AeroAcoustics module verification: Missing turbine model

[edaniele-tpi]

I would like to reproduce the verification case for the AeroAcoustics module as described here.
Unfortunately I cannot find the corresponding turbine model input, i.e. the IEA-3.4-130-RWT, neither within the regression tests, nor at the IEA task repo.
Can anybody point me out to the OpenFAST model for such a verification?
Thanks in advance for your support!

[ptrbortolotti]

Hello,
you should be able to find the model here https://github.com/OpenFAST/r-test/tree/main/glue-codes/openfast/IEA_LB_RWT-AeroAcoustics
Let us know if you need anything else.
Best regards,
Pietro Bortolotti

[edaniele-tpi]

Hi again @ptrbortolotti ,

I am writing again for a related issue I faced while running a similar test on an internal model.
Apparently, by switching the BLMod entry of the AeroAcoustics input file to 2 (Pretabulated), the simulation stops, without any error or warning message, as soon as the start of the aero-acoustic analysis is encountered (see AAStart).
Clearly, I don't face this issue with the model of the IEA37-3.4RWT in here, but I do experience it even if I include the boundary layer data of the IEA37-3.4RWT into my internal model, thus, I exclude gross non conformities in terms of input file format.
I wonder, if you have any educated guess about this strange behavior, or you can help me debugging the hidden conflict (?).
Thanks in advance for your kind support.
Best regards,

Elia

[ptrbortolotti]

Hello Elia,
I'm sorry to read that things don't run properly. A couple clarifications: is the code stopping or hanging? In the past the code seemed to hang, but it was just really really slow because of an excessive number of observers. And is the code not working only when switching BLMod (https://github.com/OpenFAST/r-test/blob/78d763effae41fb41ecff5143f0b486a6ac0593c/glue-codes/openfast/IEA_LB_RWT-AeroAcoustics/AeroAcousticsInput.dat#L14) to 2? What model are you loading for TBL-TE noise (https://github.com/OpenFAST/r-test/blob/78d763effae41fb41ecff5143f0b486a6ac0593c/glue-codes/openfast/IEA_LB_RWT-AeroAcoustics/AeroAcousticsInput.dat#L13)?
Best regards,
Pietro

[edaniele-tpi]

Hi Pietro,

thanks for getting back to this thread.
Indeed the code stops, and exits normally, without producing the expected output, and lacking of any warnings or error message.

To clarify again a few aspects: I tested the code by means of the IEA37-3.4RWT case by changing all possible parameters within the AeroAcousticsInput.dat, without encountering any issues. I do experienced some slowly running cases, especially when turning on the TNO mode for the TBLTEMod switch.

The problem arises with an internal turbine model, that runs just smooth except for the case BLMod=2. In this case the TBLTEMod is set on BPM. So, the question is, what can be possibly wrong with the boundary layer input file? Anything I can double check in terms of format, or critical entries?

Thanks in advance for your feedback.

Best regards,

Elia

[ptrbortolotti]

Hello Elia,
It's somewhat hard for me to guess what's wrong with those files without being able to access them. Also, I was not the original developer of that code. I only cleaned, imported, and verified/tested.
This said, I find surprising that the model does not run even by calling the BL files from the IEA3.4 example. To debug this, I would build some Frankenstein turbine mixing and matching your model with the IEA3.4, until you are able to isolate the issue. I would start from the IEA3.4 that runs, and slowly import your new files. For example, is the IEA3.4 model running if you call your new BL files? If yes, then the problem must be elsewhere. If not, I would call a single BL file across all stations and carefully go through it.
Again, I'm sorry that this is not working as robustly as it should. Thank you for debugging this.
Best regards,
Pietro

PS: Note that in the validation study described in https://www.nrel.gov/docs/fy21osti/79664.pdf we used BLMod=1 and TBLTEMod=1. These were the models that we verified within IEA Wind Task 39 (https://iea-wind.org/wp-content/uploads/2021/05/report_WTNCBenchmark.pdf) and that we fully trust in terms of implementation

[edaniele-tpi]

Hi Pietro,

thanks for getting back. Just to be clear one again: The provided verification case for the IEA3.4 is perfectly fine, and works like a charm with all possible combination of aero-acoustic input parameters.

