Skip to main content
SpringerLink
Log in

Measurement of the viscous sublayer in near-separated flows

  • Published:
Applied Scientific Research Aims and scope Submit manuscript

Abstract

This paper investigates experimentally the development of the viscous sublayer in a two-dimensional incompressible turbulent wall boundary layer under severe pressure gradients. The wall was also moderately heated and the influence of heat transfer on the development of the viscous sublayer was included.

A semi-empirical equation for the thickness of the viscous sublayer:

$$\delta _s = 11.5\frac{\nu }{{U_\tau }}(0.61\frac{{T_\omega }}{{T_s }})^{1/2}$$

was derived, which holds everywhere except closely near the separation point of the boundary layer.

The measurements were made on a flat plate in a test section 1.7 m long and 0.8 m wide. The height and shape of the top surface of the test section could be varied, and thus it was possible to imposed different pressure gradients on the flow. Specially designed fine probes facilitated the measurement of the velocity distribution very close to the wall.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

Abbreviations

A :

constant

B :

constant

C f :

friction coefficient =2τ w /(ρ ρU 2 δ )

L :

length of the flat plate (L=1700 mm)

P :

static pressure

P dyn :

dynamic pressure

Re:

Reynolds number

T w :

wall temperature

T δ :

temperature at the edge of the boundary layer

U :

velocity

T τ :

shear velocity =(τ w /ρ)1/2

U + :

U/U τ

U s :

velocity at the edge of viscous sublayer

U δ :

velocity at the edge of boundary layer

X, Y :

coordinates in flow direction and normal to it

Y + :

\(Y\frac{{U_\tau }}{\nu }\)

δ :

nominal thickness of boundary layer

δ 1 :

displacement thickness of boundary layer

δ s :

thickness of viscous sublayer

ν :

kinematic viscosity of air

ρ :

density of air

Π:

pressure gradient parameter \(\frac{{dp}}{{dx}} \cdot \frac{{\delta _1 }}{{\tau _\omega }}\)

τ w :

shear stress at the surface of the plate

References

  1. Brown KC and Joubert PN (1969) The measurement of skin friction in turbulent boundary layer with adverse pressure gradient. J Fluid Mechanics 35 (4).

  2. Daugherty R and Franzini J (1977) Fluid Mechanics with Engineering Applications. McGraw Hill Book Co.

  3. Einstein HA and Li H (1956) The viscous sublayer along a smooth boundary. Proceedings ASCE 82.

  4. Hebbar SK and Melnik WL (1975) Experimental studies of near wall region of a 3-dimensional low-speed turbulent boundary layer. Bulletin of the American Physical Society V20.

  5. Popovich AT (1967) Experimental study of the viscous sublayer in turbulent pipe. AICHE Journal 14 (4).

  6. Rechenberg I (1963) Messung der turbulenten Wandschubspannung. Zeitschrift für Flugwissenschaften II.

  7. Rechenberg I, Schwefel HP and Bienert P (1962) Messung kleiner Wandschubspannungen bie turbulenten Grenzschichten in Ablösenahe. Unpublished report at HFI, Technical University, Berlin.

    Google Scholar 

  8. Rotta J (1962) Boundary Layer Problems. Progress in Aeronautical Sciences, Vol 2. Pergamon Press.

  9. Rubesin MW (1953) A modified Reynolds analogy for the compressible turbulent boundary layer on a flat plate. NACA TN 2917.

  10. Rubesin MW, Murphy JD and Rose WC (1974) Wall shear in strongly retarded and separated compressible turbulent boundary layers. AIAA Journal 12 (April).

  11. Salam MY (1971) Beigtrag zur experimentellen Untersuchung des Wärmeübergangs in einer turbulenten Wandgrenzschicht in Bereich eines starken Druckanstiegs. Dissertation, Technical University, Berlin.

    Google Scholar 

  12. Salam MY (1980) Experimental Measurements of Flow Characteristics and Heat Transfer in an Incompressible Turbulent Wall Boundary layer. Proceedings of the First Asian Conference for Fluid Mechanics, A-13.

  13. Schigemitsu Y (1957) Experimental studies on laminar sublayer in turbulent boundary layer involving separation. J Phys Soc Japan 12.

  14. Sokolov M, Hussain AKMF, Kleis SJ and Husain ZD (1980) A ‘turbulent spot’ in an axisymmetric free shear layer. JFM 98 (I):65–95; 98 (II):97–135.

    Google Scholar 

  15. Wygnanski I, Haritomidis JH and Kaplan RE (1980) Coherent structures of turbulent boundary layer. JFM 92:505–528.

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Mechanical Engineering Department, College of Engineering and Petroleum, Kuwait University, Kuwait

    Mohammad Yahya Salam

Authors
  1. Mohammad Yahya Salam
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Salam, M.Y. Measurement of the viscous sublayer in near-separated flows. Applied Scientific Research 39, 337–347 (1982). https://doi.org/10.1007/BF00389270

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00389270

Keywords

Search

Navigation