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Title: String flash-boiling in gasoline direct injection simulations with transient needle motion

A computational study was performed to investigate the influence of transient needle motion on gasoline direct injection (GDI) internal nozzle flow and near-field sprays. Simulations were conducted with a compressible Eulerian flow solver modeling liquid, vapor, and non-condensable gas phases with a diffuse interface. Variable rate generation and condensation of fuel vapor were captured using the homogeneous relaxation model (HRM). The non-flashing (spray G) and flashing (spray G2) conditions specified by the Engine Combustion Network were modeled using the nominal spray G nozzle geometry and transient needle lift and wobble were based upon ensemble averaged x-ray imaging preformed at Argonne National Lab. The minimum needle lift simulated was 5 μm and dynamic mesh motion was achieved with Laplacian smoothing. The results were qualitatively validated against experimental imaging and the experimental rate of injection profile was captured accurately using pressure boundary conditions and needle motion to actu- ate the injection. Needle wobble was found to have no measurable effect on the flow. Low needle lift is shown to result in vapor generation as fuel rushes past the needle. In conclusion, the internal injector flow is shown to contain many transient and interacting vortices which cause perturbations in the spray angle, fluctuationsmore » in the mass flux, and frequently result in string flash-boiling.« less
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  1. Univ. of Massachusetts, Amherst, MA (United States)
  2. General Motors Research and Development, Warren, MI (United States)
  3. Argonne National Lab. (ANL), Lemont, IL (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
International Journal of Multiphase Flow
Additional Journal Information:
Journal Volume: 87; Journal Issue: C; Journal ID: ISSN 0301-9322
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
General Motors, R & D; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Scientific User Facilities Division
Country of Publication:
United States
33 ADVANCED PROPULSION SYSTEMS; 42 ENGINEERING; Gasoline direct injection; Flash-boiling; Diffuse interface; CFD; Openfoam
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1359200