Page 216 - Introduction to Computational Fluid Dynamics

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6.4 APPLICATIONS
S L S L May 25, 2005 11:10 195

S T
S T

D

D

INLINE ARRAY STAGGERED ARRAY
Figure 6.14. Flow across banks of tubes.

of aligned and staggered arrangement of tubes. The important geometric param-
eters are (see Figure 6.14) longitudinal pitch S L , transverse pitch S T , and tube
diameter D. Here, we consider cases of S L /D = S T /D = 2 for the inline array and
S L /D = S T /D = 1.5 for the staggered array.
For the purposes of computations, however, the smallest symmetric domain
must be considered. Such domains are mapped by curvilinear grids as shown in
Figure 6.15. In these domains, the north and south boundaries are partly symmetric
and partly occupied by tube wall but the west and east boundaries are periodic. Note,
however, that in the inline array, the periodicity is even whereas a cross-periodicity
occurs in the staggered array with respect to the u 2 velocity. Computations have
been performed using 45 × 15 grids for the inline array and 41 × 15 grids for the
staggered array. For turbulent flow, the standard HRE model with two-layer wall

INLINE ARRAY STAGGERED ARRAY
symmetry symmetry
S L S L
periodic periodic wall periodic

S T /2 S T /2

wall wall periodic wall

symmetry symmetry
Figure 6.15. Computational domains for inline and staggered arrays.