517 Influence of hemolysis based on surface roughness and shear stress under highly viscous blood shear flow field

2010 ◽  
Vol 2010.18 (0) ◽  
pp. 145-146
Keyword(s):  
Surface Roughness ◽  
Shear Stress ◽  
Shear Flow ◽  
Flow Field

A Modified Average Reynolds Equation for Rough Bearings With Anisotropic Slip

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Hsiang-Chin Jao ◽  
Kuo-Ming Chang ◽  
Li-Ming Chu ◽  
Wang-Long Li
Keyword(s):  
Surface Roughness ◽  
Shear Stress ◽  
Shear Flow ◽  
Reynolds Equation ◽  
Slenderness Ratio ◽  
Atomic Scale ◽  
Stress Factors ◽  
Squeeze Film ◽  
Boundary Slip ◽  
Slip Conditions

A lubrication theory that includes the coupled effects of surface roughness and anisotropic slips is proposed. The anisotropic-slip phenomena originate from the microscale roughness at the atomic scale (microtexture) and surface properties of the lubricating surfaces. The lubricant flow between rough surfaces (texture) is defined as the flow in nominal film thickness multiplied by the flow factors. A modified average Reynolds equation (modified ARE) as well as the related factors (pressure and shear flow factors, and shear stress factors) is then derived. The present model can be applied to squeeze film problems for anisotropic-slip conditions and to sliding lubrication problems with restrictions to symmetric anisotropic-slip conditions (the two lubricating surfaces have the same principal slip lengths, i.e., b1x=b2x and b1y=b2y). The performance of journal bearings is discussed by solving the modified ARE numerically. Different slenderness ratios 5, 1, and 0.2 are considered to discuss the coupled effects of anisotropic slip and surface roughness. The results show that the existence of boundary slip can dilute the effects of surface roughness. The boundary slip tends to “smoothen” the bearings, i.e., the derived flow factors with slip effects deviate lesser from the values at smooth cases (pressure flow factors φxxp,φyyp=1; shear flow factors φxxs=0; and shear stress factors φf,φfp=1 and φfs=0) than no-slip one. The load ratio increases as the dimensionless slip length (B) decreases exception case is also discussed or the slenderness ratio (b/d) increases. By controlling the surface texture and properties, a bearing with desired performance can be designed.

scholarly journals Hemolysis due to Surface Roughness under Laminar Shear Flow Field

2007 ◽  
Vol 19 (Supplement) ◽  
pp. 73-73
Author(s):  
Yudai KAWAGUCHI ◽  
Osamu MARUYAMA ◽  
Masahiro NISHIDA ◽  
Takashi YAMANE ◽  
Bunshu NAGAI ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Shear Flow ◽  
Flow Field ◽  
Laminar Shear Flow ◽  
Laminar Shear

1010 Influence of hemolysis based on the surface roughness on the metal material under blood shear flow field

2009 ◽  
Vol 2009 (0) ◽  
pp. 271-272
Author(s):  
Osamu MARUYAMA ◽  
Jun-ya ABE ◽  
Masahiro NISHIDA ◽  
Takashi YAMANE ◽  
Ikuya OSHIMA ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Shear Flow ◽  
Flow Field ◽  
Metal Material

scholarly journals Experimental Study on the Shear-Flow Coupled Behavior of Tension Fractures Under Constant Normal Stiffness Boundary Conditions

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 57 ◽  
Author(s):  
Changsheng Wang ◽  
Yujing Jiang ◽  
Hengjie Luan ◽  
Jiankang Liu ◽  
Satoshi Sugimoto
Keyword(s):  
Surface Roughness ◽  
Shear Stress ◽  
Shear Flow ◽  
Boundary Conditions ◽  
Normal Stress ◽  
Growth Stage ◽  
Normal Stiffness ◽  
Peak Shear Stress ◽  
Hydraulic Aperture ◽  
Constant Normal Stiffness

