Flow pattern and pressure drop analysis of two-phase segmented flow driven by a thermomagnetic pump

Abstract

The two-phase segmented flow is a flow pattern in which two immiscible fluids alternate in a flow channel with distinct segments. In this study, a thermomagnetic pump operated by heat and an external magnetic field was used to drive the flow and the temperature-sensitive magnetic fluid (TSMF) was chosen as the continuous-phase fluid to generate a two-phase segmented flow. The dispersed-phase fluid was selected as air or deionized water driven by a syringe pump. The two-phase segmented flow experiments were conducted to investigate the relation between segment length and the dispersed-continuous phase flow rate ratio at the air flow rate from 0.90 ml/h to 4.49 ml/h for air-TSMF experiment and water flow rate from 0.36 ml/h to 0.72 ml/h for water-TSMF experiment. The ratio was proportional to the bubble/droplet length and inversely proportional to the slug length. The air/water length per channel width can be up to 3.28 and 1.79, respectively, at the highest air/water flow rate in the current experiment. Moreover, the pressure drop was measured to increase with the dispersed-continuous phase flow rate ratio. The maximum pressure drop was observed as 428.2 Pa in the water-TSMF experiment with the highest water flow rate and the maximum pressure drop was 314.7 Pa for the air-TSMF experiment. These findings provide valuable insights for controlling the segment length in the two-phase segmented flow driven by a thermomagnetic pump and it could be used as precise control of liquid/gas fuel delivery in a micro-propulsion system in small satellites.