Eulerian: Pipe Flow with Multi-Speed AMUSIG
The Adaptive Multiple Size-Group (AMUSIG) model predicts the size distribution of particles (droplets or bubbles) in a dispersed multiphase flow regime. This tutorial demonstrates how to use the AMUSIG model for predicting the size distribution of hexane droplets in water. The water is flowing up a vertical pipe in which a concentric orifice increases turbulence and so accelerates droplet breakup.
The collection of droplets is modeled using five groups of representative computational particles. Each group consists of identical particles, and has its own size and its own velocity. A population balance is solved for each size-group in each cell.
The AMUSIG model is locally adaptive so that each size-group carries approximately the same share of the hexane phase. This method is efficient and benefits fully from the computational expense of multi-speed modeling. Multi-speed modeling is necessary when analyzing strong interactions between the size distribution and the flow.
The geometry of the pipe is shown below (not to scale). The flow enters the pipe at a velocity of 0.5 m/s and is composed of 99% water (by volume fraction) and 1% hexane.
