[ZYJ0999]

I have encountered an unsolvable problem when using Fluent: during simulation, I fail to change the type of boundary condition on certain side by comparing the pressure within the fluid domain with a determined value.

None of the following methods I've tried worked:

1. Fluent's built-in Dynamic-Events can only change the boundary condition type by setting the number of crank rotation angles or flow time, in which the valve opening and closing time is very complex to calculate;

2. The Expression that come with Fluent as well as UDF files disenable us to write valid command statements. There is no function in the library to convert the boundary conditions, so the UDF file written will not recognize compilation. Even if we could write the corresponding code, we could not find a link between it and the Boundary Condition Type Settings.

I think there must be a way to realize my idea, because Dynamic-Events can determine whether the boundary condition is changed by comparing a certain value (Angle or time), and pressure is also a computable parameter, why can't the two be combined together through code?

I have also consulted some netizens, but all the replies are negative. So I come here for help. I hope the simulation masters in CFD-online can answer my doubts, I will be very grateful.