A Warning message in AFT xStream

Full Message text is:

Transient temperature was below fluid minimum temperature at X seconds. Results after this time may not be valid.

 

This warning informs the user that the temperature went below the minimum temperature in the fluid database during the transient simulation. xStream will extrapolate below the minimum temperature and assume the fluid remains in the gas phase. In some cases the minimum temperature for the fluid database represents saturation conditions, in which case xStream will be extrapolating below the saturation line.

Results from the MOC Transient after the transient temperature reaches the minimum temperature should be treated with caution.