Atomization of an Aircraft Engine Liquid Fuel Jet in a Crossflow
Arizona State University
Visualization of the breakup of an aircraft engine turbulent liquid fuel jet injected into a compressed turbulent gaseous cross-stream.
We present a visualization of the primary atomization of a turbulent liquid fuel jet injected into a compressed turbulent gaseous cross-stream representative of aircraft gas turbine engines and augmentors. Detailed numerical simulation results were obtained using a finite volume, balanced force, incompressible LES/DNS flow solver. Grid resolution in the primary atomization region is a constant 64 grid points per injector diameter in the flow solver, and 128 grid points per injector diameter in the level set solver, resulting in grid sizes of 110 million control volumes for the flow solver and a theoretical maximum of 6.7 billion nodes for the level set solver. We employ a hybrid Eulerian/Lagrangian approach for the liquid in that broken off, small, nearly spherical liquid drops tracked by the Eulerian level set approach are transferred into Lagrangian point particles to capture the evolution of the liquid spray downstream of the primary atomization region.
The simulation results clearly show the simultaneous presence of two distinct breakup modes. While the main column of the jet is subject to a wavy instability mode, resulting in the formation of bags that break under the influence of the cross stream flow at the end of the liquid core, ligaments are formed on the sides of the jet near the injector exit that stretch and break. The flow in the wake of the bending liquid jet is characterized by strong turbulence. Comparison of the simulation results to experimental data show that mean jet penetration is in excellent agreement to experimental correlations and drop size distributions converge under grid refinement (M. Herrmann, J. Eng. Gas Turb. Power, 132(2), 2010).
This work is funded in part by Cascade Technologies Inc under NavAir SBIR N07-046 and supported by Arizona State University's HPC Initiative.
M. Herrmann, J. Eng. Gas Turb. Power, 132(2), 2010.
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Reporters may freely use these images. Credit: S. Rana & M. Herrmann, Arizona State University (2010).