Application of LES in Simulation of Fluid Buffet on Core Barrel Excited by FIV

The fluid field in down comer between reactor vessel and core barrel of Qingshan II phase 1:5 model test is simulated with LES,and the pulse pressure distribution on the surface of the core barrel is obtained.The effect of Smagorinsky coefficient in Smagorinsky sub-grid model is studied and the result shows that the pressure RMS decreases with the increase of the Smagorinsky coefficient.The comparison with the experiment shows that when the Smagorinsky coefficient equals 0.18,it is suitable for the model test.The pulse pressure RMS of LES agrees with the experiment,and the difference of the pulse pressure PSD between LES and the experiment is discussed.The effect on the pressure by fluid velocity is studied and the distribution of pressure in space is obtained.