PSI - Issue 63

Ivan Kolos et al. / Procedia Structural Integrity 63 (2024) 13–20

16

3.2. Boundary conditions Bottom faces of the domain and walls of the truck have wall boundary condition. Top face of domain is zero shear wall. Front, back, left and right sides of domain are velocity inlets or pressure outlets depending on direction of the wind flow according Fig. 3. There are also interfaces between moving subdomain and surrounding domain allowing smooth fluid and particles transport. Inlet wind velocity magnitude is 20 m/s. The vehicle moves with constant speed 25 m/s.

Fig. 3. Variants of wind flow.

3.3. Solutions and results The aim of the analysis is to evaluate the amount of droplets falling from a passing truck on the created sampling zones in the analytic zone of the domain. Standard k- ε turbulent model including wall functions was used to model wind flow. Discrete phase is modeled by Euler-Lagrange approach. Three sampling zones are defined in the analytic part of domain at distances of 5, 9 and 13 m, they are 1.5 m high (sampling zone 5, sampling zone 9 and sampling zone 13). During the vehicle's travel, the sampling zones are used to monitor the particles that fly through them. As already mentioned above, four variants of the wind flow are solved in the simulations. A detailed description of these variants and how they differ can be seen from Table 1.

Table 1. Variants of the wind flow in the simulations.

Variants of the wind flow

Wind flow side

Orientation of the flow relative to the position and movement of the vehicle

Variant 1 Variant 2 Variant 3 Variant 4

the right side the right side the left side the left side

In the front against the vehicle

In the back in the direction of the vehicle

In the front against the vehicle

In the back in the direction of the vehicle

The results of the performed simulations are shown in the following Fig. 4 to Fig. 8. Aerosol wake behind and passing truck for all wind direction are shown in Fig. 4. The figures clearly show how the different wind direction affects the resulting particle trajectory in the wake behind the vehicle.