Granular convection (particle distribution) calculation

In summary, according to the information provided, the four types of particles that will be under turbulent motion are low volume, low density, high volume, low density, and high volume, high density. The particles will be located at the sphere of radius corresponding to their volume and density. The particles will be suspended in air, but will be less likely to be close by.
  • #1
Viky1147
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TL;DR Summary
Need to calculate the distribution of particles in granular convection condition
Hi All,

Am new here came particularly hoping for some guidance

I need to calculate theoretically, how different types of particles (shown below) distribute in a granular convection

Condition:
Large surface or open surface

Types of particles:
1) Low volume, Low density particle
2) High volume, Low density particle
3) Low volume, High density particle
4) High volume, High density particle

How to theoretically calculate particles distribution of the above shown conditions in granular convection. Please guide me.
Thanks.

Regards,
Vivek Rajan
 
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  • #2
Which area of physics is this, Is it Statistical Mechanics perhaps?
 
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  • #3
Ok well, maybe @vanhees71 or @Chestermiller can help I am not very familiar with distributions of particles ...
 
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  • #4
I fear, here I'm not competent. Granular media are a very special and difficult topic. I'm not even aware of textbooks or papers.
 
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  • #5
Delta2 said:
Which area of physics is this, Is it Statistical Mechanics perhaps?
Am not sure of it. I am a mechanical engineer

I am working on a design, in which this granular convection plays a pivotal small role. So thought of documenting a valid theory on it. Did a lot of googling and ended up here hoping to get some guidance :)
 
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  • #6
Welcome to PF.
Maybe start here...
Numerical modelling of granular flows: a reality check. 2015.
C. R. K.Windows-Yule · D. R. Tunuguntla · D. J. Parker
https://www.researchgate.net/profile/Christopher-Windows-Yule/publication/287360347_Numerical_modelling_of_granular_flows_a_reality_check/links/56840a5f08ae051f9af03bbd/Numerical-modelling-of-granular-flows-a-reality-check.pdf?origin=publication_detail
 
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  • #7
Baluncore said:
Welcome to PF.
Maybe start here...
Numerical modelling of granular flows: a reality check. 2015.
C. R. K.Windows-Yule · D. R. Tunuguntla · D. J. Parker
https://www.researchgate.net/profile/Christopher-Windows-Yule/publication/287360347_Numerical_modelling_of_granular_flows_a_reality_check/links/56840a5f08ae051f9af03bbd/Numerical-modelling-of-granular-flows-a-reality-check.pdf?origin=publication_detail
This seems to be far more advance and too complex to understand. Is there any simple and yet proven way so that my case study can be proven.

4 types of particles under turbulent motion, I need to map, where this 4 particles will stand in a map/sketch/some illustration. But, to be proved theoritcally.
 
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  • #8
Viky1147 said:
Is there any simple and yet proven way so that my case study can be proven.
It is a very complex field so we can't guess what you are doing, or in which corner you are operating.
You must reduce the complexity by identifying your case;
1. The purpose of the process.
2. Material(s).
3. Particle size and density spectrum.
4. Size or scale of the equipment. How many tonnes in the heap, flow per hour ?
5. Boundary conditions, wall shape and material and friction.
6. Agitation or motion imparted to the material.
 
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  • #9
Baluncore said:
It is a very complex field so we can't guess what you are doing, or in which corner you are operating.
You must reduce the complexity by identifying your case;
1. The purpose of the process.
2. Material(s).
3. Particle size and density spectrum.
4. Size or scale of the equipment. How many tonnes in the heap, flow per hour ?
5. Boundary conditions, wall shape and material and friction.
6. Agitation or motion imparted to the material.

Types of particles:
1) Low volume, Low density particle
2) High volume, Low density particle
3) Low volume, High density particle
4) High volume, High density particle

These 4 particles, under no/large boundary condition, i need to know where will be the particles located in say after 1 minute of time in turbulent motion.

by assumption i can say high volume high density & low volume high density gets buried under than other 2 particles.

How to prove this theory?
 
  • #10
Viky1147 said:
How to prove this theory?
All particles have either a relatively low volume or a high volume.
All particles have either a relatively low density or a high density.
Stop referring to every particle in the universe and answer the six questions I asked.
You must identify the context if you want to receive help.
 
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  • #11
Baluncore said:
6. Agitation or motion imparted to the material
The OP states "4 types of particles under turbulent motion"". Doesn't that answer this question no.6?
 
  • #12
Baluncore said:
All particles have either a relatively low volume or a high volume.
All particles have either a relatively low density or a high density.
Stop referring to every particle in the universe and answer the six questions I asked.
You must identify the context if you want to receive help.
Yes that's the context itself. These 4 category covers every particles. But,
Under granular convection, where does this 4 particles will be located?
(assuming any volume or density in this 4 categories)
How will we prove that in theory? (considering this parameters alone)
 
  • #13
Delta2 said:
Doesn't that answer this question no.6?
What is the magnitude of the movement relative to particle size ?
What is the separation between the particles ?
What constrains the turbulence, I would expect them to spread across the face of the planet.
Are the particles suspended in air, a liquid ?
There has been no theory presented.
 
