Wrong argument passed to `FAST_InitializeAll_T`

[marchdf]

Bug description

The definition of the function FAST_InitializeAll_T has TurbId as it's second argument. The call sites: https://github.com/OpenFAST/openfast/blob/main/modules/openfast-library/src/FAST_Library.f90#L144 and https://github.com/OpenFAST/openfast/blob/main/modules/openfast-library/src/FAST_Library.f90#L148 pass in iTurb to that argument and not TurbId.

To Reproduce
I am calling openfast from amr-wind but this isn't specific to that and I don't build stand-alone openfast so I am not sure what the steps are to reproduce.

Expected behavior
I would expect TurbId to be passed to FAST_InitializeAll_T and not iTurb since that is what it expects in the argument list.

OpenFAST Version
3.5.2

System Information (please complete the following information):

• OS: NAME="Rocky Linux" VERSION="8.9 (Green Obsidian)" ID="rocky" ID_LIKE="rhel centos fedora" VERSION_ID="8.9"
• Compiler: GNU Fortran (Spack GCC) 10.4.0

[andrew-platt]

The problem appears to be due to a discrepency in how the TurbId is used in FAST.Farm vs with AMR-Wind. When used with FAST.Farm, the turbine id ranges from 1:NumTurbines, but when coupled to a C code, the turbine id ranges from 0:NumTurbines-1.

[andrew-platt]

Looking at the code, the FAST_Sizes routine does not have a variable TurbID. Are you referring to another call to FAST_InitializeAll_T from the FAST_OpFM_Init routine (https://github.com/OpenFAST/openfast/blob/main/modules/openfast-library/src/FAST_Library.f90#L589)?

For reasons completely unknown to me, the FAST_OpFM_Initroutine contains both TurbID and iTurb in its input argument list. I don't actually know why both arguments are there, or if they would ever be different. However the use of iTurb appears to be consistent in this routine -- it must match the index of the Turbine data structure getting passed to FAST_InitializeAll_T and all uses of the Turbine data structure that follows. So I propose we remove either TurbID or iTurb from the argument list in FAST_OpFM_Init as those appear redundant.

[marchdf]

I am referring to this FAST_InitializeAll_T: https://github.com/OpenFAST/openfast/blob/main/modules/openfast-library/src/FAST_Subs.f90#L37. It uses TurbId in the argument list.

I don't know why there are 2 IDs being passed into FAST_OpFM_Init. In AMR-Wind we seem to pass a local and a global ID to those arguments: https://github.com/Exawind/amr-wind/blob/main/amr-wind/wind_energy/actuator/turbine/fast/FastIface.cpp#L224. I don't know why. Maybe @gantech or @psakievich have a historical perspective on this?

[bjonkman]

Originally, Turbine was not an array, but there was a TurbID for file naming purposes. The iTurb variable was introduced in #20

[andrew-platt]

I'm going to close this issue in deference to the underlying issue outlined in #2096.