Hi every one
I want to use CFD-DEM for my simulation, but I donot have enough information about my solids, like spring constant . how can I determine this information?
Start with the default value of 1,000 N/m. The spring constant is not a physical property, and we use an artificially low value to get acceptable time step. If the default value is too low (too soft particles will go through walls), increase the value, say by a factor of 10.
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thanks for your replying
as I understand, chang the spring constant have an affect on minimum fluidization velocity. how can I measure or determine the best one?
The real spring constant should be much larger than 1000, it is just a model parameter in the soft sphere DEM. You need to do some model calibrations as there are many parameters will affect the flow hydrodynamics, such as collision coefficient, friction coefficient, drag model besides the spring constant. I usually set the spring constant between 200-1000 N/m. A sensitivity study may be needed to best match the experimental data.
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