Water Jet Breakup Using VOF-to-DPM Transition

Description

Water Jet Breakup Using VOF-to-DPM Transition in ANSYS Fluent

Introduction

This report presents a Computational Fluid Dynamics (CFD) analysis of water jet breakup using the Volume of Fluid (VOF) to Discrete Phase Model (DPM) transition method in ANSYS Fluent. The study investigates the complex multiphase flow behavior and particle tracking in jet breakup processes.

The geometry was designed using ANSYS Design Modeler, consisting of a rectangular enclosure with water injection on the left side and air flow on the right side. The meshing process, carried out using ANSYS Meshing, resulted in a high-quality structured mesh comprising 3,157,674 elements. Adaptive mesh refinement was employed to ensure high resolution in critical areas, particularly at the water-air interface.

Methodology

Pressure-based, transient solver with a time step of 4e-6 seconds for 10,000 steps

VOF model with Implicit Body Force for multiphase modeling

SST K-Omega turbulence model with SBES Hybrid Model and WALE Subgrid-Scale Model

DPM with two-way coupling and unsteady particle tracking

VOF-to-DPM refinement method and PISO scheme for pressure-velocity coupling

Results

The simulation provided insights into the water jet breakup process:

Particle track visualization shows residence times ranging from 0 to 1.37e-02 seconds, indicating droplet dispersion and lifetime.

The geometry visualization illustrates the interaction between the water jet and airflow.

Adaptive mesh refinement ensures high resolution at the water-air interface.

Volume fraction contours reveal the water distribution within the domain.

Key observations include the successful capture of the transition from continuous water jet to discrete droplets, the effectiveness of adaptive mesh refinement, and the complex dynamics of droplet dispersion and lifetime within the domain.