X-Ray Propagation-Based Phase-Enhanced Imaging of Fuel Injectors

2001 ◽  
Author(s):  
Wah-Keat Lee ◽  
Kamel Fezzaa ◽  
Jin Wang
Keyword(s):  
Conventional Radiography ◽  
Fuel Injector ◽  
Line Geometry ◽  
Time Resolved ◽  
Fuel Injectors ◽  
X Ray ◽  
Contrast Mechanism ◽  
Time Resolved Imaging ◽  
Photon Source ◽  
Enhanced Imaging

Abstract X-ray propagation-based phase-enhanced imaging is a powerful new technique that uses the x-ray beam coherence to greatly improve the image contrast. With the high x-ray beam brilliance (or alternately, good beam coherence) available at third-generation synchrotron sources, such as the Advanced Photon Source (APS), propagation-based phase-enhanced imaging can be easily accomplished. The power of this technique lies in its simplicity — it is an in-line geometry and requires little or no beam manipulation, and it works over the entire range of accessible energies (10–100 keV). Unlike conventional radiography, its contrast mechanism is mostly due to Fresnel diffraction and not absorption. The technique works for soft biological samples, as well as thick (several millimeters) stainless-steel samples. In this paper, we demonstrate the utility of this technique to study several fuel injectors and compare the results with conventional absorption radiography. The possibility of extending this technique to time-resolved imaging studies on the fuel injector will be discussed.

The Effects of Diesel Injector Needle Motion on Spray Structure

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
C. F. Powell ◽  
A. L. Kastengren ◽  
Z. Liu ◽  
K. Fezzaa
Keyword(s):  
Three Dimensional ◽  
Cfd Modeling ◽  
Needle Valve ◽  
Time Resolved ◽  
Fuel Injectors ◽  
Fuel Distribution ◽  
X Ray ◽  
Fuel Flow ◽  
Dependent Flow ◽  
Time Resolved Imaging

The internal structure of diesel fuel injectors is known to have a significant impact on the steady-state fuel distribution within the spray. However, little experimental or computational work has been performed on the dynamics of fuel injectors. Recent studies have shown that it is possible to measure the three-dimensional geometry of the injector nozzle, and to track changes in that geometry as the needle opens and closes in real time. This has enabled the dynamics of the injector to be compared with the dynamics of the spray, and allows computational fluid dynamics (CFD) simulations to use realistic time-dependent flow passage geometries. In this study, X-ray phase-enhanced imaging has been used to perform time-resolved imaging of the needle seat area in several common-rail diesel injection nozzles. The fuel distributions of the sprays emitted by these injectors were also studied with fast X-ray radiography. Correlations between eccentric motions of the injector needle valve and oscillations in the fuel density as it emerges from the nozzle are examined. CFD modeling is used to interpret the effect of needle motion on fuel flow.

The Effects of Diesel Injector Needle Motion on Spray Structure

2009 ◽  
Author(s):  
C. F. Powell ◽  
A. L. Kastengren ◽  
Z. Liu ◽  
K. Fezzaa
Keyword(s):  
Three Dimensional ◽  
Cfd Modeling ◽  
Needle Valve ◽  
Time Resolved ◽  
Fuel Injectors ◽  
Fuel Distribution ◽  
X Ray ◽  
Fuel Flow ◽  
Dependent Flow ◽  
Time Resolved Imaging

The internal structure of diesel fuel injectors is known to have a significant impact on the steady-state fuel distribution within the spray. However, little experimental or computational work has been performed on the dynamics of fuel injectors. Recent studies have shown that it is possible to measure the three-dimensional geometry of the injector nozzle, and to track changes in that geometry as the needle opens and closes in real time. This has enabled the dynamics of the injector to be compared with the dynamics of the spray, and allows CFD simulations to use realistic time-dependent flow passage geometries. In this study, x-ray phase-enhanced imaging has been used to perform time-resolved imaging of the needle seat area in several common-rail diesel injection nozzles. The fuel distributions of the sprays emitted by these injectors were also studied with fast x-ray radiography. Correlations between eccentric motions of the injector needle valve and oscillations in the fuel density as it emerges from the nozzle are examined. CFD modeling is used to interpret the effect of needle motion on fuel flow.

