On the continuum modeling of dense granular flow in high shear granulation

2014 ◽  
Vol 268 ◽  
pp. 339-346 ◽  
Author(s):  
P.J. Abrahamsson ◽  
S. Sasic ◽  
A. Rasmuson
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ákos Sudár ◽  
Gergely Futaki ◽  
Róbert Kovács

Abstract The thermal modeling of biological systems is increasingly important in the development of more advanced and more precise techniques such as ultrasound surgery. One of the primary barriers is the complexity of biological materials: the geometrical, structural, and material properties vary in a wide range. In the present paper, we focus on the continuum modeling of heterogeneous materials of biological origin. There are numerous examples in the literature for non-Fourier thermal models. However, as we realized, they are associated with a few common misconceptions. Therefore, we first aim to clarify the basic concepts of non-Fourier thermal models. These concepts are demonstrated by revisiting two experiments from the literature in which the Cattaneo–Vernotte and the dual phase lag models are utilized. Our investigation revealed that these non-Fourier models are based on misinterpretations of the measured data, and the seeming deviation from Fourier’s law originates from the source terms and boundary conditions.


Author(s):  
Alessandro Tasora ◽  
Mihai Anitescu

Aiming at the simulation of dense granular flows, we propose and test a numerical method based on successive convex complementarity problems. This approach originates from a multibody description of the granular flow: all the particles are simulated as rigid bodies with arbitrary shapes and frictional contacts. Unlike the discrete element method (DEM), the proposed approach does not require small integration time steps typical of stiff particle interaction; this fact, together with the development of optimized algorithms that can run also on parallel computing architectures, allows an efficient application of the proposed methodology to granular flows with a large number of particles. We present an application to the analysis of the refueling flow in pebble-bed nuclear reactors. Extensive validation of our method against both DEM and physical experiments results indicates that essential collective characteristics of dense granular flow are accurately predicted.


2012 ◽  
Vol 220 ◽  
pp. 7-14 ◽  
Author(s):  
V. Vidyapati ◽  
M. Kheiripour Langroudi ◽  
J. Sun ◽  
S. Sundaresan ◽  
G.I. Tardos ◽  
...  

1968 ◽  
Vol 90 (3) ◽  
pp. 549-552
Author(s):  
F. W. Smith

A general basis for discussing nonlinearity in the flow of molecular fluids consists in applying the continuum mechanics of Coleman and Noll to a flow process governed by an Arrhenius activation energy equation. The theory predicts the familiar exponential increase of viscosity with pressure and a decrease in viscosity with high shear stress, and also predicts the existence of “normal stresses” under high shear stress. Schematic calculations are presented for the behavior of a lubricant under extreme stress.


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