ABSTRACT: The interface between granular bodies and structures is analysed with the finite element method and a micro-polar hypoplastic constitutive model. Shearing of an infinite long and narrow granular strip between two walls of different roughness under conditions of free dilatancy and constant vertical pressure is investigated. The constitutive model can reproduce the essential features of...

Direct numerical simulations (DNS) of stably-stratified, turbulent plane Couette flow are currently being performed on the XC-4000. The friction Reynolds number is kept approximately constant, Reτ 540 and the Richardson number Riw varies between 0 and 0.1. The flow is divided into two regions: the region close to the wall and the core region. The region close to the wall presents strong velocit...

In the process of research and development of tube bending forming technology, the way of improving the forming quality and establishing the optimization of forming process parameters has become an important problem that should be solved quickly. This text simulated the process of bend forming with the way of finite element, combined with the effects of geometric and physical parameters on the ...

Abstract The convective heat transfer and flow field characteristics through a backward-facing step (BFS) channel combined with corrugated wall is investigated numerically experimentally. Uniform flux applied on 200 mm of the downstream wall, while rest walls are considered isolated surfaces. range Reynolds number (Re) was between 5000 20,000. governing equations were solved using RNG k ? e tur...

Abstract. We discuss the advantages and results of using a mixing-length, compressible model to account for shear banding behaviour in granular flow. We formulate a general approach based on two function of the solid fraction to be determined. Studying the vertical chute flow, we show that shear band thickness is always independent from flowrate in the quasistatic limit, for Coulomb wall bounda...

A new adaptive controller based on a neural network was constructed and applied to turbulent channel flow for drag reduction. A simple control network, which employs blowing and suction at the wall based only on the wall-shear stresses in the spanwise direction, was shown to reduce the skin friction by as much as 20% in direct numerical simulations of a low-Reynolds number turbulent channel flo...

This paper presents a theoretical study on the velocity distribution and the friction factor of boundary layer flows with polymer additives starting from the concept of “stress deficit.” A novel method of order of magnitude analysis is developed, which converts the governing equations of boundary layer flow into a solvable ordinary differential equation, thus the total shear stress distribution...

– Granular materials are known to separate by size under a variety of circumstances. Experiments presented here and elucidated by modeling and MD simulation document a new segregation mechanism, namely segregation by friction. The experiments are carried out by placing steel spheres on a horizontal plane enclosed by rectangular sidewalls, and subjecting them to horizontal shaking. Half the sphe...

The skin friction on a surface is a major concern by engineers. It is widely accepted that turbulent flow has higher friction than laminar flow due to the higher mixing in boundary layer. However, our new high order DNS found that the high friction is generated in a laminar zone in a transitional flow. Whenever the small length scales are generated, the velocity shear becomes very large in the ...

A new quantum-mechanical theory predicts that a neutral liquid can generate an electric current in the solid wall along which it flows. The turn reduces friction at liquid-solid interface.