A nonlinear model for biological and physical dynamical interactions in a laminar flow field being upwelled into the mixed layer Robinson(1999) (Fig 1, below) has been extended to turbulent flow (Goodman and Robinson, 2007). The approach of the Goodman and Robinson theory has been to develop a probability density function (pdf) for the turbulent displacement field and use that to calculate the ...

Turbulent flows near walls have been the focus of intense study since their first description by Ludwig Prandtl over 100 years ago. They are critical in determining the drag and lift of an aircraft wing for example. Key challenges are to understand the physical mechanisms causing the transition from smooth, laminar flow to turbulent flow and how the turbulence is then maintained. Recent direct ...

The article presents the analysis of the processes occurring together with the turbulent transfer of impulse in mixture of hydrocarbon fluid and polymer solutions (antiturbulent additives). The study evaluates complex shear flows by popular theoretical and practical methods. Understanding of hydrodynamic and dissipative effects of laminar-turbulent transition tightening and turbulence suppressi...

We present simulation results of flows in the finite Knudsen range, which is in the slip and transition flow regime. Our implementations are based on the Lattice Boltzmann method and are accomplished within the Peano framework. We validate our code by solving twoand three-dimensional channel flow problems and compare our results with respective experiments from other research groups. We further...

Improvements in micro-fabrication techniques are enabling Micro-Electro-Mechanical-Systems to be constructed with sub-micron feature sizes. At this scale, even at standard atmospheric conditions, the flow is in the transition regime. This paper considers the range 0.1 < Kn < 1, where non-equilibrium effects can be appreciable, and specifically illustrates problems involving non-planar surfaces ...

By X I A O H U A W U , R O B E R T G. J A C O B S , J U L I A N C. R. H U N T 2 AND P A U L A. D U R B I N 1 Center for Integrated Turbulence Simulations, Flow Physics and Computation Division, Department of Mechanical Engineering, Stanford University, Building 500, Stanford, CA 94305-3030, USA e-mail: [email protected]; [email protected]; [email protected] Department of App...

A chute is characterized by a steep bed slope associated with torrential flow. This chute flow may be either smooth or stepped. The flow conditions in stepped channels are classified as nappe flow, transition flow and skimming flow. In this paper, hydraulic characteristics of flow regimes on the stepped channels are presented systematically under a wide range of discharge, channel slope and ste...

The Shortfin Mako shark (Isurus oxyrinchus) is a fast swimmer and has incredible turning agility, and has flexible scales known to bristle up to 50° in the flank regions. It is purported that this bristling capability of the scales may result in a unique pass flow control method to control flow separation and reduce drag. It appears that the scales have evolved to be only actuated when the flow...

One-way coupled Euler-Lagrangian simulations of bubbles in a spatially evolving turbulent boundary layer were performed. The simulation parameters were chosen to match an experiment by Sanders et al. (2006), though the Reynolds number of the boundary layer was lower than experiment. The bubbles were observed to migrate away from the wall, as observed in experiment. Budgets of the forces on the ...