String Flash-Boiling in Flashing and Non-Flashing Gasoline Direct Injection Simulations with Transient Needle Motion

E.T. Baldwin, R.O. Grover Jnr, D.J. Duke, K.E. Matusik, A.L. Kastengren, C.F. Powell, S.E. Parrish, D.P. Schmidt

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearch


A computational study was performed to investigate the influence of transient needle motion on gasoline direct injection (GDI) internal nozzle
ow and near-eld sprays. Simulations were conducted with a compressible
Eulerian flow solver modeling liquid, vapor, and non-condensable gas phases with a diuse 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 specied 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 m 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 actuate the injection. Needle wobble was found to have no measurable eect on the flow. Low needle lift is shown to
result in vapor generation as fuel rushes past the needle. And finally, the internal injector flow is shown tocontain many transient and interacting vortices which cause perturbations in the spray angle, fluctuations in the mass flux, and frequently result in string flash-boiling.
Original languageEnglish
Title of host publicationILASS-Americas 2016, 28th Annual Conference on Liquid Atomization and Spray Systems
Place of PublicationIrvine California USA
PublisherInstitute for Liquid Atomization and Spray Systems
Number of pages15
Publication statusPublished - 2016
Externally publishedYes
EventInternational Conference on Liquid Atomization and Spray Systems 2016: ILASS-Americas - The Henry Hotel, Dearborn , United States of America
Duration: 15 May 201618 May 2016


ConferenceInternational Conference on Liquid Atomization and Spray Systems 2016
Country/TerritoryUnited States of America

Cite this