Effect of Injector Geometry in Breakup of Liquid Jet in Crossflow Insights from POD

TL;DR

This study investigates how injector tube length-to-diameter ratio affects liquid jet stability and breakup in crossflow, using POD analysis to understand the underlying flow dynamics and effects of injector geometry.

Contribution

It introduces a systematic analysis of injector geometry effects on jet breakup modes using POD, providing new insights into turbulence and instability mechanisms.

Findings

Increased L/D leads to more turbulent and unstable jet surfaces.

Higher L/D causes earlier breakup and reduced jet penetration.

POD analysis reveals specific mode shapes associated with breakup processes.

Abstract

The present study aims to investigate the role of injector geometry, particularly injector tube length to diameter ratio (L/D) in liquid jet stability and breakup in presence of crossflow. Water is injected into a crossflow of air. Aerodynamic Weber number (We) and liquid Reynolds number (Rel) are systematically varied to observe various breakup modes. Bag breakup and surface stripping is observed for different operating conditions. Time-resolved jet trajectory images are processed using Proper Orthogonal Decomposition (POD) algorithm. POD mode shapes and corresponding Power Spectral Density (PSD) plots are analyzed to study breakup process and probe role of injector geometry effects. Further, high-resolution images are captured for the near-nozzle region. Detailed comparison is made for various cases. It is observed that with increase in (L/D), the jet surface becomes more turbulent and unstable. This results in early breakup and lower jet penetration