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Understanding the Piche evaporimeter as a simple integrating mass transfer meter

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Abstract

Results are presented of a comparison of measured and calculated evaporation rates of the Piche evaporimeter under indoor and outdoor (within a meteorological screen) conditions. In both cases, application of mass transfer formulae in use for horizontal (turbulent) flow to the evaporating blotting paper of the instrument yield very good results under pure forced convection conditions. For mixed convection regimes, comparisons using either pure free (combined heat and mass transfer) or pure forced convection equations give as expected too low calculated values. Reasons for such differences with measured values are reviewed. Our forced convection results confirm that main stream turbulence is only of influence on mass transfer to a zero incidence flow in combination with pressure gradient (bluff body) effects, which under our conditions appear to be absent around the Piche surfaces. The same results prove absence of any influence of the particular temperature distribution over the blotting paper on the mass transfer. The understanding and importance of these conclusions in relation to the use of the Piche evaporimeter as a simple integrating mass transfer meter under actual farming conditions are discussed. The importance to obtain such mass transfer data is explained in the introduction.

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Abbreviations

A :

Numerical constant in free convection Sherwood number

β :

Coefficient of thermal expansion (K−1)

C (s, b) :

Water vapour concentration average at the evaporating surface (s) and in the bulk air (b) (g m−3)

D :

Coefficient of molecular diffusion of water vapour in air (m2 s−1)

d :

Characteristic dimension of the paper disc in the direction of flow (m)

E (c, m) :

Evaporation rates of the Piche evaporimeter, calculated (c) and measured (m) (units in text)

e (s, b) :

Partial water vapour pressure average at the evaporating surface (s) and in the bulk air (b) (mbar)

Gr:

Grashof number

g :

Acceleration of gravity (m s−2)

m :

Number of measuring periods

n :

Numerical constant in free convection Sherwood number

ν :

Coefficient of kinematic viscosity of air (m2 s−1)

P :

Atmospheric pressure (mbar)

Re:

Reynolds number

ρ (s, b) :

Air density average at the evaporating surface (s) and of the bulk air (b) (g m−3)

Sh:

Sherwood number

T (s, b) :

Temperature average of the evaporating surface (s) and in the bulk air (b) (K)

T (vs, vb) :

Virtual temperature average at the evaporating surface (s) and in the bulk air (b) (K)

U :

Wind speed (air movement) average of the bulk air (m s−1)

References

  1. Stigter CJ and Kisamo EAC (1978) Univ Sc J (Dar es Salaam) 4: 53

    Google Scholar 

  2. Stigter CJ (1979) Q J Roy Met Soc 105: 1071

    Google Scholar 

  3. Thom AS and Oliver HR (1977) Q J Roy Met Soc 103: 345

    Google Scholar 

  4. Stigter CJ (1980) J Hydrol 45: 321

    Google Scholar 

  5. Doorenbos J and Pruitt WO (1977) Irrigation and drainage paper No. 24, FAO, Rome

  6. Slabbers PJ (1977) J Hydrol 34: 181

    Google Scholar 

  7. Stigter CJ (1974) Agric Res Rep 831, Pudoc, Wageningen

  8. Uiso CBS (1979) MSc Thesis, University of Dar es Salaam

  9. Uiso CBS and Stigter CJ (1980) Univ Sc J (Dar es Salaam) 6, in press

  10. Schlichting H (1968) Boundary-Layer Theory, McGraw-Hill Book Comp., New York, 6th ed.

    Google Scholar 

  11. Stewart DW and Lemon ER (1969) Technical Report ECOM 2–68

  12. Pearman GI, Weaver HL and Tanner CB (1972) Agric Meteorol 10: 83

    Google Scholar 

  13. Boothroyd RG (1973) Proceed First Austr Conf Heat and Mass Transf, Melbourne, Sect 3: 41

  14. Monteith JL (1973) Principles of environmental physics. Edward Arnold, London, 3rd ed.

    Google Scholar 

  15. Parkhurst DF, Duncan PR, Gates DM and Kreith F (1968) J Heat Transf (Trans ASME) 90: 71

    Google Scholar 

  16. Parlange J-Y, Waggoner PE and Heichel GH (1971) Plant Physiol 48: 437

    Google Scholar 

  17. De Vries DA and Venema HJ (1954) Vegetatio (Acta Geob) V-VI: 225

    Google Scholar 

  18. Goldstein RJ, Sparrow EM and Jones DC (1973) Int J Heat Mass Transf 16: 1025

    Google Scholar 

  19. Bandrowski J and Rybski W (1976) Int J Heat Mass Transf 19: 827

    Google Scholar 

  20. Bottemanne FA (1970) Mededelingen Landb Hogesch 70-11: 1

    Google Scholar 

  21. Monteith JL (1964) Proceed XIXth Symp Soc Exptl Biol, Swansea, p 205

  22. Parlange J-Y and Waggoner PE (1972) Plant Physiol 50: 60

    Google Scholar 

  23. Haseba T (1973) J Agric Meteorol (Tokyo) (in Japanese with English summary) 29: 25

    Google Scholar 

  24. Haseba T (1975) J Agric Meteorol (Tokyo) (in Japanese with English summary) 31: 135

    Google Scholar 

  25. Denmead OT and Bradley EF (1973) Proceed First Austr Conf Heat and Mass Transf, Melbourne, Sect 3: 13

  26. Denmead OT (1976) Chapter 1 in: Monteith JL (ed), Vegetation and the atmosphere, Vol 2, Academic Press, London, p 1

    Google Scholar 

  27. Kowalski GJ and Mitchell JW (1976) J Heat Transf (Trans ASME) 98: 649

    Google Scholar 

  28. Cowan IR (1972) Agric Meteorol 10: 311

    Google Scholar 

  29. Takechi O and Haseba T (1973) J Agric Meteorol (Tokyo) (in Japanese with English summary) 28: 213

    Google Scholar 

  30. Haseba T and Takechi O (1973) J Agric Meteorol (Tokyo) (in Japanese with English summary) 28: 149

    Google Scholar 

  31. Haseba T (1974) J Agric Meteorol (Tokyo) 30: 45

    Google Scholar 

  32. Fuchs M (1979) Chapter 14 in: Perry RA and Goodall DW (ed), Arid-land ecosystems: structure, functioning and management, Vol 1, Cambridge Univ Press, p 393

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Authors and Affiliations

  1. Section Agricultural Physics, Physics Department, University of Dar es Salaam, Dar es Salaam, Tanzania

    C. J. Stigter & C. B. S. Uiso

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  1. C. J. Stigter
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  2. C. B. S. Uiso
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Stigter, C.J., Uiso, C.B.S. Understanding the Piche evaporimeter as a simple integrating mass transfer meter. Appl. Sci. Res. 37, 213–223 (1981). https://doi.org/10.1007/BF00951248

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