Some problems with simulation in a Forced Convection problem
 

Hello!

Im a beginner in the CFD world and I would be thankful to anyone who can helps me.
I'm trying to model a cooling curve. The flow is passing perpendiculary to a group of copper cilinders. I have meshed one of them because in reality it is a thermal sensor. I have some experimental data and its plot of (T-Tenvironmental) vs time of this sensor.
In fluent I'm using the k-e RNG model because there are not big pressure gradients in the model (inlet and outlet are at atmospheric pressure). I'm also using an Enhanced Wall Treatment and I have already a y+ less than 1 around my sensor.

The problem is that I get a wrong cooling curve in CFD, the slope of this curve is higger than the slope of experimental data, this one decreases smoother. I don't know what could be happening... if are needed more details please ask to me. Thanks for advance! :)