[chachin]

I am trying to create subcooled flow boiling through a duct under the influence of gravity in transient condition , so as to determine the impact of temperature gradient on the walls. the problem is that i couldn't get a proper temperature rise in fluid. fluid flows at a constant temperature till close to the outlet and then there is a sudden change in temperature ( ie the phase change the is supposed to occur gradually is taking place suddenly at the exit) can anyone help me ??

Am using Eulerian model, RPI boiling

also plz tell me is it possible to model boiling without using a udf ?