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Flow regime transitions in flow blurring injection through a CFD parametric study.
S Amirreza S Madani1, Erfan Vaezi2, Mohammad Reza Morad2
1Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands.
Scientific Reports
|August 2, 2025
Summary
Flow-blurring atomization uses internal turbulent mixing to create fine sprays. This study found liquid mass flow rate and viscosity significantly impact spray penetration length, offering insights for injector optimization.
Area of Science:
- Fluid Dynamics
- Multiphase Flow
- Spray Atomization
Background:
- Flow-blurring (FB) is an advanced twin-fluid atomization method.
- It relies on internal turbulent mixing to produce fine sprays.
- Understanding FB injector dynamics is crucial for optimizing spray characteristics.
Purpose of the Study:
- To conduct a parametric computational investigation of a flow-blurring injector.
- To analyze flow dynamics under various air-to-liquid mass flow rate ratios (ALRs).
- To identify key parameters influencing spray penetration length and flow regimes.
Main Methods:
- Utilized a validated unsteady two-phase solver based on the Volume of Fluid (VOF) method.
- Modeled an FB injector operating with air and various liquids at ambient pressure.
- Performed a screening analysis of 32 cases with varying ALRs and fluid properties.
Main Results:
- Identified three distinct flow regimes: air-dominant, liquid-dominant, and bubbly flow.
- Determined that liquid mass flow rate and dynamic viscosity are the primary drivers of penetration length.
- Observed spray penetration lengths ranging from 2 mm to 8.5 mm.
- Found significant two-way interactions between parameters, such as the combined effect of liquid and air mass flow rates.
Conclusions:
- Liquid mass flow rate and dynamic viscosity are critical for controlling spray penetration in FB injectors.
- The study provides a foundational understanding of FB injector flow dynamics.
- These findings pave the way for optimizing FB injector performance in diverse applications.
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