Microscale Flow Visualization

2002 ◽  
Author(s):  
David Sinton ◽  
Dongqing Li
Keyword(s):  
Cross Section ◽  
Fluorescent Dyes ◽  
Numerical Technique ◽  
Circular Cross Section ◽  
Fluorescent Dye ◽  
Double Layers ◽  
Wall Region ◽  
Velocity Data ◽  
Analysis Technique ◽  
Near Wall

A combined experimental and numerical analysis technique for velocity profiles in liquid microchannel flows is described. The working fluids employed are aqueous solutions with caged fluorescent dyes. A sheet of fluorescent dye is photo-injected by briefly exposing a cross-section of the fluid to ultraviolet light. The transport of the resulting ‘band’ of fluorescent dye is imaged onto a CCD camera using an epi-illumination fluorescent microscope system. The velocity profile is calculated from images acquired and processed after each uncaging event. The analysis technique utilizes several images, to provide velocity data with an increased signal-to-noise ratio. This combined experimental/numerical technique can provide velocity data in the near-wall region as well as in the bulk. Results are shown to compare favorably to analytical solutions in both pressure-driven and electroosmotic flow in circular cross-section capillaries of 205μm and 102μm inner diameters, respectively. Near-wall resolution is verified through application to electroosmotic flows with thin electrical double layers.

Heat-Transfer Analysis of Visco-Elastic Giesekus Fluid in a Duct Between Parallel Plates and in a Straight Pipe of a Circular Cross-Section

2015 ◽  
Author(s):  
Sara N. AlMelhi ◽  
Lyes Khezzar ◽  
Mohamed Alshehhi ◽  
Abdelkader Filali
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Numerical Solutions ◽  
Numerical Technique ◽  
Circular Cross Section ◽  
Heat Transfer Analysis ◽  
Rheological Parameters ◽  
Parallel Plates ◽  
Straight Pipe ◽  
Finite Element Software

This work aims to conduct numerical simulation to investigate the convective heat transfer of viscoelastic fluids obeying Giesekus model flowing either along straight pipe of circular cross-section or within the space between parallel plates with constant heat flux thermal boundary condition and neglected viscous dissipation. The numerical technique used is based on finite element software (ANSYS Polyflow 14.0) and the obtained numerical solutions are compared against the analytical solution available in literature. The effect of the rheological parameters on the heat transfer enhancement is discussed.

On the Proper Boundary Conditions for a Beam

1992 ◽  
Vol 59 (4) ◽  
pp. 915-922 ◽  
Author(s):  
H. Fan ◽  
G. E. O. Widera
Keyword(s):  
Asymptotic Expansion ◽  
Boundary Conditions ◽  
Cross Section ◽  
Boundary Data ◽  
Circular Cross Section ◽  
Numerical Calculations ◽  
Analysis Technique ◽  
Outer Expansion ◽  
Beam Theories

Employing the asymptotic expansion approach, the boundary conditions of a beam are reconsidered in the present paper. Gregory and Wan’s (1984) decay analysis technique is extended here to formulate the boundary conditions for the outer expansion. Among the various prescribed boundary data, most of the attention is focused on the displacement case because engineering beam theories employ incorrect conditions for these data. Numerical calculations are carried out for the displacement prescribed beam having a circular cross-section.

SAF file: It's really three dimensional file

2018 ◽  
Vol 14 (1) ◽  
pp. 1
Author(s):  
Prof. Dr. Jamal Aziz Mehdi
Keyword(s):  
Cross Section ◽  
Root Canal ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Circular Motion ◽  
Root Canal Treatment ◽  
Metal Core ◽  
Rotating Blade

The biological objectives of root canal treatment have not changed over the recentdecades, but the methods to attain these goals have been greatly modified. Theintroduction of NiTi rotary files represents a major leap in the development ofendodontic instruments, with a wide variety of sophisticated instruments presentlyavailable (1, 2).Whatever their modification or improvement, all of these instruments have onething in common: they consist of a metal core with some type of rotating blade thatmachines the canal with a circular motion using flutes to carry the dentin chips anddebris coronally. Consequently, all rotary NiTi files will machine the root canal to acylindrical bore with a circular cross-section if the clinician applies them in a strictboring manner

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