title: Backwards and forwards relative dispersion in turbulent flow: an experimental investigation.
abstract: From particle tracking velocimetry we present an experimental measure of the ratio between backwards and forwards relative dispersion in an intermediate Reynolds number turbulent flow. Lack of time-reversal symmetry implies that their ratio may be different from 1. From a stochastic model, this has recently been studied by Sawford et al [Phys. Fluids 17, 095109 (2005)] giving ratios between 5 and 20. We find a value of approximately 2 and discuss it in the context of the characteristics of the rate of strain tensor s(ij). An analysis of a direct numerical simulation by Biferale et al [Phys. Rev. Lett. 93, 064502 (2004) and Phys. Fluids 17, 021701 (2004)] gives the same result.
authors.affiliation: Risø National Laboratory, 4000 Roskilde, Denmark. jacob.berg.joergensen@risoe.dk
authors.forename: Jacob
authors.initials: J
authors.lastname: Berg
authors.forename: Beat
authors.initials: B
authors.lastname: Lüthi
authors.forename: Jakob
authors.initials: J
authors.lastname: Mann
authors.forename: Søren
authors.initials: S
authors.lastname: Ott