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Local film thickness and temperature distribution measurement in wavy liquid films with a laser-induced luminescence technique

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Abstract

Heat transfer in falling liquid film systems is enhanced by waviness. Comprehension of the underlying kinetic phenomena requires experimental data of the temperature field with high spatiotemporal resolution. Therefore a non-invasive measuring method based on luminescence indicators is developed. It is used to determine the temperature distribution and the local film thickness simultaneously. Results are presented for the temperature distribution measurement in a laminar-wavy water film with a liquid side Reynolds number of 126 flowing down a heated plane with an inclination angle of 2° at two positions in flow direction. The measured temperature distributions are used to calculate the local heat transfer coefficient for solitary waves at two positions in flow direction.

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Abbreviations

c :

Phase velocity, m/s

C :

Molar concentration, mol/m3

d :

Thickness, diameter, m

f :

Frequency, 1/s

F :

Objective functional

H :

Height of channel, m

I :

Intensity, W/m2

K :

Constant device factor, V m/W

L :

Length of channel, m

M :

Measured signal, V

n :

Distribution of effective emission area, m2

N :

Number of nodal points

Pr :

Prandtl number = ν/κ

Re :

Reynolds number \({=\dot{V}/(\nu\ W)}\)

t :

Time, s

u :

Streamwise velocity, m/s

v :

Transversal velocity, m/s

V :

Volume, m3

W :

Width of channel, m

x :

Streamwise coordinate, m

y :

Normal coordinate, m

α:

heat transfer coefficient, W/(m2 K)

η:

dynamic viscosity, kg/(m s)

φ:

regularization parameter

ϕ:

inclination angle, °

κ:

thermal diffusivity, m2/s

λ:

thermal conductivity, W/(m K)

λ:

wave length, m

ν:

kinematic viscosity, m2/s

ϑ:

temperature, °C

ρ:

density, kg/m3

τ:

decay constant, s

d:

disturbance

exp:

experimental

f:

film

g:

gas

i:

interface

l:

liquid, lower bound

m:

mean

max:

maximum value

Nu:

Nusselt

ob:

observation volume

P:

phosphorescence

s:

substrate

sta:

stagnant liquid

u:

upper bound

w:

wave peak, wall

*:

scaled value

\({\Vert \cdot \Vert^2_2}\) :

squared euclidian norm

References

  • Adomeit P, Leefken A, Renz U (2000) Experimental and numerical investigations on wavy films. In: Proceedings of the 3rd European thermal science conference, vol 2, pp 1003–1009

  • Alekseenko SV, Nakoryakov VE, Pokusaev PG (1994) Wave flow of liquid films. Begell House, New York

    Google Scholar 

  • Alhusseini K, Tuzla M, Chen JC (1998) Falling film evaporation of single component liquids. Int J Heat Mass Transf 41:1623–1632

    Article  Google Scholar 

  • Almgren M (1968) The natrual phosphorescence lifetime of biacetyl and benzil in fluid solution. Photochem Photobiol 6:829–840

    Google Scholar 

  • Al-Sibai F (2005) Local and instantaneous distribution of heat transfer rates and velocities in thin wavy films. PhD Thesis, RWTH Aachen, Aachen

  • Al-Sibai F, Leefken A, Renz U (2002) Local and instantaneous distribution of heat transfer rates and velocities in thin wavy films. In: Proceedings of Eurotherm 71 on visualization, imaging and data analysis in convective heat and mass transfer, Reims, France, pp 28–30

  • Bäckström HLJ, Sandros K (1958) The quenching of the long-lived fluorescence of biacetyl in solutions. Acta Chem Scand 12:823–832

    Article  Google Scholar 

  • Brauer H (1961) Grundlagen der Einphasen- und Mehrphasenströmungen, Verlag Sauerländer, Aarau und Frankfurt am Main, pp 673

  • Brauner N, Maron DM (1982) Characteristics of inclined thin films, waviness and the associated mass transfer. Int J Heat Mass Transf 25(1):99–110

    Article  Google Scholar 

  • Conlisk AT (1995) Analytical solutions for the heat and mass transfer in a falling film absorber. Chem Eng Sci 50(4):651–660

