Development of a Methodology for Adaptation of Refractive Index Under Controlling Kinematic Viscosity for PIV

Author(s):  
Shuya Shida ◽  
Hiroyuki Kosukegawa ◽  
Makoto Ohta

Blood vessel diseases such as ischemic cardiac disease or cerebral aneurysm are life-threatening disorders and as large a cause of death as cancer in many countries. The rupture of a cerebral aneurysm usually causes subarachnoidal hemorrhage the mortality of which is very high. Previous studies have proved that the genesis and growth of aneurysm are related to hemodynamics. Especially, in endovascular therapy for cerebral aneurysms using medical devices such as coils or stents, hemodynamics in an aneurysm are related to thrombosis formation in the aneurysm and to its repair. In vascular research using a biomodel (blood vessel phantom with mechanical properties similar to a human artery) for treating cerebral aneurysm, the working fluid, termed Blood-Mimicking Fluid (BMF), should mimic human blood with respect to viscosity so as to obtain realistic blood flow modeling in in vitro measurements. Moreover, refractive indices of BMF must be adjusted to fit biomodel materials because the materials used for Particle Image Velocimetry, one of the best tools for measurement of flow, have various refractive indices. For simultaneous adjustment of the two parameters, i.e. kinematic viscosity and refractive index, an aqueous mixture of glycerol and sodium iodide has been used in previous research. In this paper, we develop a systematic way to precisely find the two targeted parameters of BMF by showing the measurement values of the refractive index and the viscosity of the two aqueous solutions. The refractive index to light of fluorescent was measured with a critical angle refractometer while temperature of sample was also measured. And a vibration-type viscometer was used to obtain the dynamic viscosity under the same condition as refractive index measurement. These measurements were carried out at room temperature and pressure, respectively. As a result of detailed measurements at various proportions, refractive indices of the aqueous solution of glycerol (Gly. aq.) increase monotonically. On the one hand, the kinematic viscosity of Gly. aq. increases very slightly with its proportion and that of the aqueous solution of sodium iodide (NaI aq.) exhibits unique behavior. The results of combining Gly. aq. and NaI aq. indicate that the mixture has a wide range of kinematic viscosity, including the value of blood (around 3.8 mm2/s), at the targeted refractive index. In conclusion, this mixing method is useful for BMF preparation with the adjustment of refractive index and kinematic viscosity.

2019 ◽  
Vol 62 (4) ◽  
Author(s):  
Fardad Koohyar ◽  
Javad Nasiri ◽  
Farhoush Kiani

The glycerol, D-glucose monohydrate (DGMH), sucrose, and sodium chloride are used in food industries and the measurement of properties for these components and their aqueous solutions can be important. In this research work, the refractive indices for binary solutions of (methanol + glycerol), (ethanol + glycerol), ternary solutions of (water + glycerol + DGMH), (water + glycerol + sucrose), (water + sucrose + DGMH), (water + sucrose + ethanol), (water + ethanol + DGMH), (water + NaCl + DGMH), (water + methanol + NaCl), (water + ethanol + NaCl), (water + NaCl + glycerol), (water + sucrose + NaCl), and quaternary solutions of (water + ethanol + sucrose + DGMH), (water + ethanol + sucrose + glycerol), (water + NaCl + sucrose + glycerol) were measured in wide range of mole fractions at T = 293.15 K and atmospheric pressure. For binary solutions of this study, the changes of refractive index on mixing, ∆nD, were calculated in each mole fraction at T = 293.15 K. Also, the refractive index of binary solutions was fitted by a semi-empirical equation. The constant of this equation, Kr, was represented by Koohyar et al. in 2011. This constant can be used to investigate power of interactions between solute and solvent molecules. For ternary and quaternary solutions of this study, a semi-empirical equation was used to determine refractive indices at given temperature. The comparison between calculated and experimental refractive indices shows that there is a good agreement between them especially in lower molal concentrations.    


2014 ◽  
Vol 1051 ◽  
pp. 946-950 ◽  
Author(s):  
Jian Gang Wang ◽  
Hua Lin Wang ◽  
Yi Fan ◽  
Yuan Huang

In imaging measurements on the fluid flow, the quality of particle image is essential to the outcomes of the velocity field. The method to eliminate the problems of refraction and reflection is to match the refractive indices of the working fluid and the surrounding solid wall. In this article, a comprehensive summary of the refractive index matching method was presented. Three fluid materials, two organic and one non-organic was used to conduct index matching and their effect were compared. Results show the perfect index matching is effective to improve the measurement accuracy of imaging measurements.


