Abstract
This paper presents an experimental investigation of the flow past a hemisphere-cylinder (a sphere whose lower half is replaced by a circular cylinder). The experiment was carried out in an N.P.L. blow-down type wind tunnel having a working section of 400 × 400 × 2000 mm in size at the Reynolds number 4.74 × 104.
The drag and lift coefficients were determined by integration of the surface pressure. By fitting a skirt to the lower half of a sphere placed on a ground plane, the drag coefficient was reduced by 7.5%. The velocity and pressure distributions and turbulence intensities in the turbulent shear flow behind a hemisphere-cylinder were measured. Since a hemisphere-cylinder is seen to be a hybrid of a sphere and a circular cylinder of aspect ratio one, the results for a hemisphere-cylinder were compared with those for a sphere and a circular cylinder of aspect ratio one.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
Abbreviations
- b :
-
Position of peak velocity defect [mm]
- C D :
-
Drag coefficient
- C L :
-
Lift coefficient
- C p :
-
Pressure coefficient \((P - {{P}_{\infty }})/(\rho U_{\infty }^{2}/2)\)
- D :
-
Diameter of cylinder [mm]
- H :
-
Height of cylinder [mm]
- n :
-
Frequency of vortex shedding [Hz]
- p :
-
Static pressure [Pa]
- P∞:
-
Free-stream pressure [Pa]
- P 0 :
-
Stagnation pressure [Pa]
- r :
-
Radial distance from center axis of cylinder [mm]
- Re:
-
Reynolds number = U∞D/υ
- St:
-
Strouhal number = nD/U∞
- U :
-
Time-mean velocity in X-direction [m/s]
- U ∞ :
-
Free-stream velocity [m/s]
- u′, v′ w′:
-
Velocity fluctuation in X, Y, Z direction [m/s]
- X, Y, Z :
-
Coordinate axes [mm]
- α:
-
Latitude angle [deg.]
- δ:
-
Thickness of shear layer [mm]
- θ:
-
Longitude angle [deg.]
- υ:
-
Kinematic viscosity of air [m2/s]
- ρ:
-
Density of air [kg/m3 ]
References
Hunt, J.C.R.: The effect of single buildings and structures. Philos. Trans. R. Soc. London A269, 457–467 (1971)
Peterka, J.A., Cermak, J.E.: “Turbulence in Building Wakes”, Proc. 4th Int. Conf. on Wind Effects on Building and Structures, 447-463 (1977)
Okamoto, T., Yagita, M.: The experimental investigation on the flow past a circular cylinder of finite length. Bull. Jpn. Soc. Mech. Eng. 16, 805–814 (1973)
Schlichting, H.: Experimentelle Untersuchungen zum Rauhigkeitsproblem. Ing. Arch. 7, 1–34 (1936)
Klemin, A., Schaefer, E.B., Beerer, J.G.: Aerodynamics of the perisphere and trylon at world’s fair. Trans. Am. Soc. Civ. Eng. 2042, 1449–1472 (1939)
Okamoto, S.: “Turbulent Shear Flow Behind a Sphere Placed on a Plane Boundary”, in: Turbulent Shear Flows 2, ed. by L.J.S. Bradbury, F. Durst, B.E. Launder, F.W. Schmidt, J.H. Whitelaw (Springer, Berlin Heidelberg New York 1980) 246–256
Sforza, P.M., Mons, R.F.: Wall-wake: Flow behind a leading edge obstacle. AIAA J. 8, 2162–2167 (1970)
Okamoto, T., Yagita, M., Kataoka, S.: Flow past cone placed on flat plate. Bull. Jpn. Soc. Mech. Eng. 20, 329–336 (1977)
Farell, C, Carrasquel, S., Giiven, O., Patel, V.C.: Effect of wind tunnel walls on the flow past circular cylinders and cooling tower models. Trans. ASME, Series I 99, 470-479 (1977)
Good, M.C., Joubert, P.N.: The form drag of two-dimensional bluff-plates immersed in turbulent boundary layers. J. Fluid Mech. 31, 547–582 (1968)
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1982 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Okamoto, S. (1982). Turbulent Shear Flow Behind Hemisphere-Cylinder Placed on Ground Plane. In: Bradbury, L.J.S., Durst, F., Launder, B.E., Schmidt, F.W., Whitelaw, J.H. (eds) Turbulent Shear Flows 3. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-95410-8_17
Download citation
DOI: https://doi.org/10.1007/978-3-642-95410-8_17
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-95412-2
Online ISBN: 978-3-642-95410-8
eBook Packages: Springer Book Archive