Abstract
Thermal fatigue crack may initiate at mixing tee where high and low temperature fluids flow in and mix. This paper shows some results of numerical simulations that were conducted to evaluate temperature fluctuation in mixing tee using some turbulence models. Accuracy of these simulations was examined for a velocity condition of WATLON experiments performed at Japan Atomic Energy Agency: wall jet condition that the jet from the branch pipe flowed along the main pipe wall. Time-averaged temperature distribution with LES and DES agreed well with the experimental results, but the intensity of temperature fluctuation in the wake ofjet had some differences. RANS model, such as SST model, can't simulate the fluctuation around the jet although the same mesh, boundary conditions and time step were used in the calculation.