This said, I tried to change the BL data for all section straightaway, by pointing to a single dummy file, attached
AF_BL_39.zip. Clearly, I had to rename the corresponding line within the polar data files.

When I do this for all sections, form root to tip, the code exit without running a single second, providing no warning or error whatsoever, see the terminal here:

**************************************************************************************************
OpenFAST

Copyright (C) 2021 National Renewable Energy Laboratory
Copyright (C) 2021 Envision Energy USA LTD

This program is licensed under Apache License Version 2.0 and comes with ABSOLUTELY NO WARRANTY.
See the "LICENSE" file distributed with this software for details.
**************************************************************************************************

OpenFAST-v3.0.0
Compile Info:
 - Compiler: Intel(R) Fortran Compiler 1900
 - Architecture: 64 bit
 - Precision: single
 - OpenMP: No
 - Date: Jun 23 2021
 - Time: 21:25:05
Execution Info:
 - Date: 02/17/2022
 - Time: 09:37:29+0100

OpenFAST input file heading:
    IEA task 37 RWT turbine -- https://github.com/IEAWindTask37/IEA-3.4-130-RWT

Running ElastoDyn.
Nodal outputs section of ElastoDyn input file not found or improperly formatted.
Running AeroDyn.
AD15 Nodal Outputs: Nodal output section of AeroDyn input file not found or improperly formatted.
Skipping nodal outputs.
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 1, blade 1)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 1)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 1, blade 2)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 2)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 1, blade 3)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 3)
Running AeroAcoustics (v1.00.00, 18-Aug-2016).
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
Running InflowWind.
 Time: 0 of 20 seconds.

But, if I skipped the very first section, it runs smoothly, as demonstrated here, noticing the different first entry AeroAcoustics_IO: :

**************************************************************************************************
OpenFAST

Copyright (C) 2021 National Renewable Energy Laboratory
Copyright (C) 2021 Envision Energy USA LTD

This program is licensed under Apache License Version 2.0 and comes with ABSOLUTELY NO WARRANTY.
See the "LICENSE" file distributed with this software for details.
**************************************************************************************************

OpenFAST-v3.0.0
Compile Info:
 - Compiler: Intel(R) Fortran Compiler 1900
 - Architecture: 64 bit
 - Precision: single
 - OpenMP: No
 - Date: Jun 23 2021
 - Time: 21:25:05
Execution Info:
 - Date: 02/17/2022
 - Time: 09:37:54+0100

OpenFAST input file heading:
    IEA task 37 RWT turbine -- https://github.com/IEAWindTask37/IEA-3.4-130-RWT

Running ElastoDyn.
Nodal outputs section of ElastoDyn input file not found or improperly formatted.
Running AeroDyn.
AD15 Nodal Outputs: Nodal output section of AeroDyn input file not found or improperly formatted.
Skipping nodal outputs.
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 1, blade 1)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 1)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 1, blade 2)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 2)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 1, blade 3)
Warning: Turning off Unsteady Aerodynamics because C_nalpha is 0. (node 2, blade 3)
Running AeroAcoustics (v1.00.00, 18-Aug-2016).
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF00_BL.txt
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
 AeroAcoustics_IO: reading BL table:.\Airfoils/AF_BL_39.dat
Running InflowWind.


 Total Real Time:       7.881 seconds
 Total CPU Time:        7.8281 seconds
 Simulation CPU Time:   7.4844 seconds
 Simulated Time:        20 seconds
 Time Ratio (Sim/CPU):  2.6722

 OpenFAST terminated normally.

Thus, I may conclude, that there is no issue with format of the BL data I exchanged into the case. Even if my dummy BL data have surely a not always matching TE features, with what given via the coordinates' files.

It is worth noticing, that the BL data of the first section provided with the IEA3.4 case are identically zeros. It may be a simplification since these are not used in the analysis because of the BldPrcnt entry set to 70% of the span. However this may not correspond to the reality: A circle is certainly aerodynamically poor, but it still has a BL ;-)

Could you comment on this?
In the meanwhile I will try changing the polar data as well in it.

