[Not Lah Enough]

Hi all,

I am running into a very weird problem when simulating a three-phase VOF case, consisting of water, liquid ammonia, and vapor ammonia. I already looked up other queries in this forum to see whether someone had encountered similar problem, to no avail.

The problem statement is shown in the illustration below. Liquid refrigerated ammonia (initial temperature at inlet below boiling point of -33.4 C) enters the water column from below. The water temperature is set at 30 C, so it's well above the boiling point of ammonia that heat transfer into the ammonia phase would ensure the liquid ammonia is vaporized rather immediately, before subsequently dissolved into the surrounding water.



Instead, despite the relatively rapid temperature increase above the boiling point throughout the ammonia phase, almost no liquid ammonia turned into vapor (taken at t = 1.5s, snapshots from top to bottom: temperature, ammonia vapor, water fractions).







Could someone let me know what's missing here? The case file is given in the GD link below for your perusal. Thanks in advance.

https://drive.google.com/drive/folde...Tk?usp=sharing