The influence of temperature fluctuations on hot-wire measurements in wall-bounded turbulence
Orlu R, Malizia F, Cimarelli A, Schlatter P, Talamelli A (2014)
Publication Type: Journal article
Publication year: 2014
Journal
Book Volume: 55
Article Number: 1781
Journal Issue: 7
DOI: 10.1007/s00348-014-1781-x
Abstract
There are no measurement techniques for turbulent flows capable of reaching the versatility of hot-wire probes and their frequency response. Nevertheless, the issue of their spatial resolution is still a matter of debate when it comes to high Reynolds number near-wall turbulence. Another, so far unattended, issue is the effect of temperature fluctuations - as they are, e.g. encountered in non-isothermal flows - on the low and higher-order moments in wall-bounded turbulent flows obtained through hot-wire anemometry. The present investigation is dedicated to document, understand, and ultimately correct these effects. For this purpose, the response of a hot-wire is simulated through the use of velocity and temperature data from a turbulent channel flow generated by means of direct numerical simulations. Results show that ignoring the effect of temperature fluctuations, caused by temperature gradients along the wall-normal direction, introduces - despite a local mean temperature compensation of the velocity reading - significant errors. The results serve as a note of caution for hot-wire measurements in wall-bounded turbulence, and also where temperature gradients are more prevalent, such as heat transfer measurements or high Mach number flows. A simple correction scheme involving only mean temperature quantities (besides the streamwise velocity information) is finally proposed that leads to a substantial bias error reduction. © 2014 Springer-Verlag Berlin Heidelberg.
Authors with CRIS profile
Involved external institutions
Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH)
Sweden (SE)
University of Bologna / Università di Bologna
Italy (IT)
Sweden (SE)
University of Bologna / Università di Bologna
Italy (IT)
How to cite
APA:
Orlu, R., Malizia, F., Cimarelli, A., Schlatter, P., & Talamelli, A. (2014). The influence of temperature fluctuations on hot-wire measurements in wall-bounded turbulence. Experiments in Fluids, 55(7). https://doi.org/10.1007/s00348-014-1781-x
MLA:
Orlu, Ramis, et al. "The influence of temperature fluctuations on hot-wire measurements in wall-bounded turbulence." Experiments in Fluids 55.7 (2014).
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