[ptrbortolotti]

Also, have you seen this python script? https://github.com/OpenFAST/python-toolbox/blob/dev/pyFAST/aeroacoustics/write_BLfiles.py

[edaniele-tpi]

Sure, but since we employ an internal flavor of xfoil I need to convert BL data somehow differently. Output file format is nevertheless the same, and luckily working ;-)

[edaniele-tpi]

Hi @ptrbortolotti ,

I managed to compile code on WSL under Windows and dig a bit more into the possible reasons for the above mentioned unexpected behavior.
Allegedly the problem arises from the subroutine BL_Param_Interp within the AeroAcoustics module: Here the code does not throw the foreseen error concerning the Reynolds number being outside the given values as table sets. Moreover, the code accepts merely a fix size for the Reynolds number based boundary layer data table number, i.e. for all the blade sections.

I thus include a check for a single Reynolds number table case, with a related simplified interpolation, and I got rid of the issue. In case you are interested in this adjustment here is the snippet for the DO loop in the subroutine BL_Param_Interp within the AeroAcoustics module:

! special treatment for single Reynolds number table available.
  IF (size(p%ReListBL) .eq. 1) THEN
    re_flag = .TRUE.
    DO loop2=1,size(p%AOAListBL)-1
        IF (  (AlphaNoise.le.p%AOAListBL(loop2+1)) &
            .and. (AlphaNoise.gt.p%AOAListBL(loop2))  ) THEN
            aoadif1=abs(AlphaNoise-p%AOAListBL(loop2+1))
            aoadif2=abs(AlphaNoise-p%AOAListBL(loop2))

            xx1= p%dstarall1(loop2,1,whichairfoil)
            xx2= p%dstarall1(loop2+1,1,whichairfoil)
            m%dstarVar(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            xx1= p%dstarall2(loop2,1,whichairfoil)
            xx2= p%dstarall2(loop2+1,1,whichairfoil)
            m%dstarVar(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            xx1= p%d99all1(loop2,1,whichairfoil)
            xx2= p%d99all1(loop2+1,1,whichairfoil)
            m%d99Var(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            xx1= p%d99all2(loop2,1,whichairfoil)
            xx2= p%d99all2(loop2+1,1,whichairfoil)
            m%d99Var(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            xx1= p%Cfall1(loop2,1,whichairfoil)
            xx2= p%Cfall1(loop2+1,1,whichairfoil)
            m%CfVar(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            xx1= p%Cfall2(loop2,1,whichairfoil)
            xx2= p%Cfall2(loop2+1,1,whichairfoil)
            m%CfVar(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            xx1= p%EdgeVelRat1(loop2,1,whichairfoil)
            xx2= p%EdgeVelRat1(loop2+1,1,whichairfoil)
            m%EdgeVelVar(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            xx1= p%EdgeVelRat2(loop2,1,whichairfoil)
            xx2= p%EdgeVelRat2(loop2+1,1,whichairfoil)
            m%EdgeVelVar(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

