title: Kraichnan's random sweeping hypothesis in homogeneous turbulent convection.
abstract: We report an experimental study of the temperature space-time cross-correlation function, C{T}(r,τ), in the central region of turbulent Rayleigh-Bénard convection. The measured C{T}(r,τ) is found to have the scaling form C{T}(r{E},0), where r{E}=[r² +(Vτ)²]¹/² with V being the rms velocity at the center of the convection cell. The experiment confirms the theory by He et al. [Phys. Rev. E 73, 055303(R) (2006)] and demonstrates its applications to homogenous turbulent flows, where the mean flow velocity is zero and Kraichnan's random sweeping hypothesis holds approximately.
authors.affiliation: Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Xiaozhou
authors.initials: X
authors.lastname: He
authors.forename: Penger
authors.initials: P
authors.lastname: Tong