An efficient scheme is presented for the numerical calculation of hydrodynamic interactions of many spheres in Stokes flow. The spheres may have various sizes, and are freely moving or arranged in rigid arrays. Both the friction and mobility matrix are found from the solution of a set of coupled equations. The Stokesian dynamics of many spheres and the friction and mobility tensors of polymers ...

For the six-wheel CRAB rover, this paper presents the torque control with Kriging estimation to improve the terrainability by minimizing wheel slip. In previous works, we presented a torque control approach, effectively improving terrainability by minimizing the variance of the required friction coefficient based on the static model. Using a Kalman filter to estimate the velocity information, a...

Long-range hydrodynamics between colloidal particles or fibers is modelled by the fluid particle model. Two methods are considered to impose the fluid boundary conditions at colloidal surfaces. In the first method radial and transverse friction forces between particle and solvent are applied such that the correct friction and torque follows for moving or rotating particles. The force coefficien...

Among the many input parameters of a forging process (for a multi-stage process one can count more than 200 different inputs!) the following important inputs shall be mentioned: Forging Material characteristics (flow curve = f(temperature, strain, strain rate, micro-structure) Influence of heat coefficients Friction type and friction value as well as lubrication Heat transfer Ambient media and ...

The focus of this paper is on adaptive control of maneuvering rigid bodies in the presence of friction. The paper describes a simple technique which include Pulse Amplitude and Pulse Width modulation to progressively move the system to the desired final position. To account for uncertainty in estimated friction coefficients and approximated system model, an adaptation algorithm is necessary to ...

We present a classical rolling contact apparatus where two discs roll and slide under a constant normal loading. Experimental results concerning bearing steel used in ambient air or under severe temperature conditions (Liquid Nitrogen) are presented. A simplified model proposed by Kalker (Fastsim) is used to identify the dynamic friction coefficient between these discs and to study the apparatu...

In this paper, the results of experiments conducted to investigate the friction coefficient existing at a brass-steel interface are presented. The research discussed here is the second of a two-part study on the size effects in friction conditions that exist during microextrusion. In the regime of dimensions of the order of a few hundred microns, these size effects tend to play a significant ro...

The article is devoted to the study of coefficients external friction grain agricultural products-friction in static and dynamic modes, as most important physical mechanical characteristics bulk materials. description carousel laboratory unit, program, methodology results studies on practical determination for typical products according materials working bodies production machines. As a result ...