An LES study and ... in-line tube-banks 33 x y 4.4 4.6 4.8 5 5.2 5.4 5.6 5.8 6 7.5 8 8.5 (a) C1 x y 7 7.5 8 7.2 7.4 7.6 7.8 8 8.2 8.4 8.6 8.8 (b) C2 x y 9 9.5 10 10.5 7.5 8 8.5 (c) C3 x y 11.5 12 12.5 13 7.5 8 8.5 (d) C4 Fig. 10: Instantaneous velocity vector map in the middle plane of flow domain (a) C1 (b) C2 , (c) C3 (d) C4