[Sai Krishna]

i want to simulate an experiment in fluent in which hot air flows through nozzle and outer wall temperature is measured. nozzle is made up of steel. i made nozzle geometry(axi symmetric) in icem cfd providing thickness for the walls. the problem is when i did simulation in fluent, i am not able to get the temperature gradient in the solid walls and whole body its showing at the same temperature of the gas (which i gave as input.)
my doubts are:
1.i should get a boundary layer on inner side of the walls, which i am not
getting.
2.temperature gradient in steel is not occurring.(steel thickness is 5 mm)
3.as the experiment is conducted not in controlled environment, i provided a
domain with pressure far field condition with pressure as 1 bar and mach
number as 0.001(since i assumed the air is in almost stand still condition).
but this provided very vague results in which the body temperature is
raising more than the entry fluid temperature.

my boundary conditions are
4 bar pressure, 4 kg/sec mass flow rate, 1650K temperature - inlet
gases are exit to atmosphere

models - k-epsilon, realizable, enhanced wall treatment , thermal effects.

i did 4 revisions for this, none of them gave the satisfied results.

help in this will be greatly appreciated

thank you.