2021 ◽  
Vol 255 ◽  
pp. 05002
Author(s):  
Carlos Damián Rodríguez-Fernánde ◽  
Elena López Lago ◽  
Christian Schröder ◽  
Luis M. Varela

In this contribution we simulate the refractive index of several ion combinations yielding ionic liquids. The results show that their structural tunability can be exploited to successfully design liquids with task-specific refractive indices over a wide range of values, even higher than 2.0. Some designing clues are provided, being charge delocalization and the presence of fluorine atoms key factors to reach ion combinations with the highest refractive index possible.


Author(s):  
Walter C. McCrone

An excellent chapter on this subject by V.D. Fréchette appeared in a book edited by L.L. Hench and R.W. Gould in 1971 (1). That chapter with the references cited there provides a very complete coverage of the subject. I will add a more complete coverage of an important polarized light microscope (PLM) technique developed more recently (2). Dispersion staining is based on refractive index and its variation with wavelength (dispersion of index). A particle of, say almandite, a garnet, has refractive indices of nF = 1.789 nm, nD = 1.780 nm and nC = 1.775 nm. A Cargille refractive index liquid having nD = 1.780 nm will have nF = 1.810 and nC = 1.768 nm. Almandite grains will disappear in that liquid when observed with a beam of 589 nm light (D-line), but it will have a lower refractive index than that liquid with 486 nm light (F-line), and a higher index than that liquid with 656 nm light (C-line).


1979 ◽  
Vol 44 (7) ◽  
pp. 2064-2078 ◽  
Author(s):  
Blahoslav Sedláček ◽  
Břetislav Verner ◽  
Miroslav Bárta ◽  
Karel Zimmermann

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.


2009 ◽  
Vol 17 (3) ◽  
Author(s):  
J. Saktioto ◽  
J. Ali ◽  
M. Fadhali

AbstractFiber coupler fabrication used for an optical waveguide requires lossless power for an optimal application. The previous research coupled fibers were successfully fabricated by injecting hydrogen flow at 1 bar and fused slightly by unstable torch flame in the range of 800–1350°C. Optical parameters may vary significantly over wide range physical properties. Coupling coefficient and refractive index are estimated from the experimental result of the coupling ratio distribution from 1% to 75%. The change of geometrical fiber affects the normalized frequency V even for single mode fibers. V is derived and some parametric variations are performed on the left and right hand side of the coupling region. A partial power is modelled and derived using V, normalized lateral phase constant u, and normalized lateral attenuation constant, w through the second kind of modified Bessel function of the l order, which obeys the normal mode and normalized propagation constant b. Total power is maintained constant in order to comply with the energy conservation law. The power is integrated through V, u, and w over the pulling length of 7500 µm for 1-D. The core radius of a fiber significantly affects V and power partially at coupling region rather than wavelength and refractive index of core and cladding. This model has power phenomena in transmission and reflection for an optical switch and tunable filter.


Author(s):  
Shang-Feng Yang ◽  
Je-Chin Han ◽  
Salam Azad ◽  
Ching-Pang Lee

This paper experimentally investigates the effect of rotation on heat transfer in typical turbine blade serpentine coolant passage with ribbed walls at low Mach numbers. To achieve the low Mach number (around 0.01) condition, pressurized Freon R-134a vapor is utilized as the working fluid. The flow in the first passage is radial outward, after the 180 deg tip turn the flow is radial inward to the second passage, and after the 180 deg hub turn the flow is radial outward to the third passage. The effects of rotation on the heat transfer coefficients were investigated at rotation numbers up to 0.6 and Reynolds numbers from 30,000 to 70,000. Heat transfer coefficients were measured using the thermocouples-copper-plate-heater regional average method. Heat transfer results are obtained over a wide range of Reynolds numbers and rotation numbers. An increase in heat transfer rates due to rotation is observed in radially outward passes; a reduction in heat transfer rate is observed in the radially inward pass. Regional heat transfer coefficients are correlated with Reynolds numbers for nonrotation and with rotation numbers for rotating condition, respectively. The results can be useful for understanding real rotor blade coolant passage heat transfer under low Mach number, medium–high Reynolds number, and high rotation number conditions.


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