Detail publikace

Energy dissipation of the liquid in systems with a hydrophobic surface

FIALOVÁ, S. POCHYLÝ, F. HUDEC, M.

Anglický název

Energy dissipation of the liquid in systems with a hydrophobic surface

Typ

článek ve sborníku ve WoS nebo Scopus

Jazyk

en

Originální abstrakt

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.

Anglický abstrakt

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.

Klíčová slova anglicky

hydrophobic surface, liquid, flow

Vydáno

12.05.2017

ISSN

2100-014X

Kniha

EFM16 – Experimental Fluid Mechanics 2016

Ročník

143

Strany od–do

1–6

Počet stran

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"
}