scholarly journals Study on Periodic Pulsation Characteristics of Corn Grain in a Grain Cylinder during the Unloading Stage

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2314
Author(s):  
Han Tang ◽  
Changsu Xu ◽  
Xin Qi ◽  
Ziming Wang ◽  
Jinfeng Wang ◽  
...  
Keyword(s):  
Average Velocity ◽  
Simulation Analysis ◽  
Cone Angle ◽  
Laser Scanner ◽  
Grain Flow ◽  
Filling Method ◽  
Funnel Flow ◽  
Half Cone ◽  
Corn Grain ◽  
Half Cone Angle

The fluctuation effect of corn grain often occurs during the unloading stage. To accurately explore the periodic pulsation characteristics of corn grain during the unloading stage, a discrete model of corn grain was established, and the effectiveness of the discrete element method in simulating the corn grain unloading stage was verified by a 3D laser scanner and the “spherical particle filling method”. The grain cylinder was divided into six areas, and the periodic pulsation characteristics at different heights were explored through simulation tests. The results showed that the faster the average speed of corn grain changes in unit time, the more significant the periodic pulsation characteristics were as the height of grain unloading increased. The corn grain pulsateon in the grain cylinder exhibited gradual upward transmission and gradual amplification in the process of transmission. The average velocity decreased with increasing height. The direct cause of pulsation was the variation in the average stress between grain layers. Simulation analysis of grain unloading for different half cone angles of the grain cylinder was carried out. The change in corn grain average velocity over time in the area below 20 mm of the upper free surface was extracted. The results showed that the speed of the top corn grain increased with increasing the half cone angle, and the periodic pulsation phenomenon became more obvious with increasing the half cone angle at half cone angles of 30–65°. A half cone angle of 65–70° marked the critical state of corn grain flow changing from funnel flow to overall flow in the grain cylinder. This study provides a method for studying the periodic pulsation characteristics of different crops during the grain unloading stage and provides a technical reference for the safe design of grain unloading equipment.

Numerical Investigation of the Effect of Capsule Half-Cone Angle on a Supersonic Parachute System

2016 ◽  
Vol 29 (4) ◽  
pp. 06016001 ◽  
Author(s):  
Xiao-Peng Xue ◽  
Yusuke Nishiyama ◽  
Yoshiaki Nakamura ◽  
Koichi Mori ◽  
Chih-Yung Wen
Keyword(s):  
Numerical Investigation ◽  
Cone Angle ◽  
Parachute System ◽  
Half Cone ◽  
Half Cone Angle

Comparison of Two Complete Solutions in an Axisymmetric Extrusion With Experiment

1969 ◽  
Vol 91 (3) ◽  
pp. 543-548 ◽  
Author(s):  
A. H. Shabaik ◽  
E. G. Thomsen
Keyword(s):  
Strain Rate ◽  
Effective Strain ◽  
Cone Angle ◽  
Low Friction ◽  
First Approximation ◽  
Strain And Strain Rate ◽  
Conical Die ◽  
Stream Lines ◽  
Half Cone ◽  
Half Cone Angle

An upper-bound and a potential solution to a forward extrusion problem were compared with experimental results obtained by the visioplasticity method. The process consisted of extruding a 2-in-dia billet of preforged lead through a conical die having a half-cone angle of 45 deg under the condition of relatively low friction. The comparison was made for steady state stream lines, velocities, strain rate components, effective strain and strain rate, grid distortion, and stress distribution. It was found that the curves were generally of similar shape and that some differences existed in magnitude only. It is suggested that the theoretical solutions can be used to advantage to a first approximation in predicting all important variables.

scholarly journals Development technique for deep drawing without blank holder to produce circular cup of brass alloy

2015 ◽  
Vol 4 (1) ◽  
pp. 187 ◽  
Author(s):  
Ali Hassan Saleh ◽  
Ammer Khalaf Ali
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Deep Drawing ◽  
Cone Angle ◽  
Element Model ◽  
Drawing Ratio ◽  
Clearance Ratio ◽  
Blank Holder ◽  
Half Cone ◽  
Half Cone Angle

Of this technique compared to the conventional deep drawing is that the circular cup can be carried out in single action press with limit In this paper a new mechanism for deep drawing was proposed to produce circular cup from thin plate without blank holder. In this technique the die assembly includes punch, die and die-punch. A 2D axisymmetric finite element model was built using DEFORM software. Effect of die geometry (half- cone angle) on maximum load, thickness distribution, strain distribution and effect of clearance ratio between punch and (die-punch) on the wrinkling of the cup were investigated. Three half-cone angles of die (15o, 30o and 45o) were used for forming sheet metal of brass (CuZn37) which had initial thickness of (1mm) at four clearance ratio (c/t) for die of 30o half-cone angle. Finite element model results showed good agreement with experimental results. Die of 30o half-cone angle with clearance ratio (c/t) of 0.9 gave the best product without wrinkling. The main advantage drawing ratio (LDR) of 1.86 and blank diameter to blank thickness ratio (d/t) < 86.

scholarly journals Experimental Investigation of the Performance and Spray Characteristics of a Supersonic Two-Phase Flow Ejector with Different Structures

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1166 ◽  
Author(s):  
Shizhen Li ◽  
Wei Li ◽  
Yanjun Liu ◽  
Chen Ji ◽  
Jingzhi Zhang
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Fire Suppression ◽  
Cone Angle ◽  
Water Mist ◽  
Pulsation Period ◽  
Phase Flow ◽  
Two Phase ◽  
Half Cone ◽  
Half Cone Angle

A two-phase flow ejector is an important part of a water mist fire suppression system, and these devices have become a popular research topic in recent years. This paper proposes a supersonic ejector that aims to improve the efficiency of water mist fire suppression systems. The effects of ejector geometric parameters on the entrainment ratio (ER) were explored. The effects of primary flow pressure (PP) on the mixing process and flow phenomena were studied by a high-speed camera. The experimental results show that the ER first increases and then decreases with increasing PP. ER increases with increasing ejector area ratio (AR). The PP corresponding to the maximum ER of ejectors with a different nozzle exit position (NXP) is 3.6 bar. The ejector with an NXP of +1 and AR of 6 demonstrate the best performance, and the ER of this ejector reaches 36.29. The spray half-cone angle of the ejector increases with increasing ER, reaching a maximum value of 7.07°. The unstable atomization half-cone angle is mainly due to a two-phase flow pulsating phenomenon. The pulsation period is 10 ms. In the present study, a general rule that provides a reference for ejector design and selection was obtained through experiments.

Sampling of High-Quality Wet Steam from Steam Mains Operating at 11·4 Bar Pressure

1973 ◽  
Vol 187 (1) ◽  
pp. 381-393 ◽  
Author(s):  
D. J. Ryley ◽  
M. J. Holmes
Keyword(s):  
Static Pressure ◽  
Water Mass ◽  
Cone Angle ◽  
Wet Steam ◽  
High Quality ◽  
Flow Rates ◽  
Further Development ◽  
Half Cone ◽  
Steam Main ◽  
Half Cone Angle

A venturi device was employed to strip and entrain liquid from the wall of a 3 in (7·5 cm) diameter steam main prior to isokinetic sampling. By injecting heated water into dry steam the wetness fraction was controlled between 1 and 5 per cent. Venturi convergence half-cone angles of 20, 30, 40 and 50° were employed and steam flow rates varied from 360–730 kg/h (800–1600 1b/h). Observations were made of the distribution through the test section of static pressure, recovered temperature and film thickness (for pressure 3·8 bar (55 1b/in2 absolute) only). Sampling across a diameter showed that under the most advantageous conditions the ratio, aggregate mass of entrained water: mass of injected water did not exceed 23 per cent. The optimum venturi half-cone angle lay between 40 and 50°. While capable of further development, the stripping-sampling principle seems unlikely to lead to significant improvements in wet steam sampling for quality.

scholarly journals Optical pulling at macroscopic distances

2019 ◽  
Vol 5 (3) ◽  
pp. eaau7814 ◽  
Author(s):  
Xiao Li ◽  
Jun Chen ◽  
Zhifang Lin ◽  
Jack Ng
Keyword(s):  
Long Range ◽  
Light Propagation ◽  
Transverse Isotropy ◽  
Bessel Beam ◽  
Cone Angle ◽  
Antireflection Coatings ◽  
Light Interference ◽  
Scale Range ◽  
Half Cone ◽  
Half Cone Angle

Optical tractor beams, proposed in 2011 and experimentally demonstrated soon after, offer the ability to pull particles against light propagation. It has attracted much research and public interest. Yet, its limited microscopic-scale range severely restricts its applicability. The dilemma is that a long-range Bessel beam, the most accessible beam for optical traction, has a small half-cone angle, θ0, making pulling difficult. Here, by simultaneously using several novel and compatible mechanisms, including transverse isotropy, Snell’s law, antireflection coatings (or impedance-matched metamaterials), and light interference, we overcome this dilemma and achieve long-range optical pulling at θ0≈ 1°. The range is estimated to be 14 cm when using ~1 W of laser power. Thus, macroscopic optical pulling can be realized in a medium or in a vacuum, with good tolerance of the half-cone angle and the frequency of the light.

Sampling of High-Quality Wet Steam from Steam Mains Operating at 11·4 Bar Pressure

1973 ◽  
Vol 187 (1) ◽  
pp. 381-393 ◽  
Author(s):  
D. J. Ryley ◽  
M. J. Holmes
Keyword(s):  
Static Pressure ◽  
Water Mass ◽  
Cone Angle ◽  
Wet Steam ◽  
High Quality ◽  
Flow Rates ◽  
Further Development ◽  
Half Cone ◽  
Steam Main ◽  
Half Cone Angle

A venturi device was employed to strip and entrain liquid from the wall of a 3 in (7·5 cm) diameter steam main prior to isokinetic sampling. By injecting heated water into dry steam the wetness fraction was controlled between 1 and 5 per cent. Venturi convergence half-cone angles of 20, 30, 40 and 50° were employed and steam flow rates varied from 360–730 kg/h (800–1600 1b/h). Observations were made of the distribution through the test section of static pressure, recovered temperature and film thickness (for pressure 3·8 bar (55 1b/in2 absolute) only). Sampling across a diameter showed that under the most advantageous conditions the ratio, aggregate mass of entrained water: mass of injected water did not exceed 23 per cent. The optimum venturi half-cone angle lay between 40 and 50°. While capable of further development, the stripping-sampling principle seems unlikely to lead to significant improvements in wet steam sampling for quality.

CFD Analysis of the Effect of Surface Contour of Nose Cone of a Space Vehicle on the Thermal Field during Re-Entry

2018 ◽  
Vol 877 ◽  
pp. 460-464
Author(s):  
K.V. Sreenivas Rao ◽  
P. Sujan ◽  
H.S. Sachin
Keyword(s):  
Thermal Field ◽  
Cone Angle ◽  
Real Life ◽  
Space Vehicle ◽  
Frictional Resistance ◽  
Cfd Analysis ◽  
Surface Contour ◽  
Nose Cone ◽  
Half Cone ◽  
Half Cone Angle

When the space vehicle re-enters the earth’s atmosphere at a tremendous speed the frictional resistance creates enormous heat which may penetrate the vehicle leading to wreckage, if not dissipated to the surrounding. In the present study, CFD analysis of the thermal field generated on the surface of the solid model of the nose cone of the space vehicle is analyzed. Various configurations of the surface contour of the nose cone are considered to mimic the real life situation. The commercial CFD tool SolidWorks Flow Simulation module was used for the analysis. Four different surface contours were considered for the analysis of the temperature generated on its surface. The results indicate that the surface contour and re-entry velocity has a decided effect on the thermal field developed due to frictional resistance. Nose cone with larger half cone angle with small bluntness ratio offers greater resistance and hence lower temperature is generated compared to small half cone angle configuration.

Nonsimilar Boundary-Layer Heat Transfer of a Rotating Cone in Forced Flow

1967 ◽  
Vol 89 (2) ◽  
pp. 139-145 ◽  
Author(s):  
J. C. Y. Koh ◽  
J. F. Price
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Numerical Solutions ◽  
Cone Angle ◽  
Rotating Disk ◽  
Forced Flow ◽  
Degenerate Problem ◽  
Prandtl Numbers ◽  
Half Cone ◽  
Half Cone Angle

The nonsimilar boundary-layer flow and heat transfer of a cone rotating in a forced-flow field are investigated. Numerical solutions are shown for a half-cone angle of 53.5 deg with parameters (vw/ue)2 ranging from 0 to 20, and with Prandtl numbers from 0.2 to 10. With a half-cone angle of 90 deg (so that one has a rotating disk), the degenerate problem is solved in the same manner.

Influence of a helical pitch on orthoconic antiferroelectric liquid crystals performance

2011 ◽  
Vol 19 (1) ◽  
Author(s):  
N. Bennis ◽  
R. Dąrowski ◽  
W. Rejmer ◽  
A. Spadło ◽  
X. Quintana ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Dynamic Behaviour ◽  
Cone Angle ◽  
Helical Pitch ◽  
Antiferroelectric Liquid Crystals ◽  
Display Technology ◽  
Half Cone ◽  
Good Contrast ◽  
Half Cone Angle

AbstractOrthoconic antiferroelectric liquid crystals, whose half cone angle is 45°, are of interest in display technology because they are capable of providing greyscale in passively addressing waveform while exhibiting very good contrast. However, orthoconic antiferroelectrics having short pitch are difficult to be aligned, this makes surface stabilized alignment unfeasible. In this case, dynamic behaviour is usually poor, avoiding electronic addressing with standard electronics. In this work, we report the helical pitch measurements of OAFLC mixtures and we compare electrooptical performance of high and low pitch OAFLCs.

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