PSI - Issue 73

Juraj Králik et al. / Procedia Structural Integrity 73 (2025) 73–80 Juraj Králik/ Structural Integrity Procedia 00 (2025) 000–000

75 3

Fig. 2. Configuration of NPP buildings with the reactor VVER 440/213 - EBO V2.

The NPP objects were assembled on a 3D printer in a scale of 1: 300. The directions of the tunnel table were modified by wind directions 14, 104, 194 and 284 (Fig.1) to consider the perpendicular wind directions to the NPP The NPP buildings with the reactor VVER 440/213 consist the turbine hall (SO 490), lengthwise side buildings (SO 805), cross side buildings (SO 806, 807), reactor building and bubble condenser (SO 800) (see Fig. 2). The levels of NPP building roofs are different – as follows: SO490 at level 30.85 to 31.90m, SO 800 at level 48.81 to 49.84 m, SO 805 at level 38.20 to 39.18 m, SO 806 and 807 at level 38.20 to 39.18 m The ventilation chimney (SO 460) was one object near the NPP buildings with the reactor VVER 440 (Fig.2). This structure is made of reinforced concrete with the following parameters: the high 125m, the lower outer diameter ø 10.95m to a height + 30m, from level + 30m conically decreasing to the top outer diameter ø 5.8 m, the thickness of the wall at the base is 0.525m, at the top 0.2m. The external wind parameters c pe was defined as follows

p

,

(1)

c

=

pe

2

1/ 2

v ρ

⋅ ⋅

where p is the differential pressure on the external surface of the model to the static pressure and in the denominator is the wind pressure corresponding to the reference wind speed at the upper level of the roof. The results from the experimental analysis were used for the evaluate of the numerical model of the NPP structures

and the numerical methods in software ANSYS-FLUENT. 3. Numerical analysis of extreme wind in ANSYS-FLUENT

The numerical analysis of the wind impact to the ventilation chimney were considered using software ANSYS FLUENT. The k- ω model was used for the analysis of the wind impact to the chimney structure considering the effects of the interaction with the other NPP structures in space. In the case of a 3D model, the following fluid space is recommended - in front of the 5H model, behind the 10H model, above the 4H model and on the 5H (H – is the characteristic model dimension). The overall dimensions of the computational domain are 1172 × 2154 × 750 m. A total of 14 characteristic computational models in 3D space were created. The FE model was created with 1.122.685 nodes and 6.340.840 tetrahedron elements type (Fig. 3). Subsequently, the entire domain within the