The nonlinear coefficients defining the mean electromotive force (i.e., the nonlinear turbulent magnetic diffusion, the nonlinear effective velocity, the nonlinear kappa tensor, etc.) are calculated for an anisotropic turbulence. A particular case of an anisotropic background turbulence (i.e., the turbulence with zero-mean magnetic field) with one preferential direction is considered. It is sho...

The scale interactions occurring within a turbulent boundary layer are investigated in the presence of free-stream turbulence. The free-stream turbulence is generated by an active grid. The free stream is monitored by a single-component hot-wire probe while a second probe is roved across the height of the boundary layer at the same streamwise location. Large-scale structures occurring in the fr...

In recent years, the use of offshore wind turbines has been considered on the agenda of the countries which have a significant maritime boundary due to more speed and stability of wind at sea. The aim of this study is to investigate the effect of wind turbulence on the aero-hydrodynamic behavior of offshore wind turbines with a monopile platform. Since in the sea, the wind turbine structures ar...

In this study, turbulent compressible gas flow in a rectangular micro-channel is numerically investigated. The gas flow assumed to be in the subsonic regime up to Mach number about 0.7. Five low and high Reynolds number RANS turbulence models are used for modeling the turbulent flow. Two types of mesh are generated depending on the employed turbulence model. The computations are performed for R...

There are a number of systems in which supercritical cryogenic fluids are used as coolants or propellant fluids. In some modern military aircraft, the fuel is pressurized above its critical point and used as a coolant to remove heat from the aircraft engine. Accurate prediction of heat transfer coefficients to turbulent flows of supercritical fluids is essential in design of such systems. One o...

Tropospheric scintillation is caused by variations of refractive index due to turbulence. The only meteorological input parameter for two common current scintillation models by Karasawa et al. and by ITU-R is the monthly average of wet part of refractivity Nwet at ground level, which is not directly associated with turbulence. The diurnal correlation betweenNwet and scintillation variance is ve...

J. C. Li and P. H. Diamond CMTFO and CASS, University of California, San Diego, California 92093, USA Abstract Negative compressibility ITG turbulence in a linear plasma device (CSDX) can induce a negative viscosity increment. However, even with this negative increment, we show that the total axial viscosity remains positive definite, i.e. no intrinsic axial flow can be generated by pure ITG tu...

Turbulence properties in the scrape-off layer (SOL) in the presence of ion cyclotron frequency heating (ICRH) are compared to instances where it is absent. The discharges are all in a high-confinement mode (H-mode) regime. During ICRH, the SOL plasma density increases whereas turbulence large-scale and convective structures are shown to be suppressed. The probability distribution function is th...

Environmental turbulence is ubiquitous in natural habitats, but its effect on flying animals remains unknown because most flight studies are performed in still air or artificially smooth flow. Here we show that variability in external airflow limits maximum flight speed in wild orchid bees by causing severe instabilities. Bees flying in front of an outdoor, turbulent air jet become increasingly...

The transition from weak to strong turbulence when passing from large to small scales in magnetohydrodynamic (MHD) turbulence with guide field is a cornerstone of anisotropic turbulence theory. We present the first check of this transition, using the Shell-RMHD, which combines a shell model of perpendicular nonlinear coupling and linear propagation along the guide field. This model allows us to...