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Siva April 9, 2004 04:57

Droplet evaporation
Hai i am doing the discrete phase model injection in a carburetor model.The droplet is injected into the air stream. In actual case these droplets will vapourise when it is moving in the airstream. In my case i am able to see the droplet trajectory but i am not able to see the vapourisation of droplet. Can anybody knows how to implement vapourisation effect in the DPM model? Which parameter is used to define the vapourisation in DPM model?

AMV April 9, 2004 08:16

same here
Hi Siva,

I am facing exactly the same problem.

Actually I came to this site to present this very problem.

I am injecting gasoline spray in ic engine combustin chamber. The vaporization is supposed to happen if (a) the concentration at droplet surface > conc of fuel in ambient and (b) the droplet temp > Vaporization temperature

In my case, both these things are present but still no vaporization.

But I could get results for steady case on fixed grid earlier from the spray model but in this case of ic engine spray, the mesh is not fixed its deforming and also the case is transient not steady

I am getting only droplet heating but not vaporization.

Anybody else knows the answer please ??

Siva April 9, 2004 11:12

Re: Droplet evaporation
Hai AMV! Thanks for ur message. u mean to say that with fixed grid and steady state we can see the evaporation.

David April 9, 2004 15:51

Re: same here

to get evaporation you need to patch a high temperature to a zone so that the droplet can evaporate. You need to mark the region through adapt-> mark and define the coordinates of the region you want to mark. Then under solve -> initialize -> patch, choose the zone defined through mark and implement a high temperature (preferably high than evaporation temperature) and that would create the ignition.

It would be used only as an initial condition, then the evaporation would normally sustain itself by the combustion process.

I hope this helps


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