Abstract
The dynamics of rapid granular flows is governed by dissipative
interactions of particles with each other and with the system walls. To adequately describe these interactions, roughness and particle shape must be
taken into account. The coefficient of restitution for arbitrary particles thus
depends not only on material properties and impact velocity but also on the
angular orientation at the instant of the collision. By measurements of the
coefficient of restitution from the sound signal emitted by a sphere bouncing
repeatedly off the ground, it was found that small deviations from the perfect shape of the sphere lead to large measurement errors. Using stochastic
methods, the effective coefficient of restitution for the collision of a rough
sphere with a plane was described as a fluctuating quantity, characterized by
a rather uncommon probability density function. It was shown that modelling
the coefficient of restitution as a stochastic variable significantly affects the
dynamics of particles under rapid granular flows. The decay of temperature
of rapid granular flows in the homogeneous cooling state deviates from Haff’s law for gases of particles interacting via a constant coefficient of restitution
also from the scaling law for gases of viscoelastic particles.
interactions of particles with each other and with the system walls. To adequately describe these interactions, roughness and particle shape must be
taken into account. The coefficient of restitution for arbitrary particles thus
depends not only on material properties and impact velocity but also on the
angular orientation at the instant of the collision. By measurements of the
coefficient of restitution from the sound signal emitted by a sphere bouncing
repeatedly off the ground, it was found that small deviations from the perfect shape of the sphere lead to large measurement errors. Using stochastic
methods, the effective coefficient of restitution for the collision of a rough
sphere with a plane was described as a fluctuating quantity, characterized by
a rather uncommon probability density function. It was shown that modelling
the coefficient of restitution as a stochastic variable significantly affects the
dynamics of particles under rapid granular flows. The decay of temperature
of rapid granular flows in the homogeneous cooling state deviates from Haff’s law for gases of particles interacting via a constant coefficient of restitution
also from the scaling law for gases of viscoelastic particles.
Original language | English |
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Title of host publication | Particles in Contact |
Subtitle of host publication | Micro Mechanics, Micro Process Dynamics and Particle Collective |
Editors | Sergiy Antonyuk |
Publisher | Springer |
ISBN (Electronic) | 978-3-030-15899-6 |
ISBN (Print) | 978-3-030-15898-9 |
Publication status | Published - 2019 |