[ameya1711]

I am trying to model natural convection in a sensor. The sensor will be mounted on pipe maintained at 250 deg C. We have connected sensors via strap on this assembly. Thus the contact between the pipe and strap contains air gap with max gap of 0.5mm approx. Above this strap we have SS rod which leads to the sensor housing.
The problem when we performed the experiment and a CFD simulation, the difference in temperature reported in CFD is 30 deg C more than experimental value at the same locations!!!!.( This 30 deg C difference is contact across the length by coincident or something else). Although I am able to capture physics right.

Below are the details of Simulations
Solver:- Fluent 16.1
Laminar flow
Air as ideal gas
Pressure scheme:- Presto