## TwrBsMxt is where

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Masataka.Motoyama
Posts: 5
Joined: Fri Jul 05, 2019 6:45 pm
Organization: kyushu university
Location: Japan

### TwrBsMxt is where

Hi all, I am new bee in this forum. I'd like to know Where I can find ,for example TwrBsMxt, from the FAST code?
In the ADTwr_CalcOutput() we can get the value of y%TowerLoad%moment(:,j). but the value seems not corresponding TwrBsMxt.
How can I calculate TwrBsMxt? please let me know of it

-------------------------
kyushu univ
postdoc
masataka motoyama

Masataka.Motoyama
Posts: 5
Joined: Fri Jul 05, 2019 6:45 pm
Organization: kyushu university
Location: Japan

### Re: TwrBsMxt is where

Dear Jason

please let me know How to derive the TwrBsMxt from the FAST code.

best regards.

masataka motoyama

Jason.Jonkman
Posts: 4224
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

### Re: TwrBsMxt is where

Dear Masataka,

Are you asking where in the FAST source code ElastoDyn output TwrBsMxt is calculated? This is in source file ElastoDyn.f90/ED_CalcOutput().

Or you are asking what the equation is for calculating ElastoDyn output TwrBsMxt? The tower base moments from ElastoDyn are calculated by integrating along the tower, blades, and nacelle the applied aerodynamic pitching moments + ( radial vector ) x ( applied aerodynamic forces + gravitation forces - inertia forces ).

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Masataka.Motoyama
Posts: 5
Joined: Fri Jul 05, 2019 6:45 pm
Organization: kyushu university
Location: Japan

### Re: TwrBsMxt is where

Dear jason

I mean both.
so, you mean TwrBsMxt consists of not only aerodynamic pitching moments , but also another elements?
OK. I will check ElastoDyn.f90/ED_CalcOutput().

best regards.

masataka

Jason.Jonkman
Posts: 4224
Joined: Thu Nov 03, 2005 4:38 pm
Location: Boulder, CO
Contact:

### Re: TwrBsMxt is where

Dear Masataka,

Correct. The tower-base load outputs from ElastoDyn not only include aerodynamic applied loads, but also gravitational and inertial effects. The tower-base load outputs from ElastoDyn are the reaction loads applied from the tower to the platform.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov