scholarly journals The Effects of Trapezoidal Groove on a Self-Acting Fluid-Lubricated Herringbone Grooves Journal Bearing

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jun Liu ◽  
Yoshihiro Mochimaru
Keyword(s):  
Journal Bearing ◽  
Load Capacity ◽  
Friction Torque ◽  
Cross Sectional ◽  
Groove Shape ◽  
Shape Effects ◽  
Sectional Shape ◽  
Herringbone Grooves

As a self-acting fluid-lubricated herringbone grooves journal bearing, a trapezoidal cross-sectional shape of grooves is considered. Trapezoidal groove shape effects on its bearing characteristics such as variations of load capacity, attitude, and friction torque for various trapezoidal angle of groove are determined.

scholarly journals Effect of Groove Shape on Head Loss and Filtration Performance of Disc Filters

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1683
Author(s):  
Sang-ik Lee ◽  
Jin-Yong Choi ◽  
Won Choi
Keyword(s):  
Performance Test ◽  
Filter Design ◽  
Head Loss ◽  
Sectional Area ◽  
Cross Sectional ◽  
Loss Analysis ◽  
Groove Shape ◽  
Filtration Performance ◽  
Sectional Shape ◽  
The Relationship

To analyze the effect of a groove cross-sectional shape on disc filters, a head loss analysis and filtration performance test were conducted using disc filters with different groove shapes (semi-elliptical- and trapezoidal-shaped grooves). Furthermore, the groove shapes were analyzed using field emission scanning electron microscopy and the relationship between flow rate and head loss was derived from the head loss test. Even if the filters were designed with the same mesh standard, the sectional areas of the grooves were different depending on the shape. Therefore, the head loss was compared under the condition that the grooves have the same sectional area by applying the relationship between head loss and sectional area, and a smaller head loss was observed in the semi-elliptical-shaped groove. Additionally, the semi-elliptical-groove-shaped disc filter was evaluated to sufficiently filter the soil particles corresponding to the 120 mesh standard. Therefore, an optimum disc filter can be designed by considering the cross-sectional shape of the disc groove to reduce energy consumption and provide stable filtration. The elliptical groove shape, which is hydraulically advantageous, is preferred for the disc filter design.

Behavior of High Strength Hybrid Reinforcement Concrete Beams

2020 ◽  
Vol 12 (7) ◽  
Author(s):  
Khanda Ali Al-Billbassi ◽  
◽  
Mushriq Fuad Kadhim Al-Shamaa ◽  
Keyword(s):  
Residual Strength ◽  
Ultimate Load ◽  
Steel Fiber ◽  
Load Capacity ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Ultimate Load Capacity ◽  
Cross Sectional ◽  
Sectional Shape

Six proposed simply supported high strength-steel fiber reinforced concrete (HS-SFRC) beams reinforced with FRP (fiber reinforced polymer) rebars were numerically tested by finite element method using ABAQUS software to investigate their behavior under the flexural failure. The beams were divided into two groups depending on their cross sectional shape. Group A consisted of four trapezoidal beams with dimensions of (height 200 mm, top width 250 mm, and bottom width 125 mm), while group B consisted of two rectangular beams with dimensions of (125 ×200) mm. All specimens have same total length of 1500 mm, and they were also considered to be made of same high strength concrete designed material with 1% volume fraction of steel fiber. Different types and ratios of FRP rebar were used to reinforce these test beams. The study’s principle variables were the amount and type of flexural reinforcement (glass FRP and basalt FRP) and beam cross-sectional shape (rectangular and trapezoidal). The load-deflection behavior and ultimate load capacity of the beams were studied and compared with one another under flexural test with symmetrical two-point loading. The results show that increasing the reinforcement ratio resulted in higher post cracking flexural stiffness, and higher residual strength, as well as caused an increase in the first cracking load and ultimate load capacity ranged from 3 to 16.9%, and 4.6 to 7.3% respectively. When the GFRP rebars replaced by BFRP, the overall beams flexural performance showed outstanding improvements. Moreover the results indicate that increasing the top width of the beam cross section led to a significant enhancement in the first crack load ranged from 16 to 32.4%, also a remarkable increases in the ultimate load capacity in the range of 35.5 to 35.8% were indicated in the trapezoidal beams compared to rectangular beams. However the results show that the deflections were similar and were approximately 1.07–1.54 mm for all test beams. It is worth noting that the general flexural behavior of all the test beams indicated a ductile behavior with a gradual reduction in strength and high residual strength pre to failure due to proposing steel fiber presence.

Cross-Sectional Shape Effects of Gate-All-Around Nanowire Field-Effect Transistors

2015 ◽  
Vol 12 (12) ◽  
pp. 5171-5178
Author(s):  
Hao Wang ◽  
Sheng Chang ◽  
Jin He ◽  
Qijun Huang ◽  
Gaofeng Wang
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Cross Sectional ◽  
Shape Effects ◽  
Sectional Shape

scholarly journals Pressure Distributions Generated along a Self-Acting Fluid-Lubricated Herringbone-Grooved Journal Bearing with Trapezoidal Groove

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
Jun Liu ◽  
Yoshihiro Mochimaru
Keyword(s):  
Journal Bearing ◽  
Load Capacity ◽  
Friction Torque ◽  
Radial Load ◽  
Pressure Distributions ◽  
Numerical Studies

Numerical studies are carried out to investigate pressure distributions of a fluid-lubricated herringbone-grooved journal bearing with trapezoidal grooves of various angles. Additionally, the optimal trapezoidal groove geometry is discussed in terms of the radial load capacity and friction torque.

On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa

1990 ◽  
Vol 48 (3) ◽  
pp. 566-567
Author(s):  
J.-F. Revol ◽  
Y. Van Daele ◽  
F. Gaill
Keyword(s):  
Contrast Imaging ◽  
Animal Kingdom ◽  
Bright Field ◽  
Field Mode ◽  
Cross Sectional ◽  
Ultrathin Sections ◽  
The Cross ◽  
Sectional Shape ◽  
Valonia Ventricosa ◽  
C Nmr

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.

Automated 3D measurement of fiber cross section morphology in handsheets

2012 ◽  
Vol 27 (2) ◽  
pp. 264-269 ◽  
Author(s):  
Christian Lorbach ◽  
Ulrich Hirn ◽  
Johannes Kritzinger ◽  
Wolfgang Bauer
Keyword(s):  
Image Analysis ◽  
Cross Section ◽  
Cross Sections ◽  
Image Plane ◽  
3D Measurement ◽  
Cross Sectional ◽  
Fiber Cross Section ◽  
Fiber Wall ◽  
Sectional Shape ◽  
Cross Section Geometry

Abstract We present a method for 3D measurement of fiber cross sectional morphology from handsheets. An automated procedure is used to acquire 3D datasets of fiber cross sectional images using an automated microtome and light microscopy. The fiber cross section geometry is extracted using digital image analysis. Simple sample preparation and highly automated image acquisition and image analysis are providing an efficient tool to analyze large samples. It is demonstrated that if fibers are tilted towards the image plane the images of fiber cross sections are always larger than the true fiber cross section geometry. In our analysis the tilting angles of the fibers to the image plane are measured. The resulting fiber cross sectional images are distorted to compensate the error due to fiber tilt, restoring the true fiber cross sectional shape. We use an approximated correction, the paper provides error estimates of the approximation. Measurement results for fiber wall thickness, fiber coarseness and fiber collapse are presented for one hardwood and one softwood pulp.

scholarly journals Improvement of Tilting-Pad Journal Bearing Operating Characteristics by Application of Eddy Grooves

Lubricants ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 18
Author(s):  
Eckhard Schüler ◽  
Olaf Berner
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Load Capacity ◽  
Fluid Film ◽  
Operating Characteristics ◽  
Fluid Film Bearings ◽  
Tilting Pad ◽  
Bearing Load ◽  
Bearing Loads ◽  
Tilting Pad Journal Bearing

In high speed, high load fluid-film bearings, the laminar-turbulent flow transition can lead to a considerable reduction of the maximum bearing temperatures, due to a homogenization of the fluid-film temperature in radial direction. Since this phenomenon only occurs significantly in large bearings or at very high sliding speeds, means to achieve the effect at lower speeds have been investigated in the past. This paper shows an experimental investigation of this effect and how it can be used for smaller bearings by optimized eddy grooves, machined into the bearing surface. The investigations were carried out on a Miba journal bearing test rig with Ø120 mm shaft diameter at speeds between 50 m/s–110 m/s and at specific bearing loads up to 4.0 MPa. To investigate the potential of this technology, additional temperature probes were installed at the crucial position directly in the sliding surface of an up-to-date tilting pad journal bearing. The results show that the achieved surface temperature reduction with the optimized eddy grooves is significant and represents a considerable enhancement of bearing load capacity. This increase in performance opens new options for the design of bearings and related turbomachinery applications.

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