Learning Forum

[mkalel]

How to turn on the fluid particle interaction? Using transient statenI am doing simulation with nozzle where particle and fluids are coming out from the nozzle throwing in the long cylindrical tube.nBut the problem is at some point the particle stuck in the domain and I feel like the particle is not interacting with the fluid. After stopping the injection at some point, I was assuming the fluid should force the particle further.n can somebody help me ?nthanksn

[YasserSelima]

If you have large circulation in the domain, and your particles' density is higher than the fluid, the particles settle down because of the centrifugal force ... If the particles' density is lower than the fluid, they get stuck in the middle of circulation and they have difficulty going beyond that ... n

[mkalel]

Thank you once again Yasserselima for your helpful comment.nSo do you mean the particle density and fluid density has to be equal to push the particle further by the fluid ? nHere is what I have:nThe particle I am suppose to use for this project is a Deoxidant. which is also called deox powder. The information I have about this powder is:nName of the particle: Deox PowernDensity: 1180 Kg/m^3nCp = 1680 Kg/j/snName of fluid: NitrogennnHere is what I was doing nSo basically I was creating injection from the inlet. I did not found the specific name deox while selecting the the material in the injection. So I was choosing anthracite in the injection.nIn the inert particle option, I was editing the value of density and specific heat of anthracite so that to match with deox powder properties.Ow, I have a inlet from where nitrogen and deox powder is coming at 4m/s.So, what should I do to make the similar density because my particle( deox powder) and nitrogen don't have same density.nor am I doing something wrong by choosing the anthracite and editing its properties?nI have uploaded some of the picture of my injection and fluid selection. can you please help me on this ?nn

[YasserSelima]

I think what you did for the material is right ... just edit one existing material if can't find yours. Also your setting is right, I think .. The issue is the physics ... high density particles will be at the outer edge of circulation, So they land on the wall and get trapped. You can try giving them a density that is close to the fluid and see where they land ... I think they will go much further ... Another trial could be injecting them with low velocity at the pipe centre line and see they just get thrown towards the wall and get trapped to the wall immediately. n

[mkalel]

Thank you for your nice comment. nI liked your idea of trying with the (1) density close to fluid, (2) another with low velocity.nI was using same velocity (4m/s) for both fluid and particle. I would like to perform a trial injecting them with a lower velocity . To inject the particle at the pipe center line, Is there any specific option on the injection dialog box ? or do i have to edit my CAD model of Incoming flow region . I was just using a 1m long cylinder tube as my incoming flow region. nThe upper one is I was using .nnhow about this to make a separate inner tube having a small diameter for the particle injection with in a tube, to inject the particle at the pipe center line?nnnThanks in advancen

[YasserSelima]

I meant actually injection in the centre of the rotating tube. But don't worry about it ... You don't have to change geometry. Create a mass less injection and see how far it goes compared to your particles and to low density particles. nAlso you can increase the injection velocity .. this will make it go further in the hot tube .. n

[Rob]

Have a look at where the particles are going, and finishing up. Assuming the gas flow is sufficient particles will carry through the system, however they can also get caught in recirculation zones and other dead spots. n