Abstract
Isotropic turbulence is closely approximated by stretching a grid flow through a short (1.36:1) secondary contraction. The flow is operated at small values of the Taylor microscale Reynolds number (about 25–55) and is slightly heated just downstream of the grid, so that the temperature serves as a passive scalar and the initial velocity/thermal length-scale ratio is about 1. For the same grid, the contraction reduces the skewness and kurtosis of the thermal fluctuations and their derivative. The thermal fluctuations and their mean dissipation rates follow a power-law rate of decay that depends on the geometry of the grid. Comparison with velocity measurements shows that, for three different grids, the ratio between the temperature and velocity power-law exponents closely matches the velocity/thermal timescale ratio. For the present measurements, the timescale ratio is slightly larger than 1 but does not exceed 1.2, in accordance with the proposal by Corrsin (J Aeronaut Sci 18(6):417–423, 1951b).
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References
Antonia RA, Browne LWB, Chambers AJ (1981) Determination of time constants of cold wires. Rev Sci Instrum 52(9):1382–1385
Antonia RA, Chambers AJ, Van Atta CW, Friehe CA, Helland KN (1978) Skewness of temperature derivative in a heated grid flow. Phys Fluids 21(3):509–510
Antonia RA, Lavoie P, Djenidi L, Benaissa A (2010) Effect of a small axisymmetric contraction on grid turbulence. Exp Fluids 49:3–10
Antonia RA, Smalley RJ, Zhou T, Anselmet F, Danaila L (2004) Similarity solution of temperature structure functions in decaying homogeneous isotropic turbulence. Phys Rev E 69:016305
Batchelor GK (1953) The theory of homogeneous turbulence. Cambridge University Press, Cambridge
Batchelor GK, Proudman I (1956) The large-scale structure of homogeneous turbulence. Proc R Soc Lond Ser A Math Phys Sci 248(949):369–405
Comte-Bellot G, Corrsin S (1966) The use of a contraction to improve the isotropy of grid-generated turbulence. J Fluid Mech 25(4):657–682
Comte-Bellot G, Corrsin S (1971) Simple Eulerian time correlation of full- and narrow-band velocity signals in grid-generated, ‘isotropic’ turbulence. J Fluid Mech 48(2):273–337
Corrsin S (1951a) On the spectrum of isotropic temperature fluctuations in an isotropic turbulence. J Appl Phys 22(4):469–473
Corrsin S (1951b) The decay of isotropic temperature fluctuations in an isotropic turbulence. J Aeronaut Sci 18(6):417–423
Dryden HL (1943) A review of the statistical theory of turbulence. Q Appl Math 1:7–42
Durbin PA (1980) A stochastic model of two-particle dispersion and concentration fluctuations in homogeneous turbulence. J Fluid Mech 100(2):279–302
Durbin PA (1982) Analysis of the decay of temperature fluctuations in isotropic turbulence. Phys Fluids 25(8):1328–1332
George WK (1992a) Self-preservation of temperature fluctuations in isotropic turbulence. In: Gatski TB, Sarkar S, Speziale CG (eds) Studies in turbulence. Springer, New York, pp 514–528
George WK (1992b) The decay of homogeneous isotropic turbulence. Phys Fluids 4(7):1492–1509
George WK, Wang H, Wollblad C, Johansson TG (2001) ‘Homogeneous turbulence’ and its relation to realizable flows. In: Dally BB (ed) Proceedings of the 14th Australas. Fluid mechanics conference. Adelaide, Australia, pp 41–48
Kármán T, Howarth L (1938) On the statistical theory of isotropic turbulence. Proc R Soc Lond Ser A Math Phys Sci 164(917):192–215
Krogstad PÅ, Davidson PA (2010) Is grid turbulence Saffman turbulence?. J Fluid Mech 642:373–394
Lavoie P (2006) Effects of initial conditions on decaying grid turbulence. Ph.D. Thesis, University of Newcastle, Newcastle, Australia
Lavoie P, Djenidi L, Antonia RA (2007) Effects of initial conditions in decaying turbulence generated by passive grids. J Fluid Mech 585:395–420
Mills RR, Corrsin S (1959) Effect of contraction on turbulence and temperature fluctuations generated by a warm grid. Memo 5-5-59W, National Aeronautics and Space Administration.
