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-   -   No steep rise in pressure curve (https://www.cfd-online.com/Forums/star-cd/150161-no-steep-rise-pressure-curve.html)

srivathsanpoyyapakkam March 16, 2015 22:34

No steep rise in pressure curve
 
I am currently simulating HCCI Mode of Combustion with n - heptane as the fuel. My problem is that I am unable to get a steep rise in the pressure curve although I have a considerable amount of heat release (perceived from the spd file) I have given the following parameters as the input

1. combustion model - ECFM-3Z
2. Cetane no - 60
3. Eq ratio - 0.29
4. EGR - 0%
5. Initial Pressure - 6.14 bar
6. Initial Temp - 503K
7. Injected Mass - 4.716e-4 kg/s (pls tell me whether this mass is sufficient for combustion or not)


Should I need to change any of the ignition parameters?

cnaksoy March 19, 2015 02:42

Hi,
Firstly, what is your injector hole diameter? You should write its diameter values as meter (m) in Pro-Star.
And I guess eq ratio should be bigger, for example 0.85. I usually use Lambda value for air/fuel mixture.(Lambda = 1.5-1.8 for diesel engines).
I am not sure about the mass of injected fuel. Maybe you should check it by using 1D simulation.

Quote:

Originally Posted by srivathsanpoyyapakkam (Post 536651)
I am currently simulating HCCI Mode of Combustion with n - heptane as the fuel. My problem is that I am unable to get a steep rise in the pressure curve although I have a considerable amount of heat release (perceived from the spd file) I have given the following parameters as the input

1. combustion model - ECFM-3Z
2. Cetane no - 60
3. Eq ratio - 0.29
4. EGR - 0%
5. Initial Pressure - 6.14 bar
6. Initial Temp - 503K
7. Injected Mass - 4.716e-4 kg/s (pls tell me whether this mass is sufficient for combustion or not)


Should I need to change any of the ignition parameters?


srivathsanpoyyapakkam March 19, 2015 03:05

Hi,

Thanks for the reply. My injector hole diameter is 0.188mm. I have found out that my injection mass was not sufficient for combustion.

Can you please help me in deciding the ignition model ?

cnaksoy March 19, 2015 03:44

I will try. what do you need?

Quote:

Originally Posted by srivathsanpoyyapakkam (Post 537110)
Hi,

Thanks for the reply. My injector hole diameter is 0.188mm. I have found out that my injection mass was not sufficient for combustion.

Can you please help me in deciding the ignition model ?



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