scholarly journals An experimental study of the evaporation rate of nanofluid droplets with SiO2 nanoparticles

2020 ◽  
Vol 1675 ◽  
pp. 012046
Author(s):  
E M Bochkareva ◽  
N B Miskiv ◽  
A D Nazarov ◽  
V V Terekhov ◽  
V I Terekhov
2021 ◽  
Vol 2119 (1) ◽  
pp. 012077
Author(s):  
A V Kokorin ◽  
A D Nazarov ◽  
A F Serov

Abstract This paper presents the results of an experimental study of the dynamics of evaporation of nanofluid droplets based on distilled water with a mass concentration of SiO2 nanoparticles of 0.1%, 0.5%, and 7% lying on a metal surface. The drop height was changed over time using original equipment, which is based on an integrated approach to the combined use of capacitive and optical recording methods. The experimental results show that the change in the height of nanofluid droplets with concentrations of 0.1%, 0.5%, and 7% is linear over the main part of the evaporation time interval. A deviation from the linear law is observed at the final stage, at the time interval of complete evaporation. The time for complete evaporation of droplets of nanofluids with a concentration of 0.1% increases by 20%, for droplets with a concentration of 0.5%, it increased by 28% in comparison with the evaporation of droplets of the base liquid. The particle concentration of 7% does not lead to an increase in the evaporation time of droplets in comparison with the evaporation of low concentration droplets. Before the formation of a jelly-like residue of nanoparticles, the evaporation rate of droplets with a particle concentration of 7% is comparable to the evaporation rate of droplets with a concentration of 0.1%.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Petr Sedlak ◽  
Adam Gajdos ◽  
Robert Macku ◽  
Jiri Majzner ◽  
Vladimir Holcman ◽  
...  

AbstractThe experimental study deals with the investigation of the effect of diverse crystallinity of imidazolium ionic-liquid-based SPE on conductivity and current fluctuations. The experimental study was carried out on samples consisting of [EMIM][TFSI] as ionic liquid, PVDF as a polymer matrix and NMP as a solvent. After the deposition, the particular sample was kept at an appropriate temperature for a specific time in order to achieve different crystalline forms of the polymer in the solvent, since the solvent evaporation rate controls crystallization. The ac/dc conductivities of SPEs were investigated across a range of temperatures using broadband dielectric spectroscopy in terms of electrical conductivity. In SPE samples of the higher solvent evaporation rate, the real parts of conductivity spectra exhibit a sharper transition during sample cooling and an increase of overall conductivity, which is implied by a growing fraction of the amorphous phase in the polymer matrix in which the ionic liquid is immobilized. The conductivity master curves illustrate that the changing of SPEs morphology is reflected in the low frequency regions governed by the electrode polarization effect. The dc conductivity of SPEs exhibits Vogel–Fulcher–Tammann temperature dependence and increases with the intensity of thermal treatment. Spectral densities of current fluctuations showed that flicker noise, thermal noise and shot noise seems to be major noise sources in all samples. The increase of electrolyte conductivity causes a decrease in bulk resistance and partially a decrease in charge transfer resistance, while also resulting in an increase in shot noise. However, the change of electrode material results in a more significant change of spectral density of current fluctuations than the modification of the preparation condition of the solid polymer electrolyte. Thus, the contact noise is considered to contribute to overall current fluctuations across the samples.


Author(s):  
В.А. Архипов ◽  
С.А. Басалаев ◽  
Н.Н. Золоторёв ◽  
К.Г. Перфильева ◽  
А.С. Усанина

New method for determining the evaporation rate of single levitating drop at radiant heat flux has been proposed. The results of experimental study of the evaporation rate of distilled water drop upon heating by radiant and convective heat flux in the range of q = (0.25–1.5) W/cm^2 are presented. Comparative analysis of the features of the drop evaporation during radiant and convective heating has been carried out.


2020 ◽  
Vol 90 (1) ◽  
pp. 33
Author(s):  
А.В. Минаков ◽  
А.С. Лобасов ◽  
М.И. Пряжников ◽  
Л.С. Тарасова ◽  
Н.Я. Василенко ◽  
...  

Evaporation of nanofluids based on distilled water and the silicium and zirconium dioxides, aluminium oxide as well as the diamond has been experimentally studied. The average diameter of the SiO2 nanoparticles was 25 nm, of the ZrO2 nanoparticles was 105 nm, of the Al2O3 nanoparticles was 43 nm and of the diamond nanoparticles was 5 nm. The synchronous thermoanalyser STA 449 С Jupiter was used in the investigation of the evaporation processes. The dependences of the evaporation rate on the volume concentration of the nanoparticles were obtained as a result of the experimental studies. It was shown that as the nanoparticles volume concentration increases the nanofluids evaporation rates monotonically increase too.


Author(s):  
Jyoti Prakash ◽  
Basant Singh Sikarwar

The evaporation of sessile drop has a wide range of application that includes printing, washing, cooling, and coating. Due to the complex nature of drop evaporation process, this phenomenon is reliant on several parameters such as ambiance and physiochemical properties of liquid and surface. In the present study, a mathematical model of water droplet evaporation on an engineered aluminum surface is developed. Experimental study is carried out for the validation of code. The data obtained from the simulation is validated against the data obtained from an experimental study as well as the data available in the literature and good agreement was found among them. Post-validation, the effect of surface wettability and environment conditions on a droplet evaporation rate is estimated. It is inferred from the outcomes that the temperature at the apex of the drop varies linearly with the increasing relative humidity. Droplet volume has a significant impact on the evaporation rate and comparatively higher evaporative flux for a smaller volume of the drop with large contact angles. This unveils the possibility of achieving the required evaporation rate by controlling surface wettability and relative humidity conditions near the drop.


Sign in / Sign up

Export Citation Format

Share Document