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QTF
Quote from sun on 11. March 2023, 08:48Hello, Professor David, I want to know how to set it in the platform file to calculate the sum-frequency loads on all potential flow bodies using the full QTF method instead of the Newman approximation method.Is it right to just turn on ‘USE_ DIFF_ FREQS’ and ‘USE_ MEANDRIFT’ is enough?
Hello, Professor David, I want to know how to set it in the platform file to calculate the sum-frequency loads on all potential flow bodies using the full QTF method instead of the Newman approximation method.Is it right to just turn on ‘USE_ DIFF_ FREQS’ and ‘USE_ MEANDRIFT’ is enough?
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Quote from sun on 11. March 2023, 08:53My statement above is wrong: calculate the difference-frequency loads on All potential flow bodies instead of the sum frequency
My statement above is wrong: calculate the difference-frequency loads on All potential flow bodies instead of the sum frequency

Quote from David on 13. March 2023, 20:22Hi Sun,
if you want to explicitly calculate the full QTF you need to set USE_DIFF_FREQS to “true” and both USE_NEWMAN and USE_MEANDRIFT to “false”.
- If USE_MEANDRIFT is “true” only the mean difference forces are calculated, regardless of the settings of the other two variables.
- If USE_NEWMAN is “true” and USE_MEANDRIFT is “false” the Newman approximation is used, regardless of the setting of USE_DIFF_FREQS.
- If USE_DIFF_FREQS is “true” the full QTF is only calculated if both USE_NEWMAN and USE_MEANDRIFT are set to false.
If you have multiple potential flow bodies then you need to assign a POT_DIFF_FILE to each of those bodies. Use POT_DIFF_FILE_2 for the 2nd body, POT_DIFF_FILE_3 for the 3rd and so on…
Best,
David
Hi Sun,
if you want to explicitly calculate the full QTF you need to set USE_DIFF_FREQS to “true” and both USE_NEWMAN and USE_MEANDRIFT to “false”.
- If USE_MEANDRIFT is “true” only the mean difference forces are calculated, regardless of the settings of the other two variables.
- If USE_NEWMAN is “true” and USE_MEANDRIFT is “false” the Newman approximation is used, regardless of the setting of USE_DIFF_FREQS.
- If USE_DIFF_FREQS is “true” the full QTF is only calculated if both USE_NEWMAN and USE_MEANDRIFT are set to false.
If you have multiple potential flow bodies then you need to assign a POT_DIFF_FILE to each of those bodies. Use POT_DIFF_FILE_2 for the 2nd body, POT_DIFF_FILE_3 for the 3rd and so on…
Best,
David
