title: Small-scale turbulent fluctuations beyond Taylor's frozen-flow hypothesis.
abstract: The space-time cross-correlation function C(T)(r,τ) of local temperature fluctuations in turbulent Rayleigh-Bénard convection is obtained from simultaneous two-point time series measurements. The obtained C(T)(r,τ) is found to have the scaling form C(T)(r(E),0) with r(E)=[(r-Uτ)(2)+V(2)τ(2)](1/2), where U and V are two characteristic velocities associated with the mean and rms velocities of the flow. The experiment verifies the theory and demonstrates its applications to a class of turbulent flows in which the requirement of Taylor's frozen flow hypothesis is not met.
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: Guowei
authors.initials: G
authors.lastname: He
authors.forename: Penger
authors.initials: P
authors.lastname: Tong