Abstract
An experimental study on the Reynolds stress tensor was conducted in the three-dimensional flow in the plane turbulent wall jet induced by an isolated streamwise vortex generated by the half-delta wing mounted on the wall. Oscillation of the angle of attack of the wing induced a periodic perturbation in the strength of the streamwise vortex. Analysis by triple velocity decomposition and phase averaging shows that the oscillation induces periodic variations in the strength, radius, and position of the streamwise vortex center. The effect of periodic perturbation manifests itself in the magnitude of the Reynolds stress components \(\overline{w^{2}}\) and \(\overline{vw}.\) Simulations prove that the periodic variations in the strength, radius, and position of the vortex center can generate an apparent shear stress, denoted herein as \(\overline{\tilde{V}\tilde{W}}.\)
Similar content being viewed by others
Abbreviations
- AR:
-
Aspect ratio of the jet nozzle, nozzle width/height
- b m :
-
Inner layer thickness of the plane wall jet (m or mm)
- b 2 :
-
Half-width of the plane wall jet (m or mm)
- c :
-
Chord length of the half-delta wing (m or mm)
- f :
-
Frequency of the oscillating wing (Hz)
- h :
-
Height of the half-delta wing (m or mm)
- R y :
-
Transverse radius of the streamwise vortex (m or mm)
- R z :
-
Spanwise radius of the streamwise vortex (m or mm)
- S l :
-
Nozzle height (m or mm)
- S yz :
-
Rate of strain in the cross-streamwise plane, \(=\frac{\partial W}{\partial y} + \frac{\partial V}{\partial z}\) (1/s)
- t′:
-
Delay time of phase averaging (s)
- T :
-
Period of oscillation of the angle of attack (s)
- U :
-
Mean streamwise velocity (m/s)
- U e :
-
Velocity in the irrotational flow outside the wall jet (m/s)
- U m :
-
Maximum mean streamwise velocity (m/s)
- U 0 :
-
Velocity excess, =U m − U e (m/s)
- u :
-
Fluctuating streamwise velocity (m/s)
- V :
-
Mean transverse velocity (m/s)
- v :
-
Fluctuating transverse velocity (m/s)
- W :
-
Mean spanwise velocity (m/s)
- w :
-
Fluctuating spanwise velocity (m/s)
- x :
-
Streamwise distance from the trailing edge of the wing (m or mm)
- x 0 :
-
Streamwise distance from the nozzle exit (m or mm)
- y :
-
Transverse distance from the wall (m or mm)
- y c :
-
Transverse distance from the wall to the vortex center (m or mm)
- z :
-
Spanwise distance from the centerline of the test plate (m or mm)
- z c :
-
Spanwise distance from the centerline to the vortex center (m or mm)
- α:
-
Angle of attack of the wing (degree)
- Ω x :
-
Mean streamwise vorticity, \( = \frac{\partial W}{\partial y} - \frac{\partial V}{\partial z}\) (1/s)
- ω x :
-
Fluctuating streamwise vorticity, \( = \frac{\partial w}{\partial y} - \frac{\partial v}{\partial z}\) (1/s)
- ΔT :
-
Time interval for conventional time averaging (s)
- ν:
-
Kinematic viscosity (m2/s)
- \(\overline{Q}\) :
-
Mean value, \(\equiv {\mathop {\lim}\limits_{\Delta T \to \infty}}\frac{1}{\Delta T}{\int\limits_{0}^{\Delta T} {\tilde{q}(t, {\mathbf{x}})\hbox{d}t}}\)
- 〈Q 〉 T :
-
Phase-averaged value, \( \equiv {\mathop {\lim}\limits_{N \to \infty}}\frac{1}{N}{\sum\limits_{k = 0}^{N - 1} {\tilde{q}({\mathbf{x}, }t + kT)}}\)
- \(\tilde{Q}\) :
-
Periodic fluctuating component of \(\tilde{Q}\)
- q′:
-
Random fluctuating component of \(\tilde{Q}\)
- \(\tilde{Q}\) :
-
Instantaneous value of the physical quantity q
References
Baker GR, Barker SJ, Bofah KK, Saffman PG (1974) Laser anemometer measurements of trailing vortices in water. J Fluid Mech 65(2):325–336
Bradshaw P (1987) Turbulent secondary flows. Annu Rev Fluid Mech 19:53–74
Bruun HH (1995) Hot-wire anemometry. Oxford University Press, Oxford, pp 176–180
Bushnell DM (1983) Body–turbulence interaction. AIAA Paper, pp 83–1527
Chow JS, Bradshaw P (1997) Mean and turbulence measurements in the near field of a wingtip vortex. AIAA J 35(10):1561–1567
Irwin HPAH (1973) Measurements in a self-preserving plane wall jet in a positive pressure gradient. J Fluid Mech 61(1):33–63
Mochizuki S, Osaka H (1999) Management of a stronger wall jet by an embedded streamwise vortex: Reynolds stress distributions and evaluation of the vorticity transport equation. JSME Int J 42(1):1–8
Mochizuki S, Yamada S, Osaka H (2004) Active management of a stronger wall jet by a streamwise vortex. Int J Transport Phenomena 6:213–223
Reynolds WC, Hussain AKMF (1972) The mechanics of an organized wave in turbulent shear flow part 3: theoretical models and comparisons with experiments. J Fluid Mech 54(2):263–288
Russ S, Simon TW (1991) On the rotating, slanted, hot-wire technique. Exp Fluids 12:76–80
Tennekes H, Lumley JL (1972) A first course in turbulence. The MIT Press, Cambridge, p 84
Townsend AA (1976) The structure of turbulent shear flow, 2nd edn. Cambridge University Press, Cambridge, p 329
Westphal RV, Mehta RD (1989) Interaction of an oscillating vortex with a turbulent boundary layer. Exp Fluids 7:405–411
Yavuzkurt S (1984) A guide to uncertainty analysis of hot-wire data. Trans ASME J Fluids Eng 106:181–186
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Mochizuki, S., Yamada, S. & Osaka, H. Reynolds stress field in a turbulent wall jet induced by a streamwise vortex with periodic perturbation. Exp Fluids 40, 372–382 (2006). https://doi.org/10.1007/s00348-005-0074-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00348-005-0074-9