A priori analysis of the performance of cross hot-wire probes in a rough wall boundary layer based on stereoscopic PIV
Error in measuring Reynolds shear-stress in turbulent boundary layer flows over a rough surface with a cross hot-wire has been reported in the literature and attributed to the existence of strong ejection and sweep motions that cause rectification, e.g. deviation of the velocity vector angle outside the acceptance cone of these probes. Using stereoscopic particle image velocimetry measurements and the concept of effective cooling velocities, the objective of the present study is to perform an a priori analysis of the cause of errors occurring when employing cross hot-wire anemometers. Besides the above-mentioned rectification effect, the role of the non-measured component is investigated. It is shown to be responsible for a non-negligible underestimation of the measured velocity variances and Reynolds shear-stress. This often overlooked source of error is intrinsic to turbulent flows and not limited to flow over rough walls.
- Blackman K, Perret L, Calmet I, Rivet C (2017) Turbulent kinetic energy budget in the boundary layer developing over an urban-like rough wall using PIV. Phys Fluids 29(085):113Google Scholar
- Bruun HH (1995) Hot-wire anemometry, principles and signal analysis. Oxford Science Publications, OxfordGoogle Scholar
- Perret L, Basley J, Mathis R, Piquet T (2018) Atmospheric boundary layers over urban-like terrains: influence of the plan density on the roughness sublayer dynamics. Bound Layer Meteorol (Accepted)Google Scholar
- Perret L, Piquet T, Basley J, Mathis R (2017) Effects of plan area densities of cubical roughness elements on turbulent boundary layers. In: Congrès Français de Mécanique, pp 1–12. https://cfm2017.sciencesconf.org/130816. Accessed 28 Aug 2017
- Rivet C (2014) Etude en soufflerie atmosphérique des interactions entre canopée urbaine et basse atmosphère par PIV stéréoscopique. Ph.D. thesis, Ecole Centrale de NantesGoogle Scholar