Mills RR, Kistler AL, O’Brien V, Corrsin S (1958) Turbulence and temperature fluctuations behind a heated grid. Tech. Note 4288, National Advisory Committee for Aeronautics
Mohamed MS, LaRue JC (1990) The decay power law in grid-generated turbulence. J Fluid Mech 219:195–214
Monin AS, Yaglom AM (1975) Statistical fluid mechanics: mechanics of turbulence, vol 2. The MIT Press, Cambridge
Mydlarski L, Warhaft Z (1996) On the onset of high-Reynolds-number grid-generated wind tunnel turbulence. J Fluid Mech 320:331–368
Mydlarski L, Warhaft Z (1998) Passive scalar statistics in high-Péclet-number grid turbulence. J Fluid Mech 358:135–175
Prandtl L (1933) Attaining a steady air stream in wind tunnels. Tech. Memo 726, National Advisory Committee for Aeronautics
Saffman PG (1967) The large-scale structure of homogeneous turbulence. J Fluid Mech 27(3):581–593
Sawford BL (2004) Micro-mixing modelling of scalar fluctuations for plumes in homogeneous turbulence. Flow Turb Comb 72:133–160
Sawford BL, Hunt JCR (1986) Effects of turbulence structure, molecular diffusion and source size on scalar fluctuations in homogeneous turbulence. J Fluid Mech 165:373–400
Sepri P (1976) Two-point turbulence measurements downstream of a heated grid. Phys Fluids 19(12):1876–1884
Sirivat A, Warhaft Z (1983) The effect of a passive cross-stream temperature gradient on the evolution of temperature variance and heat flux in grid turbulence. J Fluid Mech 128:323–346
Sreenivasan KR, Tavoularis S, Henry R, Corrsin S (1980) Temperature fluctuations and scales in grid-generated turbulence. J Fluid Mech 100(3):597–621
Taylor GI (1921) Diffusion by continuous movements. Proc Lond Math Soc 20(1):196–212
Taylor GI (1935a) Statistical theory of turbulence 4—diffusion in a turbulent air stream. Proc R Soc Lond Ser A Math Phys Sci 151(873):465–478
Taylor GI (1935b) Turbulence in a contracting stream. Z Angew Math Mech 15:91–96
Tennekes H, Lumley JL (1972) A first course in turbulence. The MIT Press, Cambridge
Tong C, Warhaft Z (1994) On passive scalar derivative statistics in grid turbulence. Phys Fluids 6(6):2165–2176
Uberoi MS (1956) Effect of wind-tunnel contraction on free-stream turbulence. J Aeronaut Sci 23(8):754–764
Viswanathan S, Pope SB (2008) Turbulent dispersion from line sources in grid turbulence. Phys Fluids 20:101514
Warhaft Z (1980) An experimental study of the effect of uniform strain on thermal fluctuations in grid-generated turbulence. J Fluid Mech 99(3):545–573
Warhaft Z (1984) The interference of thermal fields from line sources in grid turbulence. J Fluid Mech 144:363–387
Warhaft Z (2000) Passive scalars in turbulent flows. Ann Rev Fluid Mech 32:203–240
Warhaft Z, Lumley JL (1978) An experimental study of the decay of temperature fluctuations in grid-generated turbulence. J Fluid Mech 88(4):659–684
Yeh TT, Van Atta CW (1973) Spectral transfer of scalar and velocity fields in heated-grid turbulence. J Fluid Mech 58(2):233–261
Zhou T, Antonia RA, Chua LP (2002) Performance of a probe for measuring turbulent energy and temperature dissipation rates. Exp Fluids 33:334–345
Zhou T, Antonia RA, Danaila L, Anselmet F (2000) Transport equations for the mean energy and temperature dissipation rates in grid turbulence. Exp Fluids 28:143–151
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The authors gratefully acknowledge the financial support of the Australian Research Council and the Natural Sciences and Engineering Research Council of Canada.
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Lee, S.K., Benaissa, A., Djenidi, L. et al. Decay of passive-scalar fluctuations in slightly stretched grid turbulence. Exp Fluids 53, 909–923 (2012). https://doi.org/10.1007/s00348-012-1331-3
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DOI: https://doi.org/10.1007/s00348-012-1331-3