VISCOSITY EFFECTS IN A CHANNEL OF SMALL EXPONENTIAL DIVERGENCE

1935 ◽  
Vol 12 (5) ◽  
pp. 676-685 ◽  
Author(s):  
G. N. Patterson
Keyword(s):  
Experimental Investigation ◽  
Flow Characteristics ◽  
Theoretical Treatment ◽  
Photographic Method ◽  
General Flow ◽  
Viscosity Effects ◽  
Diverging Channel ◽  
Theoretical Considerations ◽  
Theoretical Results ◽  
Good Agreement

An experimental investigation of a flow form, deduced by Blasius from theoretical considerations, was carried out with air as the medium. A photographic method of measuring velocity distributions was adopted, and a diverging channel was designed from considerations based on the theoretical treatment and on requirements arising out of the experimental method. At a Reynolds number of 35, curves of velocity distribution were measured at various positions along the channel, and comparisons were then made with the corresponding theoretical curves. Good agreement was found over the region of the channel to which the theoretical results could be applied. A study of the experimental curves in that part of the channel to which the theoretical results could not be applied quantitatively showed further that the general flow characteristics described by Blasius are to be found in this region.

An Experimental Investigation of Gaseous Flow Characteristics in Microchannels

2004 ◽  
Author(s):  
G. H. Tang ◽  
Y. L. He
Keyword(s):  
Experimental Investigation ◽  
Flow Characteristics ◽  
Fused Silica ◽  
Helium Flow ◽  
Gaseous Flow ◽  
Compressibility Effect ◽  
Circular Tubes ◽  
Flow Friction ◽  
Friction Factors ◽  
Good Agreement

Gaseous flow characteristics in fused silica microtubes and square microchannels are studied experimentally. The existing works in the literature on experimental gaseous flow are analyzed. The data in fused silica micro circular tubes with diameters ranging from 50 μm to 201 μm and the data in fused silica micro square channels with hydraulic diameter ranging from 52 μm to 100 μm show that the flow friction factors are in good agreement with the theoretical prediction for conventional tubes and no distinguishable deviation is observed. The transition Reynolds number is around 2000 and a slight early transition from laminar to turbulent is observed due to the compressibility effect. For the helium flow in fused silica microtubes with inner diameters ranging from 10 μm to 20 μm, the decrease in friction factor is observed. In addition, factors including roughness, compressibility and rarefaction that may have significant effects on flow characteristics in microchannels are discussed.

Soret Measurement for Multi-Component Hydrocarbon Mixtures from Space Experiment Conducted Onboard FOTON M3 Unmanned Satellite

2012 ◽  
Vol 225 ◽  
pp. 470-474 ◽  
Author(s):  
M. Ziad Saghir ◽  
Seshasai Srinivasan ◽  
Stefan Van Vaerenbergh
Keyword(s):  
Experimental Investigation ◽  
Space Experiment ◽  
Experimental Investigations ◽  
Hydrocarbon Mixture ◽  
Hydrocarbon Mixtures ◽  
Component System ◽  
Thermodiffusion Coefficient ◽  
Free Environment ◽  
Theoretical Results ◽  
Good Agreement

In an unprecedented experimental investigation, a binary, a ternary and a four-component hydrocarbon mixture at different pressure have been studied in a nearly convection free environment to understand the thermodiffusion process. Experimental investigations of the mixtures have been conducted in space onboard the spacecraft FOTON-M3. The experiment objective was to measure the thermodiffusion coefficient for multi-component hydrocarbon mixtures. Then the experimental results have also been used to test a thermodiffusion model that has been calibrated based on the results of previous experimental investigations. Results showed a good agreement with current theoretical results except for the four-component system where discrepancies were found and discussed.

