Effect of attack and cone angels on air flow characteristics for staggered wing shaped tubes bundle

• Published in: Heat and mass transfer Vol. 51; no. 7; pp. 1001 - 1016
• Main Authors: Sayed Ahmed, Sayed E., Ibrahiem, Emad Z., Mesalhy, Osama M., Abdelatief, Mohamed A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-07-2015
• Subjects: Engineering; Engineering Thermodynamics; Heat and Mass Transfer; Industrial Chemistry/Chemical Engineering; Original; Thermodynamics; Pressure Drop; Heat Exchanger; Turbulent Kinetic Energy; Tube Bundle; Nusselt Number
• ISSN: 0947-7411; 1432-1181
• DOI: 10.1007/s00231-014-1473-3

An experimental and numerical study has been conducted to clarify fluid flow characteristics and pressure drop distributions of a cross-flow heat exchanger employing staggered wing-shaped tubes at different angels of attack. The water-side Re
w
and the air-side Re
a
were at 5 × 10
2
and at from 1.8 × 10
3
to 9.7 × 10
3
, respectively. Three cases of the tubes arrangements with various angles of attack, row angles of attack and 90° cone angles were employed at the considered Re
a
range. Correlation of pressure drop coefficient P
dc
in terms of Re
a
, design parameters for the studied cases were presented. The flow pattern around the staggered wing-shaped tubes bundle were predicted using the commercial CFD FLUENT 6.3.26 software package. Results indicated that the values of P
dc
increased with the angle of attack from 0° to 45°, while the opposite was true for angles of attack from 135° to 180°. The values of P
dc
for the arrangements of (θ
1,2,3
 = 45°), (θ
1
 = 45°, θ
2
 = 0°, θ
3
 = 45°), and (θ
1,2,3
 = 0°) were lower than those for the arrangement of (ϕ
1
 = ϕ
2
 = ϕ
3
 = 90°) by about 33, 53, and 91 %, respectively. Comparisons between the experimental and numerical results of the present study and those obtained by similar previous studies showed good agreements.