Aerosol Formation in a Mixing Layer

  • S. V. Sherikar
  • R. Chevray

Abstract

Flow visualization has for long been a powerful tool in experimental studies in fluid mechanics. Here, a novel technique utilizing the NH3-HC1 reaction is described. The product of this reaction appears as a white and dense aerosol which can readily be photographed. Since the reaction itself is fast, information is also provided on local entrainment and mixing. This technique has been applied to advantage to the study of coherent structures in a plane mixing layer the results of which are presented here.

Keywords

Vortex Quartz Coherence Eter Settling 

Nomenclature

F(d)

total number of particles per unit volume larger than a given number d

H

shape factor for boundary layer (δDM)

N

total number of particles per unit volume

U

mean flow velocity

d

particle diameter

k

rate constant for NH3 -HC1 reaction [1.9 x 10-17 cm3/s (at STP)]

knucl

rate constant for nucleation of particulate NH4C1 (2 x 10-229 cm48/s at STP)

kcond

rate constant for condensation of colloidal NH4Cl

m

arbitrary number

q

a constant

t

time

α

constant = (13 ± 3) x 104 cm-1

[NH3 ]

concentration of NH3

[HC1]

concentration of HC1

δD

displacement thickness

δM

momentum thickness

Subscripts

(g)

refers to gaseous phase

(s)

refers to solid phase

1

refers to fast stream

2

refers to slow stream

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References

  1. 1.
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  2. 2.
    Brown, G.L., Roshko, A.: On density effects and large structures in turbulent mixing layers. J. Fluid Mech. 64, 775 (1974)ADSCrossRefGoogle Scholar
  3. 3.
    Dimotakis, P.E., Brown, G.L.: The mixing layer at high Reynolds number: Large structure dynamics and entrainment. J. Fluid Mech. 78, 535–560 (1976)ADSCrossRefGoogle Scholar
  4. 4.
    Roshko, A.: “The Plane mixing Layer: Flow Visualization Results and Three Dimensional Effects”, Proceedings, International Conference on the Role of Coherent Structures in Modelling Turbulence and Mixing, Madrid, Spain, 1980Google Scholar
  5. 5.
    Wygnanski, I., Oster, D., Fiedler, H.: “The Forced, Plane, Turbulent Mixing-Layer: A Challenge for the Predictor, Proceedings, Second Symposium on Turbulent Shear Flows, Imperial College, London, 1979Google Scholar
  6. 6.
    Heicklen, J.: Colloid Formation and Growth (Academic Press, New York 1976)Google Scholar
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    Countess, R.J., Heicklen, J.: Kinetics of particle growth. II. Kinetics of the reaction of ammonia and hydrogen chloride and the growth of particulate ammonium chloride. J. Phys. Chem. 77(4), 444–447 (1973)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1982

Authors and Affiliations

  • S. V. Sherikar
    • 1
  • R. Chevray
    • 1
  1. 1.Department of Mechanical EngineeringState University of New York at Stony BrookStony BrookUSA

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