Learning Forum

[mahdi_r]

Dear all,

I tried to simulate a discharging pipe in a tank with a velocity higher than flutter speed, which causes the pipe to oscillate in the tank. I ran this problem for 2s without problem but when I tried to restart the case at for example 1.9 s with the same time-step (I set the restarting point for fluent and Ansys mechanical exactly at 1.9 s), I got a "(DP 0) Update-Dynamic-Mesh failed. Negative cell volume detected." error.

I appreciate it if someone can help me

[Stephen Orlando]

nWhat changes were made to the setup before the restart? Please be specific and include screenshots.nSteven

[mahdi_r]

nThanks for the reply,nI tried to replicate the error but I got a different error this time. nWhat I do is save the file when the simulation finishes (for backup), and then save the file again somewhere else to continue the simulation. So for the last time ( when I asked the question) and this time (today) I used the same backup file (save it somewhere new so nothing happens to the backup file) and did the same procedure but this time I got this new error. nThis is what I did. I ran this simulation for 2 [s] with a time step of 0.01 [s] a week ago. It worked fine. then I wanted to continue the simulation, so today I changed the End time in system coupling to 2.1 [s]. and I get this errornSo, I tried to run restart it from 1.92 [s], so I first went to the setup part in the transient module and change the restarting time-step to 1.92 [s] (following image)nthen closed the Ansys mechanical and updated the setup, For the next step I open the solution part of the Fluent module and change the solution file to 1.9[s], and read it.nthen closed the fluent and opened the coupling module. Changed the coupling initialization to 1.9 [s]. nand then update the coupling and get this error (couldn't find R file).n