Aeroacoustics in fast v7

Hello

I would like to use fast to predict noise in designed by me wind turbine. I follow the instructions in user guide fo fast as well as in the “Semi-Empirical Aeroacoustic Noise Prediction Code for Wind Turbines”.
I get an error given below. I tried to implement nosie prediction code to one of the test cases and i did get the same error. Fast works for test subjects without noise prediction enabled.

I cannot attach the snapshot of this error so i will write it down below.
Error in command prompt:

Running NWTC Subroutine Library <v1.07.00b-mlb, 10-Jan-2013>.
forrtl:severe<64>:input conversion error, unit 20, file C:\Users\Desktop\fastv7\CertTest\Noise.ipt
Image PC Routine Line Source
FAST.exe 0063F060 Unknown Unknown Unknown

Best regards
Robert Nowak

Hi, Robert.

It sounds like your Noise.ipt file has a line that isn’t in the format that the compiled code expects. I know at one point there was some issue with the Noise.ipt file in the CertTest folder as well… I don’t recall the details, but I think maybe it was mixing up integers and logicals. Some older compilers let you read T/F and convert it to an integer and read integers that got converted to T/F. The flags in the noise input file should be entered as integers; the “rounded tip” is a logical (should be entered as “true” or “false” without the quotation marks).

It’s been quite a while since I’ve run FAST v7, but I’d first try to set the “Echo” flag in the primary FAST input file to “true” and run it to see which line is the problem (look at the last line in the .echo file that gets generated). If that doesn’t work, you could post your Noise.ipt file here and I can take a look at it.

Hello

Sorry for replying late.
I tried to fix Noise.ipt file but couldn’t find any wrong data. I read the Echo file and there wasn’t any informaton about Noise.ipt or aeroacoustics in general.
Below i paste my Noise.ipt file:

[code]Input file for aeroacoustic code

344.05 C0 SPEED OF SOUND METERS/SEC
1.0 ALPRAT TIP SPANWISE LIFT CURVE SLOPE (Default = 1.0) —
TRUE ROUND LOGICAL INDICATING ROUNDED TIP —

1 IBLUNT FLAG TO COMPUTE BLUNTNESS NOISE —
1 ILAM FLAG TO COMPUTE LBL NOISE —
1 ITIP FLAG TO COMPUTE TIP NOISE —
2 ITRIP FLAG TO TRIP BOUNDARY LAYER (=0 no trip, =1 heavy trip, =2 light trip)
1 ITURB FLAG TO COMPUTE TBLTE NOISE —
1 IInflow FLAG TO COMPUTE Turbulent Inflow NOISE —

1 NoiseOutSwitch Switch to determine which time series of sound pressure level output

50.0001 70.0001 20.00010 (x,y,z) Observer location in tower-base coordinate system (m)

Thickness (m) PSI (deg) Same elements as aerodyn inputs
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5
0.0001 12.5

C Thickness SEGMENT TRAILING EDGE THICKNESS METERS
C PSI SEGMENT BLUNTNESS ANGLE DEGREES
[/code]
Best regards

I don’t immediately see a problem in your input file. I did take a quick look at the Noise source code and it doesn’t look very forgiving if you have anything unexpected in the file.

How many nodes are defined in AeroDyn? If AeroDyn has more nodes than are specified in the Noise input file, I can see that it would crash…

There is the same number of nodes defined in AeroDyn - 44.

I would try to use the Noise.ipt in the FAST v7 archive and add enough lines in the Thickness/PSI table to match the model you are running, just to see if that works. If it does work, try changing it to the values you want to use from your new file, one by one, until it stops working again.

Hello

Thank for your quick replies.
I tried that and still got the same error. I used the NAFNoise program too and got this error as well but I managed to fix it by changing the airfoil file where values were separated by tab insted of space. It looks like it is not the case here. Could you check by yourself if the noise prediction code works in the fast v7? I have bad feeling that something may be wrong with the code not my input files.

Best regards
Robert Nowak

Hi, Robert.

I ran the Noise.ipt file through the debugger and have replicated your problem. The issue is that all but one of the “FLAG TO”… lines should be logicals instead of integers. ITRIP is actually an integer, but the others should be entered as true/false:

true IBLUNT FLAG TO COMPUTE BLUNTNESS NOISE --- true ILAM FLAG TO COMPUTE LBL NOISE --- true ITIP FLAG TO COMPUTE TIP NOISE --- 2 ITRIP SWITCH TO TRIP BOUNDARY LAYER --- true ITURB FLAG TO COMPUTE TBLTE NOISE --- true IInflow FLAG TO COMPUTE Turbulent Inflow NOISE

Hopefully changing those inputs in your file will fix your problem, too.

Thank you very much. Problem solved.

Best regards
Robert Nowak