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-   -   use dpm to simulate diesel spray (http://www.cfd-online.com/Forums/fluent/64665-use-dpm-simulate-diesel-spray.html)

lzh1056 May 19, 2009 09:36

use dpm to simulate diesel spray
 
Hi

I am now using FLUENT to simulate the diesel spray process without combustion in a constant volume. I use the plain orifice atomizer and activate the WAVE breakup model and droplet collision model. I am doublt the results show that the sauter mean diameter is always increasing with the time going on. It seems that the droplets don't breakup but coalesce. I don't know why,could anyone help me? Is the solid cone type injection more suitable for diesel spray? Thnaks.

prasad.ichal May 20, 2009 06:26

Hi,

How about the air surrounding the nozzle? Is it swirling? Have you used correct model constants?

Best regards
Prasad

lzh1056 May 21, 2009 02:02

Quote:

Originally Posted by prasad.ichal (Post 216704)
Hi,

How about the air surrounding the nozzle? Is it swirling? Have you used correct model constants?

Best regards
Prasad

Hi,Prasad
The fuel is injected to quiescent air so there is no swirl.
I also try to change the value of B1 from 1.73 to 60 in the
WAVE model. However the sauter mean diameter increase with
time going on at each value of B1. I am now confused.

Best regards

prasad.ichal May 28, 2009 07:32

You will have to set sheet constant and ligament constant in the injection. I believe only some experimental data can lead you to arrive at the combination of constants.


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