Relationship between mass discharge rate and granular temperature of silo flow with variance of outlets

Particuology ◽  
2021 ◽  
Author(s):  
Quan Chen ◽  
Ran Li ◽  
Wengzheng Xiu ◽  
Vladimir Zivkovic ◽  
Hui Yang
2019 ◽  
Vol 14 (1) ◽  
pp. 27-39 ◽  
Author(s):  
Fukashi Maeno ◽  
Setsuya Nakada ◽  
Mitsuhiro Yoshimoto ◽  
Taketo Shimano ◽  
Natsumi Hokanishi ◽  
...  

Kelud Volcano is among the most active volcanoes in Indonesia, with repeated explosive eruptions throughout its history. Here, we reconstructed the relationship between the repose period and the cumulative volume of erupted material over the past 100 years and estimated the long-term magma discharge rate and future eruptive potential and hazards. Tephra data and eruption sequences described in historical documents were used to estimate the volume and mass discharge rate. The volumes of the 1901, 1919, 1951, 1966, 1990, and 2014 eruptions were estimated as 51–296 × 106m3. The mass discharge rates were estimated to be on the order of 107kg/s for the 1919, 1951, and 2014 eruptions and the order of 106kg/s for the 1966 and 1990 eruptions. Based on a linear relationship between the repose period and cumulative erupted mass, the long-term mass discharge rate was estimated as ∼ 1.5 × 1010kg/year, explaining the features of the larger eruptions (1919, 1951, and 2014) but not those of the smaller eruptions (1966 and 1990). This estimate is relatively high compared to other typical basaltic-andesitic subduction-zone volcanoes. This result provides important insights into the evolution of magmatic systems and prediction of future eruptions at Kelud Volcano.


1999 ◽  
Vol 104 (B12) ◽  
pp. 29387-29400 ◽  
Author(s):  
Emily E. Brodsky ◽  
Hiroo Kanamori ◽  
Bradford Sturtevant

2016 ◽  
Vol 121 (8) ◽  
pp. 5679-5695 ◽  
Author(s):  
Gianfranco Vulpiani ◽  
Maurizio Ripepe ◽  
Sebastien Valade

Author(s):  
Conlain Kelly ◽  
Nicholas Olsen ◽  
Dan Negrut

Abstract This study describes the implementation of a granular dynamics solver designed to run on Graphics Processing Units (GPUs). The discussion concentrates on how the Discrete Element Method (DEM) has been mapped onto the GPU architecture, the software design decisions involved in the process, and the optimizations allowed by those decisions. This solver, called Chrono::Granular, has been developed as a standalone library that can interface with other dynamics engines via triangle mesh co-simulation. A scaling analysis of the code presented herein demonstrates linear scaling with problem sizes of over two billion degrees of freedom and closing in on one billion bodies. We conclude with a study of hourglass (or hopper) mass discharge rate which compares the solver to experimental results and investigates a process for determining empirical coefficients of flow rate through simulation.


2006 ◽  
Vol 74 (1) ◽  
pp. 111-118 ◽  
Author(s):  
Hojin Ahn

Rapid granular flow through an orifice (nozzle-shaped flow restrictor) located at the bottom of a vertical tube has been studied using three-dimensional direct computer simulation with the purpose of investigating (1) characteristics of rapid granular flows through the flow restrictor, (2) the choking condition of rapid flow at the orifice and thus conditions at which the maximum discharge rate takes place for the given orifice, and (3) a functional relationship between the discharge rate and flow quantities such as granular temperature and solid fraction. In the present simulation, where the frictional hard-sphere collision operator was employed, it was possible to obtain both rapid and slow (choked) flows through the orifice by controlling the number of particles in the system. The results show that the profile of granular temperature in the vicinity of the orifice plays an important role in determining the choking condition at the orifice. Flow appears to be choked when an adverse granular conduction occurs locally at the orifice in the direction opposite to the mean flow. On the other hand, flow is not choked when the fluctuation energy is conducted in the mean flow direction near the orifice. When flow is not choked, the discharge rate through the orifice increases with increasing solid fraction or normal stress. Once the flow becomes choked, however, the discharge rate decreases as the solid fraction or normal stress increases. Also for inelastic, rough particles, the discharge rate is found to be proportional to the granular temperature to the power of 1.5 and inversely proportional to the gravitational acceleration and the tube length.


2021 ◽  
Vol 377 ◽  
pp. 350-360 ◽  
Author(s):  
Xingjian Huang ◽  
Qijun Zheng ◽  
Aibing Yu ◽  
Wenyi Yan

2017 ◽  
Vol 307 ◽  
pp. 63-72 ◽  
Author(s):  
Q.J. Zheng ◽  
B.S. Xia ◽  
R.H. Pan ◽  
A.B. Yu

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