FRICTION FRACTOR AND HOLDUP STUDIES FOR LUBRICATED PIPELINING .2. LAMINAR AND K-EPSILON MODELS OF ECCENTRIC CORE FLOW

A model of core-annular flow in which the oil core is a perfect cylind er with generators parallel to the pipe wall, but off-center, is studi ed in laminar and turbulent flow to assess the effects of eccentricity and the volume flow rate ratio on the friction factor and holdup rati o. The study is tilted toward water lubrication of heavy crude viscous oil. For the turbulence analysis, the water is assumed to be turbulen t and the core laminar. A standard k-epsilon model with a low Reynolds number capability is adopted for the turbulence case. The agreement b etween model predictions, which have no adjustable parameters, and exp erimental and field data from all sources, is satisfactory.