Possible bug in determining turbine type

[luwang00]

Bug description
The section below on determining the type of the turbine looks incorrect. It might be caused by problems with merging.

• The branches for MHK are duplicated.
• The use of SubDyn no longer indicates fixed turbines because SubDyn can now be used to model floating substructures.

openfast/modules/openfast-library/src/FAST_Subs.f90

Lines 1869 to 1890 in 7e8be52

	! determine what kind of turbine we're modeling:
	IF ( p%MHK == 1 ) THEN
	p%TurbineType = Type_MHK_Fixed
	ELSEIF ( p%MHK == 2 ) THEN
	p%TurbineType = Type_MHK_Floating
	ELSEIF ( p%CompHydro == Module_HD ) THEN
	IF ( p%CompSub == Module_SD ) THEN
	p%TurbineType = Type_Offshore_Fixed
	ELSE
	p%TurbineType = Type_Offshore_Floating
	END IF
	ELSEIF ( p%CompMooring == Module_Orca ) THEN
	p%TurbineType = Type_Offshore_Floating
	ELSEIF ( p%CompSub == Module_ExtPtfm ) THEN
	p%TurbineType = Type_Offshore_Fixed
	ELSEIF ( p%MHK == 1 ) THEN
	p%TurbineType = Type_MHK_Fixed
	ELSEIF ( p%MHK == 2 ) THEN
	p%TurbineType = Type_MHK_Floating
	ELSE
	p%TurbineType = Type_LandBased
	END IF

OpenFAST Version
This code section is from the dev branch to be released as v4.0.0.

Additional context
It is not clear whether this issue has any impact on the results.

[luwang00]

Hi @hkross and @bjonkman, please take a look at this if you have time. Thanks!

[hkross]

Hi @luwang00, I am not sure why the MHK calls are repeated. Those should only need to be in there once. I think having them at the beginning would work. If MHK=1, it is a fixed MHK turbine, else if MHK=2, it is a floating MHK turbine, else it is a wind turbine. I'm not sure about determining the offshore wind turbine type and will let others comment on that.

[bjonkman]

I think this is a result of a merge problem.

I had simplified the logic here (0ea4605), removing those last two checks in the IF statement:

but the last two lines are somehow still coming from Hannah's original code, so they must have been added again with a later merge (9c7c4bb)

I remember having a conversation with Jason about how to determine floating/fixed-bottom with SubDyn because this logic didn't get changed when OpenFAST added capability to model floating systems with SubDyn. It seemed complicated, so I decided not to mess with it until I needed to add it to my own code. I don't think this is super critical, though. These are the instances where I see this variable used in OpenFAST:

• a check that floating systems have a non-negative TowerBsHt in ElastoDyn,
• a check that AD14 doesn't use its tower influence model for floating systems (that model assumes the tower doesn't move from its initial position),
• a check that offshore fixed and floating turbines use TurbinePos(3)=0 (I think this is for FAST.Farm),
• printing to the OpenFAST summary file

[andrew-platt]

Completed in 4.0.0 (#2586)