180° Bend에서 층류 정상유동의 유동특성에 관한 연구

A Study on Flow Characteristics of Laminar Steady Flow in 180° Bend

In this study, The flow characteristics of developing laminar steady flow in a 180° bend of square cross-section curved duct are experimentally investigated using laser-doppler velocimetry. The critical Dean number in a curved duct for laminar steady flows is larger rather than in a straight duct. The friction factor in a straight duct in correlated as ist=57/Rest in laminar flow region of the fully developed steady flow, and friction factors for the square duct are smaller than those for the circylar duct at the same Reynolds number. And the entrance length is well agreed with the equation, ∅=49Re1/3Rc-1/2 suggested by Austin, L. R. and Seader, J. D. in the present experimental conditions.