1 / 1

Ultrafast X-ray Study of Swirling Hollow-Cone Sprays in the Near-Field

Ultrafast X-ray Study of Swirling Hollow-Cone Sprays in the Near-Field. Advanced Photon Source, Argonne National Laboratory, US. Objectives. Ultrafast X-ray Phase-Enhanced Imaging. High Energy X-ray : 9.62keV.

ania
Download Presentation

Ultrafast X-ray Study of Swirling Hollow-Cone Sprays in the Near-Field

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Ultrafast X-ray Study of Swirling Hollow-Cone Sprays in the Near-Field Advanced Photon Source, Argonne National Laboratory, US Objectives Ultrafast X-ray Phase-Enhanced Imaging High Energy X-ray : 9.62keV • Interpretation of near-field flow development of swirling hollow-cone sprays • Physical insight on various types of breakups and atomization process Temporal Resolution : 150ps Spatial Resolution < 1mm Temporal Spray Development Pinj= 2 MPa, Ambient Gas = N2, Fuel = Gasoline Calibration Fluid (Viscor 16BR) * Setup in XOR 7ID-B in APS, ANL Outward-Opening Swirl Injector A B C X-ray Tomography from APS, ANL Nozzle Structure (taken using x-ray phase-enhanced imaging) Opening -‘Skirts’ Opening -‘Instability Waves’ Steady – ‘Turbulent Flow from High Swirl’ D W. Caiet al., Appl. Phys. Lett. 83, 1671 (2003) Visible Light Image 1-5% Transmission at 1 mm location Pinj= 2 MPa Steady-state White-Light 11 ns Exposure 1mm Closing – ‘Streaks from Weakened Swirl’ A. Opening – ‘Skirts’ B. Opening – ‘Instability Waves’ Pinj= 2 MPa Droplet Sizes : 41 ~ 67 m Re Dependency Wavelength : 40 m 500 m 500 m Analyzed from non-swirl hollow spray Pinj= 7 MPa Droplet Sizes : 35 ~ 50 m Wavelength : 26 m 500 m Pinj= 5 MPa, 80 s ASOI Pinj= 7 MPa 120 s ASOI Pinj= 2 MPa 150 s ASOI • Low velocity laminar-like flow before swirl motion • Dictated by transient pressure and velocity • during needle opening • Skirt  Ligaments  Droplets • High injection pressures form thin and long • ligaments, and smaller droplets • Instability waves, an indicator of laminar to turbulence transition, appear on the sheet. • The wavelengths are dependent to Re. C. Steady – ‘Turbulent Flow from Strong Swirl’ D. Closing – ‘Streaks from Weakened Swirl’ Pinj= 2 MPa, 1.0 ms Probability of Feature Size 500 m 1 mm Number of Streaks at Dotted Boxes Pinj= 5 MPa, 1.19 ms 2 MPa 5 MPa 7 MPa Pinj= 2 MPa Pinj= 7 MPa Pinj= 7 MPa, 1.19 ms • Turbulent flow from nozzle exit from strong swirl flow • Ligaments, droplets and bubbles at downstream • Decrease in feature size at higher injection pressure • Increase in feature density at higher injection pressure • Streaks with less turbulent flow from weakened swirl • Increase in number of streaks at higher injection pressure •  Streaks are from hydrodynamic instability • Concluding Remarks • Hollow-cone swirl spray showed four representative stages of flow development with time: (1) skirts and (2) instability waves during opening, (3) turbulent flow from strong-swirl at steady-state and (4) streaks from weakened swirl during closing. • Instability wavelengths, ligament and droplet sizes decrease and number of streaks increases with increase in injection pressure.

More Related