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How to determine mass flow rate of injections in DPM?

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Old   January 7, 2015, 05:06
Default How to determine mass flow rate of injections in DPM?
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A. N. Huang
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Hello,

I want to inject particles into system from file. I don't know how to determine the value of mass flow rate? What is it definition?

Thank you very much in advance
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Old   January 9, 2015, 10:11
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Hi,
definition of mass flow??
Mass flow has units of kg/s and it is how much material is entering the system per unit of time.
When you use a file for injection(s) you define points of injection(s) (coordinates x,y,z), diameter of particles, injection velocity (vx, vy, vz) temperature of particles and mass flow rate.
If you plan to simulate continuous injection(s) you define the mass flow of particles entering the system for each point you define.
If you are simulating DEM, then you define a stop injection time very small (<simulation time step) and a mass flow such that (mass flow (kg/s)*stop time(s)=mass of one particle (kg).

Daniele
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Old   January 16, 2015, 09:34
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Quote:
Originally Posted by ghost82 View Post
Hi,
definition of mass flow??
Mass flow has units of kg/s and it is how much material is entering the system per unit of time.
When you use a file for injection(s) you define points of injection(s) (coordinates x,y,z), diameter of particles, injection velocity (vx, vy, vz) temperature of particles and mass flow rate.
If you plan to simulate continuous injection(s) you define the mass flow of particles entering the system for each point you define.
If you are simulating DEM, then you define a stop injection time very small (<simulation time step) and a mass flow such that (mass flow (kg/s)*stop time(s)=mass of one particle (kg).

Daniele
Hello,


I simulate a granular system coupled with DEM.

I use this equation (mass flow (kg/s)*stop time(s)=mass of one particle (kg)) to calculate mass flow rate.

Time step is 1e-5.

The k value of Spring-dashopt is 1000, and the eta value of Spring-dashopt is 0.027.

However, the solution still diverge.

Any advice or parameters that may need changed?



Thanks in advance.

anhuang
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