Similarity of intermittency characteristics of temperature and transverse velocity

The intermittency characteristics of the longitudinal (u) and transverse (v) velocity and temperature (θ) at similar Taylor microscale Reynolds numbers have been compared in a turbulent round jet. We examine the scaling exponents ζα(n) (α=u, v, and θ) of structure functions <(δα)>n, the intermittency exponents µα based on individual and mixed sixth-order structure functions, the scaling exponents ζα(n) of the locally averaged energy and temperature dissipation rates approximated by (δα/δx)2, the flatness factors of the derivatives δα/δx, and the probability density functions (PDFs) of δα/δx, the increment δα and (δα/δx)2. It is found that v and θ are similar in terms of their intermittency characteristics. They are more intermittent than u. The scaling exponent ζv(n) is marginally larger than ζθ(n). The intermittency exponent µθ is smaller than µv based on the estimate of mixed sixth-order structure functions, while µθ is nearly equal to µv based on the estimate of individual sixth-order structure functions. The temperature dissipation rate is more intermittent than the turbulent energy dissipation rate, as indicated by τα(n). The flatness factor of δθ/δx is marginally larger than that of δv/δx. The PDFs of δθ/δx, deltaθ, and (δθ/δx)2 show the strongest departure from the Gaussian distribution.