Drag Coefficient and Stanton Number Behavior in Fluid Flow Across a Bundle of Wing-Shaped Tubes

摘要

Transient numerical simulations of fluid and heat flow were performed for eight heat exchanger segments with cylindrical and wing-shaped tubes in staggered arrangement. Their hydraulic diameters d{sub}h were from 0.5824 to 3.899 cm for the cylindrical tubes, and from 0.5413 to 3.594 cm for the wing-shaped tubes. Based on the recorded time distributions of velocity u{sub}f(t) and temperature T{sub}f(t), time average Reynolds number Rc{top}-, drag coefficient (C{top}-){sub}d, and Stanton number St{top}-were calculated. In general, the drag coefficient and the Stanton number are smaller for the wing-shaped tubes than for the cylindrical tubes. However, with an increasing hydraulic diameter, these differences between both forms of tubes diminish. The time average values were further used to construct the drag coefficient and the Stanton number as polynomial functions (C{top}-){sub}d(d{sub}h,Rc{top}-) and St{top}-(d{sub}h,Rc{top}-).