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Ansys Learning Forum › Forums › Discuss Simulation › Fluids › Connection Stiffness Ansys AQWA › Reply To: Connection Stiffness Ansys AQWA

May 9, 2024 at 9:37 am
S.S.S.ShankaVasuki
Subscriber

Thank you. I have incorporated all of your suggestions and now I have also increased the number of blocks from 4 to 16 to get better results and the results are shown in the plot below.

Based on this I have some questions:

  1. The red line refers to my simulation and the grey line refers to the research paper. Each dot on the red line represents the heave RAO of a single block at CoG. The response matches well until 250m which refers to the 14th block. But the response of the 15th and the 16th block (the last two blocks) are not matching well. The response of these two blocks reduces even further. I have tried all possible changes but no changes in the results. Could you suggest some causes for this difference and on how I can correct this?
  2. Also the values of the Heave RAOs have been taken from the hydrodynamic response - Time domain analysis with regular waves of amplitude 0.5m and frequency of 0.7rad/s. The question I have is - in the solution section of HR analysis, there is an option to plot RAO-Based Response for all 6DoF (my focus is just Heave RAO). Once I plot these for all the 16 bodies, I get the maximum and minimum values of each body as shown in the image below where each line refers to a block (I have taken only the maximum values in the plot shown above). So, I wanted to know whether these values are indeed RAOs as their units are in [m] or should I divide these values by the amplitude of the wave? 

Please let me know what changes I can make to get better match with the paper.

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