017-12-22
Posts: 19

Re: AEP & dRIX

Morten wrote:

WAsP CFD is not free. However, if you are a student at DTU then please ask your supervisor to contact the WAsP group about your needs.


Does not WAsP student Package has two free simulation?

Offline

#7 2018-05-15 10:19:13

ysga
Member
Registered: 2017-08-29
Posts: 14

Re: AEP & dRIX

Morten wrote:

WAsP CFD is not free. However, if you are a student at DTU then please ask your supervisor to contact the WAsP group about your needs.

Unfortunately, I am not DTU student.

It means that, I can not use it as far as I understand.

Last edited by ysga (2018-05-15 15:27:42)

Offline

Board footer

Powered by FluxBB