Multi-scale modelling of segregating granular flows
Event details
| Date | 26.11.2015 |
| Hour | 12:15 › 13:00 |
| Speaker |
Prof. Anthony Thornton, University of Twente Bio: Anthony Thornton works jointly between the Multi-scale Mechanics (MSM) and Mathematics of Computational Science (MaCS) groups. His main research interest is in granular materials, primarily size segregation in dense granular avalanche flows. During this research a continuum model of size segregation for dense granular free surface flows was developed and compared to simple laboratory experiments. Current research focus is now on using this model and particle simulation methods to explain phenomena caused by segregation. These include pattern formation in rotation drums, levee formation in geophysical flows, particle size structure of a flowing finite mass of material in avalanches and axial segregation in long rotating cylinders. |
| Location | |
| Category | Conferences - Seminars |
From inclined planes to drums; via a volcano
Many flows in the natural environment or industry consist of shallow rapidly moving segregating granular flows (e.g. from snow avalanches, landslides, debris flows, pyroclastic flows to flows in rotating drum mixers, kilns and crushers). It is important to know the degree of segregation in such flows as it is vital to predict the flow dynamics accurately.
Continuum methods are able to simulate the bulk behaviour of such flows, but have to make averaging approximations reducing the degree of freedom of a huge number of particles to a handful of averaged parameters. Once these averaged parameters have been tuned via experimental, simulational or historical data, these models can be surprisingly accurate; but, a model tuned for one flow configuration often has no predictive capability for another setup.
On the other hand discrete particle methods are a very powerful computational tool that allow the simulation of individual particles by solving Newton's laws of motion for each particle. With the recent increase in computational power it is now possible to simulate flows containing a few million particles; however, for 1mm particles this would represent a flow of approximately 1 litre, which is many orders of magnitude smaller than the flow volumes found in industry or nature.
This talk will focus on a simplified example of bi-dispersed dry granular flows (varying in size and density) on inclined planes and in rotating drums. We will investigate this problem via the continuum modelling approach (both numerical and analytical solutions will be presented) and particle simulations, and conclude by discussing how both can be combined to reveal deeper insight.
Many flows in the natural environment or industry consist of shallow rapidly moving segregating granular flows (e.g. from snow avalanches, landslides, debris flows, pyroclastic flows to flows in rotating drum mixers, kilns and crushers). It is important to know the degree of segregation in such flows as it is vital to predict the flow dynamics accurately.
Continuum methods are able to simulate the bulk behaviour of such flows, but have to make averaging approximations reducing the degree of freedom of a huge number of particles to a handful of averaged parameters. Once these averaged parameters have been tuned via experimental, simulational or historical data, these models can be surprisingly accurate; but, a model tuned for one flow configuration often has no predictive capability for another setup.
On the other hand discrete particle methods are a very powerful computational tool that allow the simulation of individual particles by solving Newton's laws of motion for each particle. With the recent increase in computational power it is now possible to simulate flows containing a few million particles; however, for 1mm particles this would represent a flow of approximately 1 litre, which is many orders of magnitude smaller than the flow volumes found in industry or nature.
This talk will focus on a simplified example of bi-dispersed dry granular flows (varying in size and density) on inclined planes and in rotating drums. We will investigate this problem via the continuum modelling approach (both numerical and analytical solutions will be presented) and particle simulations, and conclude by discussing how both can be combined to reveal deeper insight.
Practical information
- Informed public
- Free
Organizer
- Christophe Ancey (ENAC/IIC/LHE)
Contact
- Christophe Ancey (ENAC/IIC/LHE)