TY - JOUR

T1 - Similarity of intermittency characteristics of temperature and transverse velocity

AU - Xu, G.

AU - Zhou, Tongming

AU - Rajagopalan, S.

PY - 2007

Y1 - 2007

N2 - 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 τα(n) of the locally averaged energy and temperature dissipation rates approximated by (∂α∕∂x)2, the flatness factors of the derivatives ∂α∕∂x, and the probability density functions (PDFs) of ∂α∕∂x, the increment δα and (∂α∕∂x)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 ∂θ∕∂x is marginally larger than that of ∂v∕∂x. The PDFs of ∂θ∕∂x, δθ, and (∂θ∕∂x)2 show the strongest departure from the Gaussian distribution.

AB - 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 τα(n) of the locally averaged energy and temperature dissipation rates approximated by (∂α∕∂x)2, the flatness factors of the derivatives ∂α∕∂x, and the probability density functions (PDFs) of ∂α∕∂x, the increment δα and (∂α∕∂x)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 ∂θ∕∂x is marginally larger than that of ∂v∕∂x. The PDFs of ∂θ∕∂x, δθ, and (∂θ∕∂x)2 show the strongest departure from the Gaussian distribution.

U2 - 10.1103/PhysRevE.76.046302

DO - 10.1103/PhysRevE.76.046302

M3 - Article

VL - 76

SP - Article number 046302

JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

SN - 1539-3755

IS - 4

ER -