I am trying to couple fluent and transient structural to study the displacement of a flexible gate when a water column collapses, the problem is a multi phase problem with water and air as the two phases, I have 2 questions

Question 1. I did the simulation without coupling and it works fine but when I couple I get these two errors 

"Update failed for the Solution component in System Coupling.  The coupled update for system Fluid Flow (Fluent) threw an exception. An error occurred in FLUENT when initializng the flow

An error occurred in FLUENT when initializng the flow"




"(DP 0) System coupling run completed with errors.  Fluid Flow (Fluent) (Solution 1) reported: Exception encountered when the coupling service requested ChartableData->GetRootLevelName: Communication socket unexpectedly disconnected. Please do not save the project if you would like to recover to the last saved state."


I tried initializing using the hybrid and standard method also tried changing the mesh, reducing the time step nothing works

Question 2. If I decide to do a one way analysis instead to get the deformations of the gate by transferring the pressure which is better, using static structural or transient structural to get the deformation values at a specific time.