Assessing the role of surface tension force to the simulation of sub-grid scale interaction of turbulence and cavitation under realistic diesel injection conditions

Research output: Chapter in Book/Conference proceeding with ISSN or ISBNConference contribution with ISSN or ISBN

Abstract

With the ever increasing operating pressures of modern fuel injectors, the spray formation processes are increasingly influenced by the inception and development of cavitation inside the injector orifices and nozzle. The turbulent effects that contribute to the jet formation and subsequent break-up processes are enhanced by the growth and destructive collapse of cavitation bubbles. Turbulent effects generated by cavitation are resisted by viscosity and surface tension forces formed at the interface between the two phases. Sub-grid scale LES turbulence models are largely viscosity based and only assume flows in single phase. In the current work a systematic variation of the turbulence models and their constants were performed to investigate the influence of surface tension on the cavitation cloud topology as well as on the interaction of cavitation and turbulence. The objective is to extend our understanding of the shortcomings of the assumptions made in current SGS turbulence models and highlight the necessary modifications needed to consider high-velocity two-phase flows of direct fuel injectors. An OpenFOAM based solver (cavitatingFoam) was modified to account for interfacial phenomena such as surface tension. Results are compared with published data for a single injector nozzle and a sensitivity analysis is performed based on the fluid properties. Interaction between the cavitation layer and the near-wall was also investigated, where flow characteristics and grid refinement of the near-wall grid were adjusted to observe any transitional effects.

Original languageEnglish
Title of host publicationInstitution of Mechanical Engineers - Fuel Systems Engines Conference 2018
PublisherMechanical Engineering for the Institution of Mechanical Engineers
Pages175-188
Number of pages14
ISBN (Electronic)9781510883482
ISBN (Print)9781510883482
Publication statusPublished - 1 Jan 2019
EventFuel Systems Engines Conference 2018 - London, United Kingdom
Duration: 4 Dec 20185 Dec 2018

Publication series

NameInstitution of Mechanical Engineers - Fuel Systems Engines Conference 2018

Conference

ConferenceFuel Systems Engines Conference 2018
CountryUnited Kingdom
CityLondon
Period4/12/185/12/18

Keywords

  • Cavitation
  • LES
  • Small Scale turbulence
  • Volume of Fluid

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