    Article  Google Scholar 

  • Dietze G (2005) Modellierung des Impuls-, Wärme- und Stofftransportes in laminar-welligen Rieselfimen unter Verwendung effectiver Transportkoeffizienten, MS Thesis, RWTH Aachen, Germany

  • Günther A, Rudolf von Rohr P (2000) Simultaneous visualization of temperature and velocity fields in turbulent natural convection. In: Proceedings of the 34th National Heat Transfer conference, Pittsburgh

  • Günther A, Rudolf von Rohr P (2002) Influence of the optical configuration on temperature measurements with fluid-dispersed TLCs. Exp Fluids 32:533–541

    Article  Google Scholar 

  • Hansen C (1998) Rank-deficient and ill-posed problems: numerical aspects of LSIAM inversion. SIAM monograph, Philadelphia, USA

  • Hishida K, Sakakibara J (2000) Combined planar laser-induced fluorescence-particle image velocimetry technique for velocity and temperature fields. Exp Fluids 29:129–141

    Article  Google Scholar 

  • Killion JD, Garimella S (2001) A critical review of models of coupled heat and mass transfer in falling-film absorption. Int J Refrig 24:755–797

    Article  Google Scholar 

  • Lel VV, Leefken A, Al-Sibai F, Renz U (2004) Extension of the chromatic confocal imaging method for local thickness measurements of wavy films. In: Proceedings of 5th international conference on multiphase flow, ICMF’04, Yokohama, Japan, May 30–June 4 2004, vol 20, paper no. 155

  • Lide DR (Editor-in-Chief) (2000) CRC handbook of chemistry and physics, 80th edn. CRC Press LLC, Boca Raton

  • Miladinova S, Slavtchev S, Lebon G, Legros JC (2002) Long-wave instabilities of non-uniformly heated falling films. J Fluid Mech 453:153–175

    Article  MATH  MathSciNet  Google Scholar 

  • Miyara A (1999) Numerical analysis on flow dynamics and heat transfer of falling liquid films with interfacial waves. Heat Mass Transf 35:298–306

    Article  Google Scholar 

  • Nusselt W (1916) Die Oberflächenkondensation des Wasserdampfes. Z VDI 60:514–546

    Google Scholar 

  • Ramaswamy B, Chippada S, Joo SW (1996) A full-scale numerical study of interfacial instabilities in thin-film flow. J Fluid Mech 325:163–194

    Article  MATH  Google Scholar 

  • Roberts RM, Chang HC (2000) Wave-enhanced interfacial transfer. Chem Eng Sci 55:1127–1141

    Article  Google Scholar 

  • Sakakibara J, Adrian RJ (1999) Whole field measurement of temperature in water using two-color laser induced fluorescence. Exp Fluids 26:7–15

    Article  Google Scholar 

  • Schagen A, Modigell M (2005) Luminescence technique for the measurement of local concentration distribution in thin liquid films. Exp Fluids 38:174–184

    Article  Google Scholar 

  • Tikhonov AN, Arsenin VY (1977) Solutions of ill-posed problems. V.H. Winston and Sons. 1511 K Street, N.W., Washington, D.C. 20005

  • Wasden FK, Dukler AE (1990) A numerical study of mass transfer in free falling films. AIChE J 36:1379–1390

    Article  Google Scholar 

  • Wolfersdorf L (1994) Inverse und schlecht gestellte Probleme—Eine Einführung, Sitzungsberichte der sächsischen Akademie der Wissenschaften zu Leipzig, 124(5)

Download references

Acknowledgments

The authors gratefully acknowledge the financial support of the Deutsche Forschungsgemeinschaft (DFG) within the Collaborative Research Center (SFB) 540 “Model-based Experimental Analysis of Kinetic Phenomena in Fluid Multi-phase Reactive Systems”.

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Schagen, A., Modigell, M. Local film thickness and temperature distribution measurement in wavy liquid films with a laser-induced luminescence technique. Exp Fluids 43, 209–221 (2007). https://doi.org/10.1007/s00348-007-0289-z

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