Time-Resolved Imaging of Correlation-Driven Charge Migration in Light-Induced Molecular Magnets by X-ray Scattering

2020 ◽  
Author(s):  
Jean-Christophe Tremblay ◽  
Gunter Hermann ◽  
Vincent Pohl ◽  
Gopal Dixit
Keyword(s):  
Molecular Magnets ◽  
Time Dependent ◽  
Electron Dynamics ◽  
Charge Migration ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Induced Charge ◽  
Time Resolved Imaging ◽  
The Stability

In this contribution, we investigate the effect of correlation-induced charge migration on the stability of light-induced molecular magnets. Laser-driven electron dynamics is simulated using density-matrix based time-dependent configuration interaction. The...

scholarly journals A full-field transmission x-ray microscope for time-resolved imaging of magnetic nanostructures

2016 ◽  
Author(s):  
J. Ewald ◽  
P. Wessels ◽  
M. Wieland ◽  
T. Nisius ◽  
A. Vogel ◽  
...  
Keyword(s):  
Magnetic Nanostructures ◽  
Time Resolved ◽  
Full Field ◽  
X Ray ◽  
Time Resolved Imaging

Comparison of URANS and LES CFD Methodologies for Air Swirl Fuel Injectors

2008 ◽  
Author(s):  
David Dunham ◽  
Adrian Spencer ◽  
James J. McGuirk ◽  
Mehriar Dianat
Keyword(s):  
Large Scale ◽  
Temporal Dynamics ◽  
Navier Stokes ◽  
Test Case ◽  
Fuel Injector ◽  
Time Resolved ◽  
Fuel Injectors ◽  
Vortex Pattern ◽  
Precessing Vortex Core ◽  
Flow Configurations

It is well documented that various large scale quasi-periodic flow structures, such as a Precessing Vortex Core (PVC) and multiple vortex helical instabilities, are present in the swirling flows typical of air swirl fuel injectors. Prediction of these phenomena requires time-resolved computational methods. The focus of the present work was to compare the performance and cost implications of two CFD methodologies — Unsteady Reynolds Averaged Navier Stokes (URANS – using a k-ε model) and Large Eddy Simulation (LES) for such flows. The test case was a single stream radial swirler geometry, which has been the subject of extensive experimental investigation. Both approaches captured the gross (time-mean) features of strongly swirling confined flows in reasonable agreement with experiment. The temporal dynamics of the quadruple vortex pattern emanating from within the swirler and observed experimentally were successfully predicted by LES, but not by URANS. Spectral analysis of two flow configurations (with and without a central jet), revealed various coherent frequencies embedded within the broadband turbulent frequency range. LES reproduced these characteristics, in excellent agreement with experimental data, whereas URANS predicted the presence of coherent motions but at incorrect amplitudes and frequencies. For the no jet case, LES-predicted spectral data indicated the occurrence of a PVC, which was also observed experimentally for this flow condition; the URANS solution failed to reproduce this measured trend. On the evidence of this study, although k-ε based URANS offers considerable computational savings, its inability to capture the temporal characteristics of the flows studied here sufficiently accurately suggests that only LES-based CFD, which captures the stochastic nature of the turbulence much more faithfully, is to be recommended for fuel injector flows.

scholarly journals Time-resolved 3D imaging of two-phase fluid flow inside a steel fuel injector using synchrotron X-ray tomography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aniket Tekawade ◽  
Brandon A. Sforzo ◽  
Katarzyna E. Matusik ◽  
Kamel Fezzaa ◽  
Alan L. Kastengren ◽  
...  
Keyword(s):  
Fluid Flow ◽  
3D Imaging ◽  
Fuel Injector ◽  
Two Phase ◽  
Time Resolved ◽  
X Ray ◽  
Phase Fluid

scholarly journals Capabilities of time-resolved X-ray excited optical luminescence of the Taiwan Photon Source 23A X-ray nanoprobe beamline

2020 ◽  
Vol 27 (1) ◽  
pp. 217-221
Author(s):  
Bi-Hsuan Lin ◽  
Yu-Hao Wu ◽  
Xiao-Yun Li ◽  
Hsu-Cheng Hsu ◽  
Yu-Cheng Chiu ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Decay Time ◽  
Streak Camera ◽  
Photonic Materials ◽  
Experimental Conditions ◽  
Time Resolved ◽  
X Ray ◽  
Optical Luminescence ◽  
Excellent Spatial Resolution ◽  
Photon Source

Time-resolved X-ray excited optical luminescence (TR-XEOL) was developed successfully for the 23A X-ray nanoprobe beamline located at the Taiwan Photon Source (TPS). The advantages of the TR-XEOL facility include (i) a nano-focused X-ray beam (<60 nm) with excellent spatial resolution and (ii) a streak camera that can simultaneously record the XEOL spectrum and decay time. Three time spans, including normal (30 ps to 2 ns), hybrid (30 ps to 310 ns) and single (30 ps to 1.72 µs) bunch modes, are available at the TPS, which can fulfil different experimental conditions involving samples with various lifetimes. It is anticipated that TR-XEOL at the TPS X-ray nanoprobe could provide great characterization capabilities for investigating the dynamics of photonic materials.

Sign in / Sign up

Export Citation Format

Share Document