Plasma zonal-flow excitation and saturation in fluid electron-drift-wave turbulence are studied spectrally. The zonal flow is a spectral condensation onto the zero-frequency linear-wave structure. In the representation diagonalizing the wave coupling that dominates interactions at long wavelengths, nonlinear triad interactions involving zero-frequency waves are greatly enhanced. Zonal modes are...

The interaction of a laser-induced plasma with isotropic turbulence is studied using numerical simulations. The simulations use air as the working fluid and assume local thermodynamic equilibrium. The numerical method is fully spectral and uses a shockcapturing scheme in a corrector step. A model problem involving the effect of energy deposition on an isolated vortex is studied as a first step ...

in this study, fluid flow and energy separation in a micro-scale ranque-hilschvortex tube are numerically investigated. the flow is assumed as 2d, steady,compressible ideal gas, and shear-stress-transport sst k-w is found to be a bestchoice for modeling of turbulence phenomena. the results are in a good agreementwith the experimental results reported in the literature. the results show that flu...

If an air flow is injected into a liquid fluid, many ambulant air bubbles are formed inside the fluid. Air bubbles move inside the liquid fluid because of the buoyancy force, and the mobility of these air bubbles makes sizable commixture and turbulence inside the fluid. This mechanism was employed to enhance the heat transfer rate of a horizontal double pipe heat exchanger in this paper. Howeve...

Characteristics of rotor blade tip clearance flow in axial compressors can significantly affect their performance and stable operation. It may also increase blade vibrations and cause detrimental noises. Therefore, this paper is contributed to investigate tip leakage flow in a low speed isolated axial compressor rotor blades row. Simulations are carried out on near-stall condition, which is val...

Among the many force s to which hydraulic structures are exposed to, the forces induced by cavitation incident are of typical hydrodynamic unknown forces. The aim of this study is to define these forces as coupled fluid-structure interaction under two dynamic effects. The first dynamic effect which incorporates facilities for dealing with cavitation fluid is based on the appearance and bursting...

Particles suspended in turbulent flows are affected by the turbulence and at the same time act back on the flow. The resulting coupling can give rise to rich variability in their dynamics. Here we report experimental results from an investigation of finite-sized buoyant spheres in turbulence. We find that even a marginal reduction in the particle's density from that of the fluid can result in s...

Concentric mixing experiments with velocity ratios of up to 6 have been completed using hardwood pulp of 1.0, 1.9, and 2.9% consistency and water. Qualitative observations reveal that by increasing the velocity ratio, the inner jet spread angle is found to be larger (i.e., the jet spreads faster) and the downstream mixing region is more uniform. Furthermore, local consistency measurements show ...

purpose: to evaluate the effect of vacuum and flow rate on endothelial cell loss after high versus low vacuum phacoemulsification. methods: this randomized clinical trial was performed on 60 eyes of 60 patients with moderate lens opacity (nuclear sclerosis 3+). all surgeries were performed by one experienced surgeon using stop and chop technique with sovereign white star machine (amo). patients...

The atomization of fuel jets in car or plane engines involves complex process with multiphase motions and turbulent flow regimes in a highly coupled way. The Direct Numerical Simulation (DNS) of interfacial flows is investigated in order to characterize the coupling between turbulent flow structures and interface deformations occurring during atomization of a liquid sheet. An incompressible Gho...