The flow of liquids with a temperature anomaly of viscosity

2003 ◽  
Vol 3 ◽  
pp. 232-245
Author(s):  
V.N. Kireev ◽  
S.F. Urmancheev
Keyword(s):  
Fluid Flow ◽  
Temperature Dependence ◽  
Temperature Anomaly ◽  
Numerical Study ◽  
Liquid Sulfur ◽  
Temperature Range ◽  
External Conditions ◽  
Increasing Temperature ◽  
Viscosity Dependence

For the vast majority of liquids, viscosity is a function that decreases monotonically with increasing temperature. However, a number of substances in which processes of polymerization and depolymerization can occur in a certain temperature range have a viscosity with a nonmonotonic temperature dependence. This dependence, for example, is characteristic of liquid sulfur. In this paper we present the results of a numerical study of the features of the flow of a liquid with a certain model nonmonotonic viscosity dependence on the temperature. The formation of a ”viscous barrier“ that determines the nature of the fluid flow in the channel is established. The main regularities of the flow are determined depending on the parameters of the viscous anomaly and external conditions.

Numerical study on the fluid flow pass a square cylinder: The temperature-viscosity dependence

2014 ◽  
Vol 25 (03) ◽  
pp. 1350101
Author(s):  
Jianhua Lu ◽  
Sheng Li ◽  
Zhaoli Guo ◽  
Baochang Shi
Keyword(s):  
Fluid Flow ◽  
Free Stream ◽  
Numerical Study ◽  
Effect Of Temperature ◽  
Square Cylinder ◽  
Efficient Tool ◽  
Multiple Relaxation Time ◽  
Upward Velocity ◽  
Drag And Lift ◽  
Viscosity Dependence

In this paper, the 2D fluid flow pass a heated/cooled square cylinder exposed to a constant free-stream upward velocity is simulated via a multiple relaxation time (MRT) lattice-Boltzmann (LB) method. The buoyancy effect on the drag and lift coefficients as well as Nusselt number related is compared with the results in the existing literatures to validate the code used. The effect of temperature-viscosity dependence is then investigated to test whether the effect can be neglected or not for the mixed convection case. It is shown that the effect cannot be ignored when |Ri| > 0.15. Fortunately, the effect can be captured by using an effective temperature formula [J. M. Shi, D. Ferlach, M. Breuer, G. Biswas and F. Durst, Phys. Fluids16, 4331 (2004)] in a rather large range of Ri. All the numerical results, from another angle, also demonstrate that the MRT method is an efficient tool in simulating the problems such as the present one.

g-Values for γ-irradiated water as a function of temperature

1990 ◽  
Vol 68 (5) ◽  
pp. 712-719 ◽  
Author(s):  
A. John Elliot ◽  
Monique P. Chenier ◽  
Denis C. Ouellette
Keyword(s):  
Experimental Data ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Temperature Dependence ◽  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Hydrated Electron ◽  
Temperature Range ◽  
Increasing Temperature

The g-values of primary species formed in the γ-radiolysis of water have been estimated for the temperature range 25–300 °C. The g-values for the hydrated electron, the hydroxyl radical, and molecular hydrogen all increase approximately 50% over this temperature range. The g-values for the minor products, hydrogen peroxide and atomic hydrogen, probably also increase with temperature; however, there is evidence from some of the experimental data which suggests that these g-values may slightly decrease with increasing temperature. Keywords: radiolysis, g-values, temperature dependence.

Temperature dependence of the shape of the cellodextrins in aqueous solution

1967 ◽  
Vol 45 (20) ◽  
pp. 2363-2367 ◽  
Author(s):  
M. Ihnat ◽  
D. A. I. Goring
Keyword(s):  
Aqueous Solution ◽  
Temperature Dependence ◽  
Computational Methods ◽  
Negative Temperature ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Increasing Temperature

Intrinsic viscosities of the cellodextrins, cellobiose to cellohexaose, were measured in aqueous solution at temperatures from 25 to 70 °C. Axial ratios were determined using the Einstein–Simha viscosity relation and the computational methods developed previously. The results showed that the oligomers are fully extended over this temperature range and that the negative temperature coefficients of the intrinsic viscosities are caused by the dehydration of the molecules with increasing temperature.

scholarly journals WETTING ANGLE POLYTERMES FOR LEAD-SODIUM MELTS ON REFRACTORY METALS

2020 ◽  
pp. 113-119
Author(s):  
Барасби Сулейманович Карамурзов ◽  
Руслан Азаевич Кутуев ◽  
Мурат Хажисмелович Понежев ◽  
Виктор Адыгеевич Созаев ◽  
Астемир Хусенович Шерметов ◽  
...  
Keyword(s):  
Contact Angle ◽  
Stainless Steel ◽  
Temperature Dependence ◽  
Refractory Metals ◽  
Wetting Angle ◽  
Temperature Range ◽  
Drop Method ◽  
Pure Helium ◽  
Increasing Temperature

Методом лежащей капли изучена температурная зависимость краевого угла смачивания сплавов Pb - Na разной концентрации на подложках из Co - Cr, Ni - Cr, нержавеющей стали 251892. Измерения проводились методом лежащей капли в широком интервале температур от 359°С до 800 °С в атмосфере чистого марки А. Показано, что значение угла смачивания уменьшается с увеличением температуры, наблюдаются пороги смачивания. The temperature dependence of the contact angle for Pb - Na melts of different concentrations on Co - Cr , Ni - Cr and stainless steel 25X18H9C2 substrate was studied by the method of a lying drop. Measurements were carried out by a lying drop method in the temperature range from 359 to 800 °C in an atmosphere of pure helium grade A. It is shown that the value of the wetting angle decreases with increasing temperature, wetting thresholds are observed.

Temperature dependence of the electron resonance spectrum of the hydrazine positive ion

1968 ◽  
Vol 46 (10) ◽  
pp. 1703-1706 ◽  
Author(s):  
H. R. Falle
Keyword(s):  
Temperature Dependence ◽  
Torsional Vibration ◽  
Hyperfine Splitting ◽  
Resonance Spectrum ◽  
Electron Resonance ◽  
Temperature Study ◽  
Temperature Range ◽  
Increasing Temperature ◽  
Positive Ion

A temperature study of the hydrazine positive ion, N2H4+, showed that the ratio of the nitrogen hyperfine splitting to the proton hyperfine splitting, |aN/aH| increased with increasing temperature. The increase in |aN/aH| was approximately 3%, while the increase in aN itself was less than 1% over the 50 °C temperature range. This effect is attributed to torsional vibration about the N—N bond and is assessed on this basis.

A Parametric Numerical Study of Fluid Flow and Heat Transfer in a Computer Chassis

2015 ◽  
Vol 9 (3) ◽  
pp. 242 ◽  
Author(s):  
Efstathios Kaloudis ◽  
Dimitris Siachos ◽  
Konstantinos Stefanos Nikas
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Study ◽  
Flow And Heat Transfer

Specific features of the temperature dependence of tryptophan fluorescence lifetime in the temperature range of −170–20 °C

2020 ◽  
Vol 393 ◽  
pp. 112435
Author(s):  
Peter P. Knox ◽  
Vladimir V. Gorokhov ◽  
Boris N. Korvatovsky ◽  
Nadezhda P. Grishanova ◽  
Sergey N. Goryachev ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Fluorescence Lifetime ◽  
Tryptophan Fluorescence ◽  
Temperature Range
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