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Actually no, I didn't use PBM yet. I want to learn the concept of this model I appreciate if anyone knows a reference. |
invalid data on PBM
Hi
I am modeling two phase(water-in-oil) multiphase in a tank with Rushton impeller and I face a problem in aggregation and breakage system of my PBM. the problem is that I use discrete method for population balance and I have 7 bins. the bin fractions are not correct. (bin0=.99 and other bins are totally 0.01) I should mention that bin0 is the bin with largest droplet diameter. it seems that breakage doesn't happen in my tank. even I just use breakage without coalescence I saw no change in droplet diameter. any help will be appreciated:) |
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Bins 7 Ratio 1.3 Let asume Min size 0.1 cm ( better to use experimental value ) then set like this: Fraction Bin-0 0 Bin-1 0 Bin-2 0 Bin-3 1 ( The mean particle size 0.25cm will the middle one ) Bin-4 0 Bin-5 0 Bin-6 0 Good Luck |
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thank dude, I model experimental data from another guy... the particle size varies between 50micrometer to 280 micrometer so I use this size in population balance and ratio equal to one. I patch the volume fraction and I patch bin fractions as follows: bin0,1,3,4,5,6=0.1 bin2=0.4 because the sauter mean diameter is in this range. |
please help me
hello everyone
do any one explain the formation of crystal step by step? secondary phase is my crystal phase and i put the volume fraction zero in boundary condition. i dont have any computation for secondary phase so this mean that crystal phase is not formatting. why crystal phase dont form?? could you please help me? |
using file for size distribution in PBM model
Hey guys,
Do you know how we could specify size distribution for PBM model by using a file in ANSYS FLUENT? Thanks in Advance, |
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You need to assign the number of bins before loading the file. The diameters should be ascending, and only one diameter per line! This is the content of a sample file that I used while ago: Code:
0.0000015 |
Changing discrete method to inhomogeneous method in PBM model
Hi everyone
I'm simulating a rectangular duct with velocity inlet and pressure outlet in order to see how water and air (that had been injected from an inlet with each other) separate from each other. I have used the discrete method with 8 bin fractions for solving the population balance equation. Now I wanna change my method to inhomogeneous and continue the simulation. After adding another phase and defining bin fractions in the third phase, I encounter an error: ================================================== ============================ Node 0: Process 568: Received signal SIGSEGV. ================================================== ============================ ================================================== ============================ Node 1: Process 4360: Received signal SIGSEGV. ================================================== ============================ ================================================== ============================ Node 2: Process 1952: Received signal SIGSEGV. ================================================== ============================ ================================================== ============================ Node 3: Process 3732: Received signal SIGSEGV. ================================================== ============================ ================================================== ============================ Node 4: Process 4904: Received signal SIGSEGV. ================================================== ============================ ================================================== ============================ Node 5: Process 1448: Received signal SIGSEGV. ================================================== ============================ ================================================== ============================ Node 6: Process 3892: Received signal SIGSEGV. ================================================== ============================ MPI Application rank 0 exited before MPI_Finalize() with status 2 The fl process could not be started. I would be absolutely grateful for your responses... |
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And I also encountered another problem with the Inhomogeneous method of PBM in AnsysFLUENT. Do we need special treatment other than enabling aggregation phenomena to make bubbles in a smaller velocity group to go to a bigger velocity group?? I cannot see a transition between velocity groups in my simulations. For instance, when I inject a swarm of bubbles, their diameter would increase till reaching the maximum diameter of their own velocity group and do not go to a bigger velocity group although I have some bigger velocity groups in my problem. Does anyone have some advice...? Thanks in advance |
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Hello All!
I am using the Inhomogeneous discrete method in AnsysFluent PBM model. I have two phases and I want to define just one bin for each phase...after setting this condition, phrase "-1.#IND" will be showed in Ratio Exponent and Max Diameter box:confused: (as shown in the picture) Do you know what it means...and is it an error?? Thanks in Advance...:) |
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Actually I want to find aggregation kernel using experimental data to link with FLUENT but I am not sure how to do this. Can you please help me in this case. I appreciate your assist. Regards. |
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PBM is actually Bullshit and headache but it used alot in industry. If you want I have pdf books and ANSYS documents I can share with you. email me on e.zhaleh@gmail.com. |
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Do you mean that you wanna develeop a kernel? Like lou and other researchers? Please explain more... |
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Good Luck, Masoud Ravan |
Hi all,
I'm trying to simulate CO2 bubble cavitation in water with dissolved CO2 flowing in a venturi tube. Is using this model in the right direction? If anyone can guide me through just a starting point with using this model, that'd be great. What should the From and To Phase be under mass transfer? Is using species appropriate? Regards. |
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