This study experimentally investigated the effects of fracture surface roughness, normal stiffness, and initial normal stress on the shear-flow behavior of rough-walled rock fractures. A series of shear-flow tests were performed on two rough fractures, under various constant normal stiffness (CNS) boundary conditions. The results showed that the CNS boundary conditions have a significant influence on the mechanical and hydraulic behaviors of fractures, during shearing. The peak shear stress shows an increasing trend with the increases in the initial normal stress and fracture roughness. The residual shear stress increases with increasing the surface roughness, normal stiffness, and initial normal stress. The dilation of fracture is restrained more significantly under high normal stiffness and initial normal stress conditions. The hydraulic tests show that the evolutions of transmissivity and hydraulic aperture exhibit a three-stage behavior, during the shear process—a slight decrease stage due to the shear contraction, a fast growth stage due to shear dilation, and a slow growth stage due to the reduction rate of the mechanical aperture increment. The transmissivity and hydraulic aperture decreased, gradually, as the normal stiffness and initial normal stress increase.

scholarly journals Effect of Hemolysis due to Surface Roughness Level and Shear Stress under Shear Flow Condition

2008 ◽  
Vol 20 (Supplement) ◽  
pp. 91-91
Author(s):  
Osamu MARUYAMA ◽  
Yudai KAWAGUCHI ◽  
Koji MAIYA ◽  
Masahiro NISHIDA ◽  
Takashi YAMANE ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Shear Stress ◽  
Shear Flow ◽  
Flow Condition

Tracings of Behavior of Myoblasts Cultured Under Couette Type of Shear Flow Between Parallel Disks

2021 ◽  
Author(s):  
Shigehiro Hashimoto ◽  
Hiroki Yonezawa
Keyword(s):  
Shear Stress ◽  
Shear Flow ◽  
Rotating Disk ◽  
Time Lapse ◽  
Mechanical Stimuli ◽  
Parallel Disks ◽  
Before And After ◽  
A Cell

Abstract A cell deforms and migrates on the scaffold under mechanical stimuli in vivo. In this study, a cell with division during shear stress stimulation has been observed in vitro. Before and after division, both migration and deformation of each cell were analyzed. To make a Couette-type shear flow, the medium was sandwiched between parallel disks (the lower stationary culture-disc and the upper rotating disk) with a constant gap. The wall shear stress (1.5 Pa < τ < 2 Pa) on the surface of the lower culture plate was controlled by the rotational speed of the upper disc. Myoblasts (C2C12: mouse myoblast cell line) were used in the test. After cultivation without flow for 24 hours for adhesion of the cells to the lower disk, constant τ was applied to the cells in the incubator for 7 days. The behavior of each cell during shear was tracked by time-lapse images observed by an inverted phase contrast microscope placed in the incubator. Experimental results show that each cell tends to divide after higher activities: deformation and migration. The tendency is remarkable at the shear stress of 1.5 Pa.

Orientational Distributions of a Ferromagnetic Spherocylinder Particle in a Simple Shear Flow

2002 ◽  
Author(s):  
Masayuki Aoshima ◽  
Akira Satoh ◽  
Geoff N. Coverdale ◽  
Roy W. Chantrell
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Shear Flow ◽  
Flow Field ◽  
Simple Shear ◽  
Applied Magnetic Field ◽  
Spherical Particles ◽  
Simple Shear Flow ◽  
Microstructure Formation ◽  
Base Liquid

A ferrofluid is a suspension of ferromagnetic spherical particles in a base liquid (1), and is well known as a functional fluid which responds to an external magnetic field to give a large increase in the viscosity. Such a significant increase in the viscosity is due to the fact that chain-like clusters are formed owing to magnetostatic interactions between particles in an applied magnetic field. The microstructure formation offers a large resistance to a flow field that gives rise to a significant increase of the apparent viscosity (2).

Sign in / Sign up

Export Citation Format

Share Document