Abstract
We use grid-generated turbulence as a benchmark flow to test the effects of spatial resolution on turbulence measurements with hot wires. To quantify the spatial filtering, measurements of the turbulence statistics and spectra downstream of the grid were made using hot wires of varying length and compared to the results from a new nanoscale thermal anemometry probe, which has a sensing length of the order of, or smaller than, the Kolmogorov scale. In order to separate the effects of temporal and spatial filtering, a study was performed to ensure that the data were free of the artifacts of temporal filtering so that differences in the measurements could be wholly attributed to spatial filtering. An empirical correlation for the attenuation of the streamwise Reynolds stress due to spatial filtering is constructed, and it is shown that these grid turbulence results relate directly to the near-wall region of wall-bounded flows, where the effects of spatial filtering are most acutely felt. The effect of spatial filtering on the streamwise spectrum function is observed to extend to almost all wavenumbers, even those significantly lower than the length of the hot wire itself. It is also shown that estimates of the Kolmogorov scale are affected by spatial filtering when wires longer than the Kolmogorov length are used.
Similar content being viewed by others
References
Bailey S, Kunkel G, Hultmark M, Vallikivi M, Hill J, Meyer K, Tsay C, Arnold C, Smits A (2010) Turbulence measurements using a nanoscale thermal anemometry probe. J Fluid Mech 663:160–179
Cameron J, Morris S, Bailey S, Smits A (2010) Effects of hot-wire length on the measurement of turbulent spectra in anisotropic flows. Meas Sci Technol 21:105–407
Chin C, Hutchins N, Ooi A, Marusic I (2009) Use of direct numerical simulation (dns) data to investigate spatial resolution issues in measurements of wall-bounded turbulence. Meas Sci Technol 20:115–401
Dryden HL, Mock GBSGB, Skramstad WC (1937) Measurements of intensity and scale of wind-tunnel turbulence and their relation to the critical reynolds number of spheres. Natl Adv Comm Aeronaut Tech. Rep. 581
Elsner JW, Domagala P, Elsner W (1992) Effect of finite spatial resolution of hot-wire anemometry on measurements of turbulence energy dissipation. Meas Sci Technol 4:517–523
George JCW (1997) The reduction of spatial aliasing by long hot-wire anemometer probes. Exp Fluids 23:217–224
Hultmark M, Ashok A, Smits A (2011) A new criterion for end-conduction effects in hot-wire anemometry. Meas Sci Technol 22:55,401–55,405
Hutchins N, Nickels T, Marusic I, Chong M (2009) Hot-wire spatial resolution issues in wall-bounded turbulence. J Fluid Mech 635:103–136
Ligrani P, Bradshaw P (1987) Spatial resolution and measurement of turbulence in the viscous sublayer using subminiature hot-wire probes. Exp Fluids 5:407–417
McKeon B, Comte-Bellot G, Foss JF, Westerweel J, Scarano F, Tropea C, Meyers JF, Lee J, Cavone A, Schodl R, Koochesfahani M, Nocera D, Andreopoulos Y, Dahm J, Mullin J, Wallace J, Vukoslavecević P, Morris S, Pardyjak E, Cuerva A (2007) Springer handbook of experimental fluid mechanics, Springer, chap Velocity, Vorticity and Mach Number, pp 215–471
Pope S (2007) Turbulent flow. Spinger, New York
Smits AJ, Monty J, Hultmark M, Marusic I, Chong M (2011) Spatial resolution correction for wall-bounded turbulence measurements. J Fluid Mech 676:41–53
Tennekes, Lumley (1972) A first course in turbulence. The MIT Press, Cambridge
Vallikivi M, Hultmark M, Bailey SCC, Smits AJ (2011) Turbulence measurements in pipe flow using a nano-scale thermal anemometry probe. Exp Fluids 51(6):1521–1527
Yakhot V, Bailey S, Smits A (2010) Scaling of global properties of turbulence and skin friction in pipe and channel flows. J Fluid Mech 652:65–73
Acknowledgments
This work was supported by ONR Grant N00014-09-1-0263 (Program Manager Ron Joslin) and NSF Grant CBET-1064257 (Program Manager Henning Winter). Margit Vallikivi provided the NSTAP probes and Mike Vocaturo and Glenn Northey generously gave their technical assistance.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ashok, A., Bailey, S.C.C., Hultmark, M. et al. Hot-wire spatial resolution effects in measurements of grid-generated turbulence. Exp Fluids 53, 1713–1722 (2012). https://doi.org/10.1007/s00348-012-1382-5
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00348-012-1382-5