Fig. 1. Diagram of physical model of air supply pipe

Fig. 2. Model of static muddy device (a) Structure 1, (b) Structure 2, (c) Structure 3

Fig. 3. Mesh (a) Pipe, (b) Mixing device

Fig. 4. Flow diagram of air supply pipe

Fig. 5. Tangential velocity distribution vector diagram of circular tube section with vertical distance (from the cross-section of the pipeline to the outlet of stirring device) of (a) 0.2 m, (b) 1.4 m, (c) 3.0 m

Fig. 6. Aerosol concentration distribution with vertical distance (from the cross-section of the pipeline to the outlet of stirring device) of (a) 0.2 m, (b) 1.4 m, (c) 2.6 m

Fig. 7. COV of concentration vs. distance

Fig. 8. Velocity distribution of cross-section at different distances after mixing in structure 1 (a) 0.2 m, (b) 1.4 m, (c) 2.6 m

Fig. 9. Aerosol distribution of cross-section at different distances after mixing in structure 1 (a) 0.2 m, (b) 1.4 m, (c) 2.6 m

Fig. 10. Velocity distributions of structure 2 (a,b,c) and structure 3 (d,e,f) at cross sections with different distance of (a, d) 0.2 m, (b, e) 1.4 m, (c, f) 2.6 m

Fig. 11. Swirling strength generated by different structures in section at distance of 0.2 m (a) No.1, (b) No.2, (c) No.3

Fig. 12. Variation of COV of aerosol concentration with distance

Fig. 13. Change in COV of velocity with distance

Fig. 14. Variation of mean cyclone angle with distance