******************* This email originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list https://spam.ic.ac.uk/SpamConsole/Senders.aspx to disable email stamping for this address. ******************* Dear sir I am a PHD student from Tsinghua Univerity in China. I am writing this letter to enquire some questions about Nektar++ v5.2.0. When the simulation about the VIV of a rigid cylinder are carried out by Nektar++, the Dis_y showed the same value in z direction. However, the Vel_y and Acel_y presented different values in z direction at the same time is quite different. It seems that the Vel_y and Acel_y should be the same value in the z direction for a rigid cylinder. The results are presented as follow. # Time z Disp_x Vel_x Acel_x Disp_y Vel_y Acel_y 400 0 0 0 0 0.00419954 -0.0018539027 -0.0046684539 400 0.19635 0 0 0 0.00419954 -0.0018539026 -0.0046731296 400 0.392699 0 0 0 0.00419954 -0.0018539025 -0.004678392 400 0.589049 0 0 0 0.00419954 -0.0018539025 -0.0046851524 400 0.785398 0 0 0 0.00419954 -0.0018539025 -0.0046888038 400 0.981748 0 0 0 0.00419954 -0.0018539025 -0.004685259 400 1.1781 0 0 0 0.00419954 -0.0018539026 -0.0046771037 400 1.37445 0 0 0 0.00419954 -0.0018539027 -0.00466885 400 1.5708 0 0 0 0.00419954 -0.0018539028 -0.0046617006 400 1.76715 0 0 0 0.00419954 -0.0018539029 -0.004654695 400 1.9635 0 0 0 0.00419954 -0.0018539029 -0.0046481107 400 2.15984 0 0 0 0.00419954 -0.001853903 -0.0046443416 400 2.35619 0 0 0 0.00419954 -0.001853903 -0.0046429716 400 2.55254 0 0 0 0.00419954 -0.0018539029 -0.0046455258 400 2.74889 0 0 0 0.00419954 -0.0018539029 -0.0046517606 400 2.94524 0 0 0 0.00419954 -0.0018539028 -0.0046603436 Thank you for your patient. Best regards.