<p>Pressure-swirl atomizers (PSAs) are widely used in industry due to their advantages, necessitating a comprehensive analysis of internal and external flow dynamics. This study employs the interIsoFoam solver in OpenFOAM with the k-Eqn LES model to investigate transient three-dimensional flow in a PSA and the primary atomization of the exiting conical liquid sheet. Validation against experimental data demonstrates good agreement, with average errors of 0.05% (spray cone angle), 3.4% (discharge coefficient), and 0.07% (air core diameter). The simulation explores the complex internal flow phenomena of the atomizer and the outlet liquid sheet, including the air core structure and mechanisms of liquid sheet breakup. FFT spectral analysis identifies the dominant high-energy frequencies and reveals similarities between the frequencies of the internal flow within the atomizer and those of the exiting liquid sheet. The Proper Orthogonal Decomposition (POD) technique captures the energetic structures of the atomizer’s internal and external flows, indicating that, similar to the temporal domain, the energetic phenomena of internal flow impact atomization in the frequency domain. The POD analysis underscores the significance of energetic internal flow features, such as helical air PVC, strong shear layers, and liquid vortices, in shaping external flow structures like strong shear layers, surface waves, inner recirculation zones, and air vortices. This culminates in the formation of a stagnation point and the liquid sheet breakup at a height of <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="40997_2025_861_Article_IEq1.gif" Format="GIF" Height="19" Rendition="HTML" Resolution="72" Type="Linedraw" Width="97" /> </InlineMediaObject> <EquationSource Format="TEX">$z/{D}_{o}=10.83$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>z</mi> <mo stretchy="false">/</mo> <msub> <mi>D</mi> <mi>o</mi> </msub> <mo>=</mo> <mn>10.83</mn> </mrow> </math></EquationSource> </InlineEquation>. The study emphasizes the influence of internal flow structures on atomization mechanisms and liquid sheet breakup, underscoring the pivotal role of internal energetic flow features in the process.</p>

Exploring Dynamics of Transient Flow Through a Pressure Swirl Atomizer: A Numerical Study Employing POD Method and Spectral Analysis

期刊论文
发表日期：

2025年4月11日

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Atiyeh Sarabadani,
Reza Ebrahimi

摘要

Pressure-swirl atomizers (PSAs) are widely used in industry due to their advantages, necessitating a comprehensive analysis of internal and external flow dynamics. This study employs the interIsoFoam solver in OpenFOAM with the k-Eqn LES model to investigate transient three-dimensional flow in a PSA and the primary atomization of the exiting conical liquid sheet. Validation against experimental data demonstrates good agreement, with average errors of 0.05% (spray cone angle), 3.4% (discharge coefficient), and 0.07% (air core diameter). The simulation explores the complex internal flow phenomena of the atomizer and the outlet liquid sheet, including the air core structure and mechanisms of liquid sheet breakup. FFT spectral analysis identifies the dominant high-energy frequencies and reveals similarities between the frequencies of the internal flow within the atomizer and those of the exiting liquid sheet. The Proper Orthogonal Decomposition (POD) technique captures the energetic structures of the atomizer’s internal and external flows, indicating that, similar to the temporal domain, the energetic phenomena of internal flow impact atomization in the frequency domain. The POD analysis underscores the significance of energetic internal flow features, such as helical air PVC, strong shear layers, and liquid vortices, in shaping external flow structures like strong shear layers, surface waves, inner recirculation zones, and air vortices. This culminates in the formation of a stagnation point and the liquid sheet breakup at a height of $z/{D}_{o}=10.83$ $z / D_{o} = 10.83$ . The study emphasizes the influence of internal flow structures on atomization mechanisms and liquid sheet breakup, underscoring the pivotal role of internal energetic flow features in the process.