Turbulence over arrays of obstacles in low temperature helium gas
Laboratoire de Physique Statistique, École Normale
Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
Revised: 28 August 2000
Published online: 15 November 2000
Turbulence produced in low temperature helium gas flowing over arrays of rectangular- and triangular-shaped blunt obstacles is investigated experimentally. The set-up allows both low fluctuation rates (down to 8% ), and high microscale Reynolds numbers, (up to 1 150). The forced Kolmogorov equation is found to apply accurately. Similar to another flow configuration (counter rotating flow case ), the analysis of the flatness factor evolution with the Reynolds number reveals a transitional behavior around 650.
PACS: 47.27.Gs – Isotropic turbulence; homogeneous turbulence / 47.27.Jv – High-Reynolds-number turbulence
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000