Flow patterns of vertical and horizontal adiabatic two-phase flow in a plate heat exchanger single channel with uniform gas-liquid distribution

摘要

Flow patterns of air-water two-phase flow are investigated for various flow directions in atransparent cross-corrugated channel with almost ideal, i. e. uniform, gas-liquid injection. A flowpattern map is derived from visual classification of photographs. Flow directions have little effect onflow patterns. This is attributed to the centrifugal force often dominating over buoyancy in thehelical flow path. The ratio of centrifugal to buoyancy force is quantified by the centrifugal Froudenumber. Bubbly flow patterns are pre-determined by the homogeneous void fraction in the sameway as in tubes. However, so-called slug flow is not observed, although being reported for crosscorrugatedchannels by other authors. Slugging is caused by non-uniform inlet conditions andother oscillating two-phase phenomena in the experimental periphery of the cross-corrugatedchannel.