Flow characterisation of monopropylene glycol ice slurry through a horizontal U-bend: A numerical approach

Abstract

Ice slurries are used as secondary refrigerants in cooling applications. To determine optimal operating conditions, it is most important to understand then identify the conditions offering the best compromise between high heat transfer and low pressure drop. This study aims to numerically examine the flow characteristics of an ice slurry through a horizontal U-bend. An Eulerian two-phase model was used to investigate the effect of inlet flow velocity, particle diameter and ice volume fraction on the particle distribution and pressure drop throughout the U-bend. Particle diameter and ice volume fraction showed opposing influence on particle distribution. It was also found that the wall shear stress distribution in a bend differs from that of a straight pipe, as the distribution of shear stress is more significant on the right hand side of the wall. Results also showed that the pressure drop generally increases with increasing flow velocity and ice volume fraction. However, the influence of increasing particle diameter was found to depend on the flow velocity. The increase of particle diameter led to the increase of pressure drop at low velocity, however caused decrease of pressure drop at higher velocity.