(cnL + cn−1L + · · ·+ c0I)(x) = 0, for all x ∈ V , cn = 1, cn−1 = −tr (L), · · · c0 = (−1) det(L), c−1 = 0, where I is the identity operator and all ck depend only on L. However, a special form of φ may imply that x also has a specific structure and on this contracted set an m power of L(x) can be expressed through a sum of lower powers with m < n. Consequently, computing the powers of the firs...

A physical-space version of the stretched-vortex subgrid-stress model is presented and applied to large-eddy simulations of incompressible flows. This version estimates the subgrid-kinetic energy required for evaluation of the subgrid-stress tensor using local second-order structure-function information of the resolved velocity field at separations of order the local cell size. A relation betwe...

Despite well-known limitations of Reynolds-averaged Navier–Stokes (RANS) simulations, this methodology remains the most widely used tool for predicting many turbulent flows due to computational efficiency. Machine learning is a promising approach improve accuracy RANS simulations. One major area improvement using machine models represent complex relationship between mean flow field gradients an...

Due to their interesting thermal properties, liquid metals are widely studied for heat transfer applications where large fluxes occur. In the framework of Reynolds-Averaged Navier–Stokes (RANS) approach, Simple Gradient Diffusion Hypothesis (SGDH) and Reynolds Analogy almost universally invoked closure turbulent flux. Even though these assumptions can represent a reasonable compromise in wide r...

The phenomenon of precessing vortex core is observed experimentally when swirl imparted on an axial flow in a pipe. It manifests as coherent structure the form helical regular wavelength whose axis coincident with pipe’s axis. most striking consequence this pattern generation periodic fluctuations streamwise distribution wall static pressure and skin friction. While prediction has proved possib...

In many engineering and industrial applications, the investigation of rotating turbulent flow is of great interest. In rotor-stator cavities, the centrifugal and Coriolis forces have a strong influence on the turbulence by producing a secondary flow in the meridian plane composed of two thin boundary layers along the disks separated by a non-viscous geostrophic core. Most numerical simulations ...

A physical model of gabion overflow dams was studied to determine the velocity profile and Reynolds shear stress. Physical tests were done under two different conditions of dam crest, overflow dams with impermeable and with permeable crests. Instantaneous velocity components over dam crest were measured by an ADV (Acoustic Doppler Velocimeter) instrument. This instrument is capable of measuring...

We synthesize colloidal particles with various anisotropic shapes and track their orientationally resolved Brownian trajectories using confocal microscopy. An analysis of appropriate short-time correlation functions provides direct access to the hydrodynamic friction tensor of the particles revealing nontrivial couplings between the translational and rotational degrees of freedom. The results a...