Determination of the Angle of Repose and Coefficient of Rolling Friction for Wood Pellets

Abstract

The determination of the angle of repose for granular materials is indispensable for their handling and the design of containers and technological processing equipment. On the other hand, computational simulations have become an essential tool to understand the micro-behavior of the granular material and to relate it with the macro-behavior. The experimental determination of the angle of repose has a fundamental role when defining the required parameters to perform realistic simulations. However, there is a lack of a standard that allows the reproducibility of the experiments when using granular materials of equivalent spherical radius greater than 2 mm, such as corn, soybeans, wheat and PLA pellets, among others. In particular, a product of growing importance in the global strategy of decarbonization of the economy is biomass pellets, whose handling operations are one of the main components for the total cost of pellets supplied to the final user. In the present work, with the aim of determining the rolling friction coefficient, the variations in the angle of repose with the drop height for biomass pellets were studied both experimentally and with simulations, and an optimal procedure for its determination was found. Then, a calibration of the coefficient of rolling friction was performed through computational simulations using the discrete element method. The accuracy of the model under different configurations was checked.

Influence of Moisture Content on Some Mechanical Properties of Wheat

“…Classical theories are suitable for determining these loads under static conditions, with the Janssen formula [1] being the world's most widely used. However, numerical methods began to be applied to silo calculations in the 1970s [2], and since then, they have experienced a great surge, especially during the 21st century, thanks to advances in computing [3][4][5][6][7][8][9][10][11][12]. With these techniques, it is possible to accurately predict dynamic loads occurring during both the filling and the emptying of silos, in addition to modeling the static conditions.…”

The Anti-Inflammatory Tablet Formulation of Coleus (Plectranthus Scutellariodes) Leaves Extract Using Kollicoat®protect Coating

“…The measurement of the repose angle was carried out to determine the nature of the adhesion or cohesion of the granules, that would affect the flow properties of the granule. Repose angle of 22.07°, showed the excellent flow property [15,16]. This value showed that granule was effortless to flow and will make uniform shape of tablet core.…”

Calibration and Testing of Parameters for the Discrete Element Simulation of Soil Particles in Paddy Fields

“…(2) The angle of repose test is a widely employed method for calibrating discrete elemental model parameters [20][21][22][23]. Nevertheless, its applicability is constrained when dealing with soils characterized by high water content, primarily due to inherent limitations.…”

“…The angle of repose test is a common method for calibrating model parameters for discrete elements [20][21][22][23]; However, its applicability is limited in soils with high water content. Consequently, the slump test was chosen for its ability to provide a reliable representation of the soil's cohesion, friction properties, and mobility.…”