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  • #14
Capture.JPG

Weight density:
RED particle 2kg/cm3
Blue particle 1kg/cm3

Volume:
A - Spherical radius - 2cm
B - Spherical radius - 2cm
C - Spherical radius - 1cm
D - Spherical radius - 1cm

amount of particles:
assume equally distributed no. of particles in terms of volume in a large confined space with no other particles.

consider the turbulent motion at maximum velocity of 60 m/s

particles are suspended in surface with no/less friction
 
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  • #15
This software models granular flow in a liquid medium- what it seems you want. But I still am sure that your question is missing more details and you will definitely need them for the model - like actual particle size spectra and material densities for example. Maybe @jrmichler can help.

https://www.flow3d.com/modeling-capabilities/granular-media/
 
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  • #16
@Viky1147
You know it is a complex field, but you still want a simple solution, and you expect that simple solution to be true in any context. I believe that is irrational.

Maybe you should start by writing a set of PDEs for the generalised spectrum of particles that might be present in a generalised fluid. Then the boundary conditions and special cases of your situation can be ignored until you integrate the system.

It appears you want to develop an entire general theory of all particle interactions, something that will delay solution for several years. I would have preferred to minimise the situation being modeled from the start, so I could achieve a functional model this year.

I expect you will later announce an unexpected boundary condition, something you could have specified at the beginning. The entire system will then need to be reformulated. How many times can we expect that to happen over the next 5 years?

Just walk away Baluncore, you don't want to follow this no more.
Note to self: Unwatch this thread.
 
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  • #17
jim mcnamara said:
Maybe @jrmichler can help.
I really appreciate the vote of confidence, but we have an unsolvable problem here:

1) The OP has not, and is apparently unable to, describe the desired end result.
2) The OP has not described the range of boundary conditions.
3) The OP has not described the flow conditions.
4) The OP mentioned "granular convection condition". Convection is a particular type of flow. So what drives the convection?
5) And more...

This person, who wants to "calculate the distribution of particles", cannot even describe the problem they want to calculate. Post #6, by @Baluncore, seems to be a complete answer, but the OP replied six minutes later stating that it was "too complex to understand". The OP wants a simple answer to a complex problem without doing any work.
 
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  • #18
I think the intent of this discussion got misdirected. I didnt intent this as a complex problem.

In granular convection "large particles with low density" seems to push it way up, while high density small particles & high density high particles get buried.

Please correct me if am wrong (this is said to be the basic explanation of granular convection)

Now i want this in a calculation format. This was my intent. I don't want complex solutions for a simple problem.

Thanks,
Viky
 
  • #19
Viky1147 said:
Now i want this in a calculation format. This was my intent. I don't want complex solutions for a simple problem.
What simple problem? So far the feedback you have been getting is that it is not a simple problem. If it is simple, you should be able to come up with a couple equations and use an Excel spreadsheet to work it all out and generate some simple plots, no?

What would you propose as your first try at those Excel spreadsheet equations and the rows and columns of your first simulation?
 
  • #20
berkeman said:
What simple problem? So far the feedback you have been getting is that it is not a simple problem. If it is simple, you should be able to come up with a couple equations and use an Excel spreadsheet to work it all out and generate some simple plots, no?

What would you propose as your first try at those Excel spreadsheet equations and the rows and columns of your first simulation?
As quoted earlier, am not exposed to this field. This is a new theory i need to "understand" for my study, which plays a small pivotal role.

If i would know all the things you have said i would have solved by myself.

My question is this
Capture.JPG

As a mechanical engineer, i can say from the above pic, while shaking the above container,
Case a:
High volume Low density Blue balls tends to raise up

Case b:
High volume high density Golden balls tends to get buried

Am i right here or wrong?
 
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  • #21
i have wasted my time here

everyone in this forum is asking questions (trying to establish themselves as genius by asking questions)

all these without even understanding the intent of the question

SIMPLE QUESTIONS NEEDS SIMPLE ANSWERS! NOT A COMPLEX ANSWER!

ADIOS TO THIS FORUM AND ALL THE GENIUS!
 
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  • #22
Vaya con Dios.
 
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FAQ: Granular convection (particle distribution) calculation

1. What is granular convection and why is it important?

Granular convection is the process of particles moving and mixing within a granular material due to differences in density. This phenomenon is important because it can affect the behavior and properties of granular materials, such as in industrial processes or natural systems.

2. How is granular convection calculated?

Granular convection can be calculated using mathematical models that take into account factors such as particle size, shape, and density, as well as external forces like gravity. These models can be solved through numerical simulations or analytical methods.

3. What are the main challenges in calculating granular convection?

One of the main challenges in calculating granular convection is the complexity of the interactions between particles. These interactions can be difficult to model accurately, and can also vary depending on the type of granular material. Additionally, the large number of particles involved in granular systems can make calculations computationally intensive.

4. How does granular convection differ from fluid convection?

Granular convection differs from fluid convection in several ways. In granular convection, the particles do not flow continuously like a fluid, but rather move in bursts or avalanches. Additionally, the behavior of granular materials can change depending on the level of stress or force applied, while fluid convection is largely unaffected by external forces.

5. How is granular convection used in practical applications?

Granular convection has many practical applications, such as in the pharmaceutical industry for mixing powders, in geology for understanding sediment transport, and in agriculture for designing grain storage facilities. It is also being studied for potential uses in energy storage and transportation systems.

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