Publication detail
Energy dissipation of the liquid in systems with a hydrophobic surface
FIALOVÁ, S. POCHYLÝ, F. HUDEC, M.
English title
Energy dissipation of the liquid in systems with a hydrophobic surface
Type
conference paper
Language
en
Original abstract
The work is divided into theoretical and experimental parts. In the theoretical part the viscous forces performance for both laminar as well as turbulent flow of compressible fluids are defined. It is split into the viscous forces useful power and the power corresponding to mechanical losses. This part is expressed by the dissipation function. It is shown that the dissipation function considering hydrophobic surfaces cannot be determined from the pressure difference. It is necessary to take into account the slip of the liquid over the hydrophobic surface which depends on the value of surface energy. The values of surface energy for different types of hydrophobic surfaces, obtained by experiment, are shown within this work. The new definition of the dissipation function for hydrophobic surfaces is presented depending on the adhesion coefficient, also determined by an experiment. The theoretical part of the work is complemented by experiment. The experiment is aimed at the differential pressure measurement in a circular cross section pipe. The results are processed for both laminar and turbulent stationary flow in relation to the flow. Both hydrophilic and hydrophobic surfaces and their mutual correlation are taken into consideration. On the basis of the new mathematical model for hydrophobic surfaces the value of dissipation function is determined depending on the slip velocity of the liquid along the hydrophobic surface.
English abstract
The work is divided into theoretical and experimental parts. In the theoretical part the viscous forces performance for both laminar as well as turbulent flow of compressible fluids are defined. It is split into the viscous forces useful power and the power corresponding to mechanical losses. This part is expressed by the dissipation function. It is shown that the dissipation function considering hydrophobic surfaces cannot be determined from the pressure difference. It is necessary to take into account the slip of the liquid over the hydrophobic surface which depends on the value of surface energy. The values of surface energy for different types of hydrophobic surfaces, obtained by experiment, are shown within this work. The new definition of the dissipation function for hydrophobic surfaces is presented depending on the adhesion coefficient, also determined by an experiment. The theoretical part of the work is complemented by experiment. The experiment is aimed at the differential pressure measurement in a circular cross section pipe. The results are processed for both laminar and turbulent stationary flow in relation to the flow. Both hydrophilic and hydrophobic surfaces and their mutual correlation are taken into consideration. On the basis of the new mathematical model for hydrophobic surfaces the value of dissipation function is determined depending on the slip velocity of the liquid along the hydrophobic surface.
Keywords in English
hydrophobic surface, liquid, flow
Released
12.05.2017
ISSN
2100-014X
Book
EFM16 – Experimental Fluid Mechanics 2016
Volume
143
Pages from–to
1–6
Pages count
6
BIBTEX
@inproceedings{BUT170605,
author="Simona {Fialová} and Edita {Mariánková} and František {Pochylý} and Martin {Hudec},
title="Energy dissipation of the liquid in systems with a hydrophobic surface",
booktitle="EFM16 – Experimental Fluid Mechanics 2016",
year="2017",
volume="143",
month="May",
pages="1--6",
issn="2100-014X"
}