scholarly journals Effect of Swirl Plates on Volumetric Discharge Rate and Spray Characteristics of Hollow Cone Nozzles

2019 ◽  
pp. 103-110
Author(s):  
Bahadır Sayıncı ◽  
Rüçhan Çömlek ◽  
Bünyamin Demir ◽  
Mustafa Çomaklı
Fuel ◽  
2020 ◽  
Vol 272 ◽  
pp. 117710
Author(s):  
Hao Wu ◽  
Fujun Zhang ◽  
Zhenyu Zhang ◽  
Hongli Gao

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
A. Hussein ◽  
M. Hafiz ◽  
H. Rashid ◽  
A. Halim ◽  
W. Wisnoe ◽  
...  

An experimental work to investigate the swirl spray characteristics that emanates from hollow–cone and solid–cone spray simplex atomizers is presented. Main objective of the research is to investigate the spray characteristics, i.e. spray breakup length, discharge coefficient and spray cone angle at different nozzle orifice diameter and injection pressure. Discharge coefficient is almost uninfluenced by the operating Reynolds number. This test also reveals that both breakup length and spray cone angle increases as orifice diameter is increased. Higher injection pressure leads to shorter breakup length and wider spray cone angle.


Author(s):  
William Krakow

An electronic device has been constructed which manipulates the primary beam in the conventional transmission microscope to illuminate a specimen under a variety of virtual condenser aperture conditions. The device uses the existing tilt coils of the microscope, and modulates the D.C. signals to both x and y tilt directions simultaneously with various waveforms to produce Lissajous figures in the back-focal plane of the objective lens. Electron diffraction patterns can be recorded which reflect the manner in which the direct beam is tilted during exposure of a micrograph. The device has been utilized mainly for the hollow cone imaging mode where the device provides a microscope transfer function without zeros in all spatial directions and has produced high resolution images which are also free from the effect of chromatic aberration. A standard second condenser aperture is employed and the width of the cone annulus is readily controlled by defocusing the second condenser lens.


Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.


Author(s):  
O.L. Krivanek ◽  
M.L. Leber

Three-fold astigmatism resembles regular astigmatism, but it has 3-fold rather than 2-fold symmetry. Its contribution to the aberration function χ(q) can be written as:where A3 is the coefficient of 3-fold astigmatism, λ is the electron wavelength, q is the spatial frequency, ϕ the azimuthal angle (ϕ = tan-1 (qy/qx)), and ϕ3 the direction of the astigmatism.Three-fold astigmatism is responsible for the “star of Mercedes” aberration figure that one obtains from intermediate lenses once their two-fold astigmatism has been corrected. Its effects have been observed when the beam is tilted in a hollow cone over a wide range of angles, and there is evidence for it in high resolution images of a small probe obtained in a field emission gun TEM/STEM instrument. It was also expected to be a major aberration in sextupole-based Cs correctors, and ways were being developed for dealing with it on Cs-corrected STEMs.


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