CHARACTERISTICS OF A TOROIDAL RESONATOR FOR PLASMA DIAGNOSTICS

1967 ◽  
Vol 45 (12) ◽  
pp. 3979-3989 ◽  
Author(s):  
M. Šícha ◽  
G. G. Cloutier ◽  
R. Bolton
Keyword(s):  
Electrical Conductivity ◽  
Experimental Investigation ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Resonant Frequency ◽  
Plasma Diagnostics ◽  
Field Configuration ◽  
Dielectric Sphere ◽  
Theoretical Results ◽  
Good Agreement

In this paper an experimental investigation of the electric-field configuration in a toroidal resonator has been carried out by measuring the shift of the resonant frequency when a small dielectric sphere is introduced in the resonator. The good agreement between the experimental and the theoretical results shows that the assumptions concerning the electromagnetic-field configuration are correct and the method can be used in measuring the electrical conductivity of a plasma.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

Experimental investigation and modelling of light scattering in a-Si:H solar cells deposited on glass/ZnO:Al substrates

2002 ◽  
Vol 715 ◽  
Author(s):  
J. Krc ◽  
M. Zeman ◽  
O. Kluth ◽  
F. Smole ◽  
M. Topic
Keyword(s):  
Surface Roughness ◽  
Experimental Investigation ◽  
Solar Cells ◽  
Angular Distribution ◽  
Light Scattering ◽  
Optical Model ◽  
Distribution Functions ◽  
Interface Roughness ◽  
Scattering Parameters ◽  
Good Agreement

AbstractThe descriptive scattering parameters, haze and angular distribution functions of textured ZnO:Al transparent conductive oxides with different surface roughness are measured. An approach to determine the scattering parameters of all internal interfaces in p-i-n a-Si:H solar cells deposited on the glass/ZnO:Al substrates is presented. Using the determined scattering parameters as the input parameters of the optical model, a good agreement between the measured and simulated quantum efficiencies of the p-i-n a-Si:H solar cells with different interface roughness is achieved.

Studies of local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) crystals

2021 ◽  
Vol 76 (4) ◽  
pp. 299-304
Author(s):  
Fu Chen ◽  
Jian-Rong Yang ◽  
Zi-Fa Zhou
Keyword(s):  
Crystal Field ◽  
Elongation Ratio ◽  
Paramagnetic Resonance ◽  
Local Structures ◽  
Epr Parameters ◽  
Structure Constants ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic ◽  
Theoretical Results ◽  
Good Agreement

Abstract The electron paramagnetic resonance (EPR) parameters (g factor g i , and hyperfine structure constants A i , with i = x, y, z) and local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) are theoretically investigated using the high order perturbation formulas of these EPR parameters for a 3d 9 ion under orthorhombically elongated octahedra. In the calculations, contribution to these EPR parameters due to the admixture of d-orbitals in the ground state wave function of the Cu2+ ion are taken into account based on the cluster approach, and the required crystal-field parameters are estimated from the superposition model which enables correlation of the crystal-field parameters and hence the studied EPR parameters with the local structures of the Cu2+ centers. Based on the calculations, the Cu–H2O bonds are found to suffer the axial elongation ratio δ of about 3 and 2.9% along the z-axis, meanwhile, the planar bond lengths may experience variation ratio τ (≈3.8 and 1%) along x- and y-axis for Cu2+ center in (NH4)2Zn(SO4)2·6H2O and Rb2Zn(SO4)2·6H2O, respectively. The theoretical results show good agreement with the observed values.

On the Flow Fields of Inertial Impactors

1974 ◽  
Vol 96 (4) ◽  
pp. 394-400 ◽  
Author(s):  
V. A. Marple ◽  
B. Y. H. Liu ◽  
K. T. Whitby
Keyword(s):  
Flow Field ◽  
Stokes Equations ◽  
Relaxation Method ◽  
Water Model ◽  
Navier Stokes ◽  
Visualization Technique ◽  
Navier Stokes Equations ◽  
Theoretical Results ◽  
Plate Distance ◽  
Good Agreement

The flow field in an inertial impactor was studied experimentally with a water model by means of a flow visualization technique. The influence of such parameters as Reynolds number and jet-to-plate distance on the flow field was determined. The Navier-Stokes equations describing the laminar flow field in the impactor were solved numerically by means of a finite difference relaxation method. The theoretical results were found to be in good agreement with the empirical observations made with the water model.

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