It has been well-known for over six decades that the addition of minute amounts of long polymer chains to organic solvents, or water, can lead to significant turbulent drag reduction. This discovery has had many practical applications such as in pipeline fluid transport, oil well operations, vehicle design and submersible vehicle projectiles, and more recently arteriosclerosis treatment. Howeve...

We report on the nonlinear turbulent processes associated with electromagnetic waves in plasmas. We focus on low-frequency (in comparison with the electron gyrofrequency) nonlinearly interacting electron whistlers and nonlinearly interacting Hall-magnetohydrodynamic (H-MHD) fluctuations in a magnetized plasma. Nonlinear whistler mode turbulence study in a magnetized plasma involves incompressib...

Measurements of turbulent fluctuations of horizontal and vertical components of velocity, salinity and suspended particulate matter are presented. Turbulent Prandtl numbers are found to increase with stratification and to become larger than 1. Consequently, the vertical turbulent mass transport is suppressed by buoyancy forces, before the turbulent kinetic energy (TKE) and vertical turbulent mo...

Dynamic models for large eddy simulation of the G-equation of turbulent premixed combustion are proposed and tested in forced homogeneous isotropic turbulence. The basic idea is to represent the ‘‘filtered propagation term’’ as ‘‘propagation of the filtered front at higher speed,’’ where the enhanced filtered-front speed is modeled. The validity of the linear relation between the turbulent flam...

Direct numerical simulation is used to study a round turbulent jet in a laminar crossflow. The ratio of bulk jet velocity to free-stream crossflow velocity is 5.7 and the Reynolds number based on the bulk jet velocity and the jet exit diameter is 5000. The mean velocity and turbulent intensities from the simulations are compared to data from the experiments by Su & Mungal (2004) and good agreem...

Heliospheric space plasmas are highly turbulent media and display multiscale fluctuations over a wide range of scales from the magnetohydrodynamic domain down to the kinetic one. The study of turbulence features is traditionally based on spectral and canonical structure function analysis. Here, we present an novel approach to the analysis of the multiscale nature of plasma turbulent fluctuation...

PURPOSE To assess turbulent kinetic energy (TKE) within the left ventricle (LV) of healthy subjects using novel 4D flow magnetic resonance imaging (MRI) methods and to compare TKE values to those from a limited group of patients with a spectrum of dilated cardiomyopathy (DCM). MATERIALS AND METHODS 4D flow and morphological MRI data were acquired in 11 healthy subjects and 9 patients with dif...

Observations of turbulent kinetic energy (TKE) dynamics in the ocean surface boundary layer are presented here and compared with results from previous observational, numerical, and analytic studies. As in previous studies, the dissipation rate of TKE is found to be higher in the wavy ocean surface boundary layer than it would be in a flow past a rigid boundary with similar stress and buoyancy f...

Energy equation for turbulent flow in a rotating system was derived in terms of second order correlation tensors, where the correlation tensors were functions of space coordinates, distance between two points and time. To reveal the relationship of turbulent energy between two points, one point was taken as origin of the coordinate system. Due to rotation, the Coriolis force played an important...