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.

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.

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.

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 Time-resolved imaging of three-dimensional nanoscale magnetization dynamics

2020 ◽  
Vol 15 (5) ◽  
pp. 356-360 ◽  
Author(s):  
Claire Donnelly ◽  
Simone Finizio ◽  
Sebastian Gliga ◽  
Mirko Holler ◽  
Aleš Hrabec ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Magnetization Dynamics ◽  
Time Resolved ◽  
Time Resolved Imaging

Globule-Globule Interactions during Deformation in Semi-Solid Al-Cu Using Time-Resolved X-Ray Tomography

2012 ◽  
Vol 192-193 ◽  
pp. 179-184
Author(s):  
Kristina Maria Kareh ◽  
Peter D. Lee ◽  
Christopher M. Gourlay
Keyword(s):  
Solid Fraction ◽  
Three Dimensional ◽  
Solid Alloy ◽  
Three Dimensional Imaging ◽  
Time Resolved ◽  
X Ray ◽  
Analysis Techniques ◽  
Solid Deformation ◽  
Fundamental Understanding ◽  
Semi Solid

Optimising semi-solid processing and accurately modelling semi-solid deformation requires a fundamental understanding of the globule-scale mechanisms that cause the macroscopic rheological response. In this work, apparatus and analysis techniques are being developed for the time-resolved, three-dimensional imaging of semi-solid alloy deformation. This paper overviews synchrotron X-ray tomography results on globular Al-15wt%Cu deformed at 0.7 solid fraction using extrusion. The globule-globule interactions in response to load were quantified in terms of the response of individual globules with respect to globule translation, rotation, and deformation. The potential of time-resolved X-ray tomography in the study of semi-solid alloy deformation is then discussed.

Static Laue Diffraction Studies on Acetylcholinesterase

1998 ◽  
Vol 54 (6) ◽  
pp. 1359-1366 ◽  
Author(s):  
Raimond B. G. Ravelli ◽  
Mia L. Raves ◽  
Zhong Ren ◽  
Dominique Bourgeois ◽  
Michel Roth ◽  
...  
Keyword(s):  
Structural Change ◽  
Exposure Time ◽  
Active Site ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Reversible Inhibitor ◽  
Data Set ◽  
Time Resolved ◽  
X Ray ◽  
Density Maps

Acetylcholinesterase (AChE) is one of nature's fastest enzymes, despite the fact that its three-dimensional structure reveals its active site to be deeply sequestered within the molecule. This raises questions with respect to traffic of substrate to, and products from, the active site, which may be investigated by time-resolved crystallography. In order to address one aspect of the feasibility of performing time-resolved studies on AChE, a data set has been collected using the Laue technique on a trigonal crystal of Torpedo californica AChE soaked with the reversible inhibitor edrophonium, using a total X-ray exposure time of 24 ms. Electron-density maps obtained from the Laue data, which are of surprisingly good quality compared with similar maps from monochromatic data, show essentially the same features. They clearly reveal the bound ligand, as well as a structural change in the conformation of the active-site Ser200 induced upon binding.

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

scholarly journals Unveiling the spatial distribution of molecular coherences at conical intersections by covariance X-ray diffraction signals

2021 ◽  
Vol 118 (22) ◽  
pp. e2105046118
Author(s):  
Stefano M. Cavaletto ◽  
Daniel Keefer ◽  
Jérémy R. Rouxel ◽  
Flavia Aleotti ◽  
Francesco Segatta ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Three Dimensional ◽  
Laser Pulses ◽  
Conical Intersection ◽  
Conical Intersections ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Diffraction Imaging ◽  
The Rich

The outcomes and timescales of molecular nonadiabatic dynamics are decisively impacted by the quantum coherences generated at localized molecular regions. In time-resolved X-ray diffraction imaging, these coherences create distinct signatures via inelastic photon scattering, but they are buried under much stronger background elastic features. Here, we exploit the rich dynamical information encoded in the inelastic patterns, which we reveal by frequency-dispersed covariance ultrafast powder X-ray diffraction of stochastic X-ray free-electron laser pulses. This is demonstrated for the photoisomerization of azobenzene involving the passage through a conical intersection, where the nuclear wave packet branches and explores different quantum pathways. Snapshots of the coherence dynamics are obtained at high frequency shifts, not accessible with conventional diffraction measurements. These provide access to the timing and to the confined spatial distribution of the valence electrons directly involved in the conical intersection passage. This study can be extended to full three-dimensional imaging of conical intersections with ultrafast X-ray and electron diffraction.

scholarly journals Time-resolved in situ visualization of the structural response of zeolites during catalysis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinback Kang ◽  
Jerome Carnis ◽  
Dongjin Kim ◽  
Myungwoo Chung ◽  
Jaeseung Kim ◽  
...  
Keyword(s):  
Active Sites ◽  
Density Functional ◽  
Three Dimensional ◽  
Structural Response ◽  
Active Regions ◽  
Structural Deformation ◽  
Time Resolved ◽  
X Ray ◽  
Future Design

AbstractZeolites are three-dimensional aluminosilicates having unique properties from the size and connectivity of their sub-nanometer pores, the Si/Al ratio of the anionic framework, and the charge-balancing cations. The inhomogeneous distribution of the cations affects their catalytic performances because it influences the intra-crystalline diffusion rates of the reactants and products. However, the structural deformation regarding inhomogeneous active regions during the catalysis is not yet observed by conventional analytical tools. Here we employ in situ X-ray free electron laser-based time-resolved coherent X-ray diffraction imaging to investigate the internal deformations originating from the inhomogeneous Cu ion distributions in Cu-exchanged ZSM-5 zeolite crystals during the deoxygenation of nitrogen oxides with propene. We show that the interactions between the reactants and the active sites lead to an unusual strain distribution, confirmed by density functional theory simulations. These observations provide insights into the role of structural inhomogeneity in zeolites during catalysis and will assist the future design of zeolites for their applications.

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