| Title |
A Study on the Helical Flow of Newtonian and non-Newtonian fluid |
| Keywords |
Transitional flow ; 천이유동 ; Concentric annulus ; 동심환형관 ; Skin friction coefficient ; 표면마찰계수 ; Rotating flow ; 회전유동 ; Critical Reynolds number ; 임계레이놀즈수 |
| Abstract |
This study concerns the characteristics of helical flow in a concentric and eccentric annulus with a diameter ratio of 0.52 and 0.9, whose outer cylinders are stationary and inner ones are rotating. Pressure losses and skin friction coefficients have been measured for fully developed flows of water and 0.2% aqueous of sodium carboxymethyl cellulose(CMC), respectively, when the inner cylinder rotates at the speed of 0～500 rpm. The effect of rotation on the skin friction coefficient is significantly dependent on the flow regime. In all flow regimes, the skin friction coefficient is increased by the inner cylinder rotation. This study shows the change of skin friction coefficient and wall shear stress corresponding to the variation of rotating speed of the inner cylinder, radius ratio, eccentricity, and working fluids. |