combustion doesn't occur need help plz
 

i am working on 2D combustion chamber i achieved the cold flow and now i am working on combustion i used eddy dissipation model to model combustion but the rate reaction still 0 even with mass fraction of co2 and h2o =0
i use k epsilon for turblent model and group injection for diesel C10h22
my conditions boundary are pressure inlet -oulet
please does anyone have an idea why the combustion doesn't occur with eddy dissipation model

What is your initial temperature? Do you initialize your domain with a high temperature or not?

hi
 

try to run the simulation for various higher temperatures.

re: cpmbustion doesn't occur
 

first of all thank you for replying
i initialize my temperature to 300 k but the temperature in the combustion chamber is about 900 k isn't enough for the combustion of diesel
i even try the patch but nothing that happens

thank's for replying
my initial temperature is about 300 k

No combustion reaction occurs at 300
use higher temp as around 600- 1000 and see the various products

I agree too; use 1000 k and let us know what happens.

response
 

this is the details of my case

•Select k-epsilon model (realizable) under Viscous Model
•Under Species & Transportation I select "Species Transport", Mixture properties "diesel-air" with everything else unchanged.
volumetric : eddy dissipation model
•Now I set up DPM. Enable "interaction with continous phase", enable "unsteady particle tracking", Number of Continous Phase Iterations per DPM Iteration set to 200.
?under Physical Models i enable "DRoplet Collision" and "Droplet Breakup Model". Under Break up constant I set "Breakup Parcel to 50".
?Under Tracking Tab I set Drag Law to "dynamic-drag"
?Particle time step set to 0.00001


•Injections: I create an injection. "group". Particle Type "Droplet". Material "Diesel Liquid". Flow Rate to be 3.22e-4 kg/s. crank angle 700, Stop Time 720.temperature diesel 310k
?Under Turbulent Dispersion I enable "Discrete Random Walk Model" and "Random Eddy Life"
•Under Solve-> Controls -> Solution I leave default settings and select OK
•Now I select Initialize.to 1600k.

when the iteration finished i go to track particle :and i have this summary

Fate Number Elapsed Time (s) Injection, Index
Min Max Avg Std Dev Min Max
---- ------ ---------- ---------- ---------- ---------- -------------------- --------------------
Evaporated 831 3.989e-02 4.000e-02 3.995e-02 0.000e+00 injection-0 0 injection-0 0

(*)- Mass Transfer Summary -(*)

Fate Mass (kg)
Initial Final Change
---- ---------- ---------- ----------
Evaporated 3.434e-08 0.000e+00 -3.434e-08

(*)- Energy Transfer Summary -(*)

Fate Energy (J) Change of Energy (J)
Initial Final Sensible Latent Total
---- ---------- ---------- ---------- ---------- ----------
Evaporated -9.046e-03 0.000e+00 -1.468e-03 1.051e-02 9.046e-03


number tracked = 7297, escaped = 0, aborted = 0, trapped = 0, evaporated = 0, incomplete = 7297, coalesced = 0, shed = 0, splashed = 0
one thing that i don't understand is why the evaporated ones are 0 and the incompleted ones are 7297
still nothing happen

check the arhenius parameters from literature

re
 

thank you for replying
eddy dissipation model doesn't take in account the arhenus chemical reaction are you talking about finte rate / eddy disspiation model ?