In the computational fluid dynamics (CFD) modeling of gas-solids two phase flow, the effect of boundary conditions play an important role in predicting the hydrodynamic characteristics of fluidized beds. In this work, the hydrodynamics of conical fluidized bed containing dried TiO2 nano-agglomerates were studied both experimentally and computationally. The pressure drop ...

The paper discusses a sliding mode control suitable for compensation of nonlinear microdynamic friction and parameter changes in a ball-screw driven slide system. The conventional, fixed-gain sliding mode control has a limited range of performance in the presence of varying nonlinear friction in submicrometer trajectory tracking. In this work, an algorithm that effectively calculates variable s...

The motion of an elastic body over a rough surface is simulated in one dimension using Newtonian dynamics. We drive the body by prescribing a constant velocity. We extract the friction force from the work done by the applied force in order to maintain the motion of the body. A positive amount of work is needed because energy is converted into the internal elastic degrees of freedom of the body....

This article describes the detailed friction modeling of the Genera1 Electric GP132 industrial robot. Friction is an area whose importance is often discounted in the development of control systems because it is thought to be insignificant or unmodelable. This work demonstrates that friction does have a predictable structure, and that significant performance improvement can be realized through i...

Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as ye...

This work presents a nonlinear control algorithm to be applied to the trajectory tracking of a pneumatic positioning system. The objective is to compensate the highly nonlinear effects that are inherent to such systems due to the dynamic behavior of pressurized air inside the chambers and to friction forces. In order to accomplish this task, the proposed algorithm employs the feedback lineariza...

agricultural crops and food materials exert frictional forces on agricultural machinery elements and on storage walls during their harvest, transportation, processing and storage. coefficient of friction is an important parameter to be predetermined in designing equipments and evaluating processes. an assessment of the coefficient of friction for agricultural materials is usually done through s...

Friction is the result of complex interactions between contacting surfaces in a nanoscale perspective. Depending on the application, the di erent models available are more or less suitable. Available static friction models are typically considered to be dependent only on relative speed of interacting surfaces. However, it is known that friction can be a ected by other factors than speed. In thi...

Finite Element Analysis (FEA) based techniques have become increasingly available to simulate metal cutting process and offer several advantages including prediction of tool forces, distribution of stresses and temperatures, estimation of tool wear, optimization of cutting conditions, tool edge geometry and coatings, and determination of residual stresses on machined surfaces. However, accuracy...

We develop two new continuum contact models for coupled adhesion and friction, and discuss them in the context of existing models proposed in the literature. Our new models are able to describe sliding friction even under tensile normal forces, which seems reasonable for certain adhesion mechanisms. In contrast, existing continuum models for combined adhesion and friction typically include slid...