            RETURN ! We exit the routine !
        ENDIF
        IF (loop2 .eq. (size(p%AOAListBL)-1) ) THEN
            IF (AlphaNoise .gt. p%AOAListBL(size(p%AOAListBL))) THEN
                print*, 'Warning AeroAcoustics Module - Angle of attack (AoA) range is not in the range provided by the user'
                print*, 'Station ',whichairfoil
                print*, 'Airfoil AoA ', AlphaNoise,' Using the closest AoA ', &
                    p%AOAListBL(loop2+1)
                m%dStarVar  (1) = p%dstarall1  (loop2+1,1,whichairfoil)
                m%dStarVar  (2) = p%dstarall2  (loop2+1,1,whichairfoil)
                m%d99Var    (1) = p%d99all1    (loop2+1,1,whichairfoil)
                m%d99Var    (2) = p%d99all2    (loop2+1,1,whichairfoil)
                m%CfVar     (1) = p%Cfall1     (loop2+1,1,whichairfoil)
                m%CfVar     (2) = p%Cfall2     (loop2+1,1,whichairfoil)
                m%EdgeVelVar(1) = p%EdgeVelRat1(loop2+1,1,whichairfoil)
                m%EdgeVelVar(2) = p%EdgeVelRat2(loop2+1,1,whichairfoil)
            ELSEIF (AlphaNoise .lt. p%AOAListBL(1)) THEN
                print*, 'Warning AeroAcoustics Module - Angle of attack (AoA) range is not in the range provided by the user'
                print*, 'Station ',whichairfoil
                print*, 'Airfoil AoA ',AlphaNoise,' Using the closest AoA ', &
                    p%AOAListBL(1)
                m%dStarVar(1)   = p%dstarall1  (1,1,whichairfoil)
                m%dStarVar(2)   = p%dstarall2  (1,1,whichairfoil)
                m%d99Var(1)     = p%d99all1    (1,1,whichairfoil)
                m%d99Var(2)     = p%d99all2    (1,1,whichairfoil)
                m%CfVar(1)      = p%Cfall1     (1,1,whichairfoil)
                m%CfVar(2)      = p%Cfall2     (1,1,whichairfoil)
                m%EdgeVelVar(1) = p%EdgeVelRat1(1,1,whichairfoil)
                m%EdgeVelVar(2) = p%EdgeVelRat2(1,1,whichairfoil)
            ENDIF
        ENDIF
    ENDDO
  ELSE
    !
    DO loop1=1,size(p%ReListBL)-1
    !   print*, "Debug - Reynolds table no. ", loop1
      IF (   (RC.le.p%ReListBL(loop1+1)) .and. (RC.gt.p%ReListBL(loop1))  ) THEN
        !   print*, "Debug - Reynolds between tables"
          re_flag = .TRUE.
          redif1=abs(RC-p%ReListBL(loop1+1))
          redif2=abs(RC-p%ReListBL(loop1))
          DO loop2=1,size(p%AOAListBL)-1

              IF (  (AlphaNoise.le.p%AOAListBL(loop2+1)) .and. (AlphaNoise.gt.p%AOAListBL(loop2))  ) THEN
                  aoadif1=abs(AlphaNoise-p%AOAListBL(loop2+1))
                  aoadif2=abs(AlphaNoise-p%AOAListBL(loop2))

                  xx1=( p%dstarall1(loop2,loop1+1,whichairfoil)*redif2+p%dstarall1(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%dstarall1(loop2+1,loop1+1,whichairfoil)*redif2+p%dstarall1(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%dstarVar(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  xx1=( p%dstarall2(loop2,loop1+1,whichairfoil)*redif2+p%dstarall2(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%dstarall2(loop2+1,loop1+1,whichairfoil)*redif2+p%dstarall2(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%dstarVar(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  xx1=( p%d99all1(loop2,loop1+1,whichairfoil)*redif2+p%d99all1(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%d99all1(loop2+1,loop1+1,whichairfoil)*redif2+p%d99all1(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%d99Var(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  xx1=( p%d99all2(loop2,loop1+1,whichairfoil)*redif2+p%d99all2(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%d99all2(loop2+1,loop1+1,whichairfoil)*redif2+p%d99all2(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%d99Var(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  xx1=( p%Cfall1(loop2,loop1+1,whichairfoil)*redif2+p%Cfall1(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%Cfall1(loop2+1,loop1+1,whichairfoil)*redif2+p%Cfall1(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%CfVar(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  xx1=( p%Cfall2(loop2,loop1+1,whichairfoil)*redif2+p%Cfall2(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%Cfall2(loop2+1,loop1+1,whichairfoil)*redif2+p%Cfall2(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%CfVar(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  xx1=( p%EdgeVelRat1(loop2,loop1+1,whichairfoil)*redif2+p%EdgeVelRat1(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%EdgeVelRat1(loop2+1,loop1+1,whichairfoil)*redif2+p%EdgeVelRat1(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%EdgeVelVar(1)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  xx1=( p%EdgeVelRat2(loop2,loop1+1,whichairfoil)*redif2+p%EdgeVelRat2(loop2,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  xx2=( p%EdgeVelRat2(loop2+1,loop1+1,whichairfoil)*redif2+p%EdgeVelRat2(loop2+1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  m%EdgeVelVar(2)=(xx1*aoadif1+xx2*aoadif2) / (aoadif1+aoadif2)

