QTF input format for OpenFAST

Dear All,

I am interested in obtaining the second-order forces for a semisubmersible floating platform using OpenFAST v2.4.0. I used ANSYS AQWA to obtain the full QTF sum/difference matrices and converted them to WAMIT (.12d/s) format using a python script. I understand that the WAMIT output file (.12d/s) contains only upper half diagonal matrix. Can I use the full matrix or is it mandatory to use only half matrix with OpenFAST?


Dear Ramya,

Section 6.8.4 of the draft HydroDyn User’s Guide and Theory Manual (drive.google.com/file/d/11WY1LR … sp=sharing) provides the answer:

Best regards,