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December 27, 2010, 16:28 |
Gidaspow model
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#1 |
Member
sara
Join Date: Sep 2010
Posts: 33
Rep Power: 16 |
hi
i am modeling a domain with 2 phases. one phase is water and other phase is dispersed solid. i selected Gidaspow for drag coefficient but it doesn't run and one error occur. when i select Schiller Naumann, program run but its results is incorrect. do you know that why this model don't run with Gidaspow model? |
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December 27, 2010, 17:34 |
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#2 |
New Member
pannsave
Join Date: Apr 2009
Posts: 25
Rep Power: 17 |
Could you specify the more details of your problem,
What is the solid volume fraction and mean particle size in your case What was the error .. |
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December 27, 2010, 17:46 |
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#3 |
Member
sara
Join Date: Sep 2010
Posts: 33
Rep Power: 16 |
yes, of course. volume fraction of sand is 0.73 and mean particle size is 1.28 mm. i selected these options in domain:
maximum packing=0.62 restitution coeff= 0.8 fluid models= inhomogeneous for particles: kinetic theory is on. granular temperature model= algebraic radial distribution = Gidaspow turbulence= laminar solid bulk viscosity,shear viscosity and pressure model= kinetic theory drag coefficient= Gidaspow program don't run and no result file error is shown. do i define other option for remove this error and run it? do i define minimum volume fraction for it? |
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December 27, 2010, 19:41 |
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#4 |
New Member
pannsave
Join Date: Apr 2009
Posts: 25
Rep Power: 17 |
Could you check whether your simulation run without an error when kinetic theory model is off and use simple model of gidaspow for solid pressure.
May be problem with the prediction of granular temperature value and check it Sometimes they may have unphysically large granular temperatures where the regions of low solid particle volume fraction. so in order prevent this, specify an upper bound for the granular temperature |
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December 28, 2010, 01:20 |
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#5 |
Member
sara
Join Date: Sep 2010
Posts: 33
Rep Power: 16 |
thank you very much for attention you. yes, i has run it without kinetic theory but results are incorrect.
how i can specify an upper bound for the granular temperature? |
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December 28, 2010, 04:37 |
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#6 |
New Member
pannsave
Join Date: Apr 2009
Posts: 25
Rep Power: 17 |
There is option for specifying upper bound of granular temperature in Kinetic theory model ie., Maximum granular temperature option
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December 28, 2010, 07:43 |
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#7 |
Member
sara
Join Date: Sep 2010
Posts: 33
Rep Power: 16 |
what is the value of it? i don't find its value.
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December 28, 2010, 11:26 |
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#8 |
New Member
pannsave
Join Date: Apr 2009
Posts: 25
Rep Power: 17 |
I dont know extactly the range of maximum granular temperature, May be you can look it in the literature
I prefered to give in the range of 0.01 m2/s2 Orlese you try different values to ensure the simulation results are independent of maximum granular temperature |
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January 1, 2011, 07:30 |
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#9 |
Member
sara
Join Date: Sep 2010
Posts: 33
Rep Power: 16 |
hi
In this model, i turned off kinetic theory, and used Gidaspow model with compact modulus = 100 for solid pressure. Is this model suitable for modeling Water and sediment? i modeled it inhomogeneous, is it correct or i should model it homogeneous? |
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