                  RETURN ! We exit the routine !
              ENDIF
              IF (loop2 .eq. (size(p%AOAListBL)-1) ) THEN

                  IF (AlphaNoise .gt. p%AOAListBL(size(p%AOAListBL))) THEN
                      print*, 'Warning AeroAcoustics Module - Angle of attack (AoA) range is not in the range provided by the user'
                      print*, 'Station ',whichairfoil
                      print*, 'Airfoil AoA ',AlphaNoise,' Using the closest AoA ',p%AOAListBL(loop2+1)
                      m%dStarVar  (1) = ( p%dstarall1  (loop2+1,loop1+1,whichairfoil)*redif2 + p%dstarall1  (loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                      m%dStarVar  (2) = ( p%dstarall2  (loop2+1,loop1+1,whichairfoil)*redif2 + p%dstarall2  (loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                      m%d99Var    (1) = ( p%d99all1    (loop2+1,loop1+1,whichairfoil)*redif2 + p%d99all1    (loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                      m%d99Var    (2) = ( p%d99all2    (loop2+1,loop1+1,whichairfoil)*redif2 + p%d99all2    (loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                      m%CfVar     (1) = ( p%Cfall1     (loop2+1,loop1+1,whichairfoil)*redif2 + p%Cfall1     (loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                      m%CfVar     (2) = ( p%Cfall2     (loop2+1,loop1+1,whichairfoil)*redif2 + p%Cfall2     (loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                      m%EdgeVelVar(1) = ( p%EdgeVelRat1(loop2+1,loop1+1,whichairfoil)*redif2 + p%EdgeVelRat1(loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                      m%EdgeVelVar(2) = ( p%EdgeVelRat2(loop2+1,loop1+1,whichairfoil)*redif2 + p%EdgeVelRat2(loop2+1,loop1,whichairfoil)*redif1 )/(redif1+redif2)
                  ELSEIF (AlphaNoise .lt. p%AOAListBL(1)) THEN
                      print*, 'Warning AeroAcoustics Module - Angle of attack (AoA) range is not in the range provided by the user'
                      print*, 'Station ',whichairfoil
                      print*, 'Airfoil AoA ',AlphaNoise,' Using the closest AoA ',p%AOAListBL(1)
                      m%dStarVar(1)   = ( p%dstarall1  (1,loop1+1,whichairfoil)*redif2 + p%dstarall1  (1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                      m%dStarVar(2)   = ( p%dstarall2  (1,loop1+1,whichairfoil)*redif2 + p%dstarall2  (1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                      m%d99Var(1)     = ( p%d99all1    (1,loop1+1,whichairfoil)*redif2 + p%d99all1    (1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                      m%d99Var(2)     = ( p%d99all2    (1,loop1+1,whichairfoil)*redif2 + p%d99all2    (1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                      m%CfVar(1)      = ( p%Cfall1     (1,loop1+1,whichairfoil)*redif2 + p%Cfall1     (1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                      m%CfVar(2)      = ( p%Cfall2     (1,loop1+1,whichairfoil)*redif2 + p%Cfall2     (1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                      m%EdgeVelVar(1) = ( p%EdgeVelRat1(1,loop1+1,whichairfoil)*redif2 + p%EdgeVelRat1(1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                      m%EdgeVelVar(2) = ( p%EdgeVelRat2(1,loop1+1,whichairfoil)*redif2 + p%EdgeVelRat2(1,loop1,whichairfoil)*redif1 ) / (redif1+redif2)
                  ENDIF
              ENDIF
          ENDDO
      ENDIF    
    ENDDO 
  ENDIF

Maybe you can consider this for a next release.

Best regards,

Elia

[ptrbortolotti]

Hello Elia,
thank you for the debugging. Would you be able to submit a pull request? This would give you the right credit for the bug fix. I greatly appreciate your efforts here.
Thanks,
Pietro