A numerical method based on the MacCormack finite difference scheme is presented. The method was developed for simulating two-dimensional overland flow with spatially variable infiltration and microtopography using the hydrodynamic flow equations. The basic MacCormack scheme is enhanced by using the method of fractional steps to simplify application; treating the friction slope, a stiff source ...

When sliding a finger across a bumpy surface, the finger follows the surface geometry (position signal). At the same time the finger is exposed to forces related to the slope of the surface (force signal) [1]. For haptic shape perception the brain uses both signals integrating them by weighted averaging [2]. This is consistent with the Maximum-Likelihood-Estimate (MLE) model on signal integrati...

Geocells are increasingly used in engineering applications, but the design of riverbank slope reinforcements that use only geocells limits reinforcement performance. Moreover, and anti-slide piles with mainly based on experiences unsupported by theoretical models. In this paper, combining confinement effect vertical action mechanism geocells, horizontal friction geocell layer support piles, a m...

To gain a better understanding of the surfaces of planets and small bodies in the solar system, the flow behavior of granular material for various gravity levels is of utmost interest. We performed a set of reduced-gravity measurements to analyze the flow behavior of granular matter with a quasi-2D hourglass under coarse-vacuum conditions and with a tilting avalanche box. We used the Bremen dro...

S. Dippel H ochstleistungsrechenzentrum, Forschungszentrum J ulich, 52425 J ulich, Germany G. G. Batrouni Institut Non-Lin eaire de Nice, Universit e de Nice Sophia-Antipolis, 1361 routes des Lucioles, 06560 Valbonne, France D. E. Wolf Gerhard-Mercator-Universitat, FB 10, 47048 Duisburg, Germany ABSTRACT: Numerical studies of the motion of a ball on a rough incline have shown that the stead...

We study the rheological behavior of concentrated granular suspensions of simple spherical particles. Under controlled stress, the system exhibits an S-shaped flow curve (stress vs shear rate) with a negative slope in between the low-viscosity Newtonian regime and the shear thickened regime. Under controlled shear rate, a discontinuous transition between the two states is observed. Stress visua...

Using backstepping design, exponential stabilization of the linearized Saint-Venant–Exner (SVE) model of water dynamics in a sediment-filled canal with arbitrary values of canal bottom slope, friction, porosity, andwater–sediment interaction, is achieved. The linearized SVEmodel consists of two rightward convecting transport Partial Differential Equations (PDEs) and one leftward convecting tran...

Animals can move in not only elegant but also energy efficient ways. Their skin is one of the key components for this achievement. It provides a proper friction for forward motion and can protect them from slipping on a surface during locomotion. Inspired by this, we applied real shark skin to the foot soles of our hexapod robot AMOS. The material is formed to cover each foot of AMOS. Due to sh...

Friction occurs in all mechanical systems,e.g. bearings, transmissions, hydraulic and pneumatic cylinders, valves, brakes and wheels. Friction appears at the physical interface between two surfaces in contact. Lubricants such as grease or oil are often used but the there may also be a dry contact between the surfaces. Friction is strongly influenced by contaminations. There is a wide range of p...