When two fluids at different temperature are mixed, a spatial and time temperature fluctuation occurs. If this fluctuation is high, it may causes damages to the structure due to high cycle thermal fatigue and this is called as thermal stripping phenomena. This phenomenon is important for safety of reactors, which uses liquid metal as the coolant. Mixing areas of low and high temperature fluids exist in atomic as well as in general plant. Several experiments are done to evaluate thermal stripping phenomena. Temperature distribution and velocity field in the mixing tee can be studied by experiments, by carrying out plant trails or water modeling but are costly and time consuming. Now Computational Fluid Dynamics [CFD] is an alternative to reduce the number of experiments required. And CFD reduces cost and time required for the designing process. Further it provides more insight into the flow process.