Large eddy simulation of thermal mixing under boiling water reactor conditions

Published: 26 July 2019| Version 2 | DOI: 10.17632/pdmymp8sxj.2
Mattia Bergagio


Q_and_Uz/Uz_AVG__view_k__0.6,0.73__Q_0.5.png: time-averaged Q-criterion isocontours colored by time-averaged axial velocity. k = view number. k = 1: at θ = 90°. k = 2: at θ = 180°. k = 3: at θ = 270°. k = 4: at θ = 360°. Q = 0.5 s^-2. Start time t_0 = 19.2 s. 17.5e-3 m ≤ (x^2 + y^2)^0.5 ≤ 22.5e-3 m. 0.60 m ≤ z ≤ 0.73 m. These figures help to interpret Fig. 9 in the related paper. U_and_T/i__time_j__z_0.67.png: field i at time j, in s, at z = 0.67 m. i = T (i.e., temperature) or U (i.e., velocity magnitude). LES results. Water domain. These figures are part of Figs. 7 and 8 in the related paper. The in-plane velocity vectors can be clearly seen here. HMS1.pdf: Hilbert-Huang marginal spectra of inner-surface temperatures at (90°, 0.67 m), (270°, 0.67 m), (360°, 0.67 m). Experimental data. mean(dimensionless T)_exp.pdf: time-averaged dimensionless inner-surface temperatures in the mixing region. Experimental values. mean(dimensionless T)_LES.pdf: time-averaged dimensionless inner-surface temperatures in the mixing region. LES values. mean(dimensionless T)_exp.pdf and mean(dimensionless T)_LES.pdf prove that it is challenging to compare LES and experimental temperatures in terms of local means. strr_range.pdf: radial stress range. sttt_range.pdf: hoop stress range. stzz_range.pdf: axial stress range. Same as Fig. 14d. Stresses in the vicinity of the inner surface, at 0.993 R_io. Values in Pa. Start time t_0 = 19.2 s. Axial and hoop stresses show similar ranges.



Kungliga Tekniska Hogskolan


Nuclear Engineering, Finite Element Methods, Finite Volume Methods, Computational Fluid Dynamics