[1] Two deep ocean hotspots of turbulent mixing were found over the Oregon continental slope. Thorpe-scale analyses indicate time-averaged turbulent energy dissipation rates of > 10 7 W/kg and eddy diffusivities of Kr 10 2 m/s at both hotspots. However, the structure of turbulence and its generation mechanism at each site appear to be different. At the 2200-m isobath, sustained >100-m high turb...

The theory of compressible MHD (e.g., Alfvénic) turbulence has been a topic of interest for some time [1]. Alfvén wave turbulence presents several novel challenges, due to the fact the k–ω selection rules preclude three Alfvén-wave resonance. Thus, in incompressible MHD, two Alfvén waves can interact only with the vortex (i.e., eddy) mode. Compressibility relaxes this constraint by allowing int...

‎Let $D$ be an integral domain with quotient field $K$‎, ‎$E$ be a $K$-vector space‎, ‎$R = D propto E$ be the trivial extension of $D$ by $E$‎, ‎and $w$ be the so-called $w$-operation‎. ‎In this paper‎, ‎we show that‎ ‎$R$ is a $w$-FF ring if and only if $D$ is a $w$-FF domain; and‎ ‎in this case‎, ‎each $w$-flat $w$-ideal of $R$ is $w$-invertible.

Bridges are very important for establishing communication paths. For this reason, it is important to control scour around bridge piers. Several methods have been proposed for scour control. One of the most useful methods is the use of submerged vanes. In the other hand, laboratory circumstances force many considered effective factors to be skipped in the scour phenomenon. In this situation, the...

The RANS ~Reynolds averaged Navier–Stokes! equations can yield significant error when applied to practical flows involving shock waves. We use the interaction of homogeneous isotropic turbulence with a normal shock to suggest improvements in the k – e model applied to shock/ turbulence interaction. Mahesh et al. @J. Fluid Mech. 334, 353 ~1997!# and Lee et al. @J. Fluid Mech. 340, 22 ~1997!# pre...

Based on the physics underlying turbulence anisotropy in the equilibrium and nonequilibrium limits, a new physically-based, fully-realizable, nonequilibrium k − 2 RANS model has been developed. The model is based on an effective strain rate tensor that accounts for the strain history to which the turbulence has been subjected. This new model is applied to four distinctly different test cases fo...

Turbulence calculations with a 3D collisional fluid plasma model demonstrate qualitative and semi-quantitative similarity to experimental data in the Large Plasma Device [W. Gekelman et al., Rev. Sci. Inst. 62, 2875 (1991)], in particular for the temporal spectra, fluctuations amplitude, spatial correlation length, and radial particle flux. Several experimentally observed features of plasma tur...

The present investigation concerns the development of advanced scalar turbulence modeling approaches and their application to the calculation of non-isothermal wall-bounded flow phenomena. A new scalar modeling technique based on scalar turbulent scales is proposed and implemented at a second-order modeling approach. Instead of the classical analogy concept between the mechanical and the scalar...

We analyze the time reversal of waves in a turbulent medium using the parabolic Markovian model. We prove that for waves in a fractal medium with a sufficiently small Fresnel number the time reversal resolution can be a nonlinear (between linear and quadratic) function of the wavelength and independent of the aperture. We establish the duality between the forward propagation and time reversal. ...

The RANS (Reynolds averaged Navier-Stokes) equations can yield significant error when applied to practical flows involving shock waves. We use the interaction of homogeneous isotropic turbulence with a normal shock to suggest improvements in the k− model applied to shock/turbulence interaction. Mahesh et al. and Lee et al. present direct numerical simulation (DNS) and linear analysis of the flo...