Experimental research and model development on interfacial drag in rectangle channel bubbly and slug flow

Abstract As one of the most important constitutive models, interfacial drag determines the phase distribution directly and impose significant influences on pressure drop and heat transfer. Due to the limited study on interfacial drag for rectangle channel, experimental research and model development were performed in this paper. The air-water flow experiments in rectangular channels were carried out to obtain local parameters such as void fraction, interfacial area concentration and bubble chord length. These parameters were all characterized with core peak distribution except for the situations of void fraction at lower gas velocity and interfacial area concentration at higher gas velocity. The development of interfacial drag model in bubbly and slug flow was proposed based on the experimental data. The drag coefficient and interfacial area concentration in bubbly and slug flow were modified for distorted bubble, Taylor bubble and liquid slug respectively. Further validation was performed with system analysis codes. Better prediction of interfacial area concentration and void fraction, as well as numerical stability were obtained, proving the validity of interfacial drag model developed for rectangle channel bubbly and slug flow.