Corrosion rates of stainless steel under shear stress measured by a novel parallel-plate flow chamber

2006 ◽  
Vol 76B (2) ◽  
pp. 273-280 ◽  
Author(s):  
Regina L. W. Messer ◽  
John Mickalonis ◽  
Yolanda Adams ◽  
Wan Y. Tseng
Keyword(s):  
Stainless Steel ◽  
Shear Stress ◽  
Parallel Plate ◽  
Flow Chamber ◽  
Parallel Plate Flow Chamber ◽  
Corrosion Rates

Wall Shear Stress Determination in a Small-Scale Parallel Plate Flow Chamber Using Laser Doppler Velocimetry Under Laminar, Pulsatile and Low-Reynolds Number Turbulent Flows

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Hamed Avari ◽  
Kem A. Rogers ◽  
Eric Savory
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Laser Doppler Velocimetry ◽  
Parallel Plate ◽  
Flow Chamber ◽  
Laser Doppler ◽  
Small Scale ◽  
Doppler Velocimetry ◽  
Flow Conditions ◽  
Parallel Plate Flow Chamber

The parallel plate flow chamber (PPFC) has gained popularity due to its applications in fields such as biological tissue engineering. However, most of the studies using PPFC refer to theoretical relations for estimating the wall shear stress (WSS) and, hence, the accuracy of such quantifications remains elusive for anything other than steady laminar flow. In the current study, a laser Doppler velocimetry (LDV) method was used to quantify the flow in a PPFC (H = 1.8 mm × W = 17.5 mm, Dh = 3.26 mm, aspect ratio = 9.72) under steady Re = 990, laminar pulsatile (carotid Re0-mean = 282 as well as a non-zero-mean sinusoidal Re0-mean = 45 pulse) and low-Re turbulent Re = 2750 flow conditions. A mini-LDV probe was applied, and the absolute location of the LDV measuring volume with the respect to the wall was determined using a signal monitoring technique with uncertainties being around ±27 μm. The uniformity of the flow across the span of the channel, as well as the WSS assessment for all the flow conditions, was measured with the uncertainties all being less than 16%. At least two points within the viscous sublayer of the low-Re turbulent flow were measured (with the y+ for the first point < 3) and the WSS was determined using two methods with the differences between the two methods being within 5%. This paper for the first time presents the experimental determination of WSS using LDV in a small-scale PPFC under various flow conditions, the challenges associated with each condition, and a comparison between the cases. The present data will be useful for those conducting biological or numerical modeling studies using such devices.

scholarly journals A fluid–structure interaction model to characterize bone cell stimulation in parallel-plate flow chamber systems

2013 ◽  
Vol 10 (81) ◽  
pp. 20120900 ◽  
Author(s):  
T. J. Vaughan ◽  
M. G. Haugh ◽  
L. M. McNamara
Keyword(s):  
Shear Stress ◽  
Fluid Flow ◽  
Parallel Plate ◽  
Bone Cells ◽  
Mechanical Stimulus ◽  
Flow Chamber ◽  
Parallel Plate Flow Chamber ◽  
Structure Interaction

Bone continuously adapts its internal structure to accommodate the functional demands of its mechanical environment and strain-induced flow of interstitial fluid is believed to be the primary mediator of mechanical stimuli to bone cells in vivo. In vitro investigations have shown that bone cells produce important biochemical signals in response to fluid flow applied using parallel-plate flow chamber (PPFC) systems. However, the exact mechanical stimulus experienced by the cells within these systems remains unclear. To fully understand this behaviour represents a most challenging multi-physics problem involving the interaction between deformable cellular structures and adjacent fluid flows. In this study, we use a fluid–structure interaction computational approach to investigate the nature of the mechanical stimulus being applied to a single osteoblast cell under fluid flow within a PPFC system. The analysis decouples the contribution of pressure and shear stress on cellular deformation and for the first time highlights that cell strain under flow is dominated by the pressure in the PPFC system rather than the applied shear stress. Furthermore, it was found that strains imparted on the cell membrane were relatively low whereas significant strain amplification occurred at the cell–substrate interface. These results suggest that strain transfer through focal attachments at the base of the cell are the primary mediators of mechanical signals to the cell under flow in a PPFC system. Such information is vital in order to correctly interpret biological responses of bone cells under in vitro stimulation and elucidate the mechanisms associated with mechanotransduction in vivo .

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