[emmkell]

I have a time dependent model, with a UDF to apply a temperature gradient to one of the walls up to a certain time.

After 60 seconds, another UDF then tells the velocity inlet there is flow for 2 seconds, so a sort of on/off message for the velocity inlet.

Is there a way of telling the velocity inlet to act as a wall until such time as the flow occurs? The temperature of the inlet is not changing when the temperature gradient is applied to the heated wall. I assume this is because in the thermal heading of the velocity inlet boundary condition, the temperature must be set. I want it to change with the rest of the material until such time as flow occurs.

Is there a way of doing this? Something to do with Execute on demand? I've attached a picture which might explain it better.

Any help would be really appreciated!