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Updated: Jul 5, 2026
13:02
Three-dimensional Particle Tracking Velocimetry for Turbulence Applications: Case of a Jet Flow
Published on: February 27, 2016
A uniformly valid asymptotic solution for a transverse jet and its linear stability analysis
Robert E Kelly1, Leonardo S de B Alves
1Department of Mechanical and Aerospace Engineering, University of California at Los Angeles, Los Angeles, CA 90095-1597, USA.
Summary
This study analyzes the flow near a transverse jet, finding that increased crossflow enhances the jet's instability. These findings align with experimental data on jet behavior.
Area of Science:
- Fluid dynamics
- Aerodynamics
- Turbulence research
Background:
- Understanding the nearfield flow of transverse jets is crucial for applications like combustion and pollutant dispersion.
- Previous models often simplified the complex interactions between the jet and crossflow, particularly at high Reynolds numbers.
Purpose of the Study:
- To develop a theoretical model for the three-dimensional steady flow in the nearfield of a transverse jet.
- To investigate the dominant instability of this flow, focusing on the impact of crossflow.
Main Methods:
- Utilized an asymptotic expansion based on the ratio of crossflow velocity to jet velocity (lambda << 1).
- Extended inviscid vortex sheet analysis to include viscous shear layers.
- Performed a stability analysis on the resulting uniformly valid solution.
Main Results:
- Identified an induced axial flow due to vorticity generated in viscous shear layers.
- Quantified the effect of crossflow on the dominant instability mode.
- Observed an increase in characteristic frequency and growth rate with increasing lambda.
Conclusions:
- The theoretical model provides a more accurate representation of transverse jet nearfield flow.
- Crossflow significantly influences jet instability, increasing its frequency and growth rate.
- Results are in qualitative agreement with experimental observations, validating the theoretical approach.
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