[JoshS.]

Hi,

I want to ask how do I calculate the injection rate in the spray module if i know the amount I wanna inject and also the injection pressure?

Say i need to inject 2mg of diesel at a injection pressure of 40MPa what would be the injection rate?

[kimmhw]

Hi JoshS,

There is no special way to get the appropriate injection rate.
Injection rate should be a result from many factors.
- whole FIE system, injector mechanism, injection pressure, duration, nozzle shape, environment condition..

Normally, this is measured in special device or simulated with FIE simulation tool like as HYDSIM or AMESIM.

Otherwise, you may take a injection rate diagram from paper/reference with similar injector/condition.

[JoshS.]

Hi, kimmhw

In fire, the mass in computational domain under injected mass, why does it not equal to the total mass injected? and is there any place I can set the injection pressure?

[kimmhw]

Hi, JoshS,

There is no input area for injection pressure.
As I told, the injection pressure is not an input in case of 3D spray/combustion simulation.

Regarding the difference between target mass and actual injected mass, I have no idea.
It should be same after end of injection.

[Rouzbehnejatbakhsh]

I have some problems in modelling sprays in part load in internal combustion engines
if possible for any one help me about this issue I work in AVL FIRE buti dont know which parameters i should change in sub model please help me

[kimmhw]

Hi rouzbehnejatbakhsh,

You should describe your problem in detail.
Gasoline?Diesel?
Operating point
Which breakup model / combustion model is used?
How different between FIRE and measurement?
Others.

Actually, there are so many factors which affect to simulation results.

[Rouzbehnejatbakhsh]

Originally Posted by kimmhw

Hi rouzbehnejatbakhsh,

You should describe your problem in detail.
Gasoline?Diesel?
Operating point
Which breakup model / combustion model is used?
How different between FIRE and measurement?
Others.

Actually, there are so many factors which affect to simulation results.

Thanks
the main topic is this:
numerical study on the hydro dynamics behavior os fuel spray in part load operating conditions
by part load we mean 2500 to 3500 rpm
and we prefer diesel
we dont consider combustin and just the specifictions of spray are importent for me
Iuntil now I cant finf any expermental article on this topic if it is possible for you help me more!

[Rouzbehnejatbakhsh]

Originally Posted by kimmhw

Hi rouzbehnejatbakhsh,

You should describe your problem in detail.
Gasoline?Diesel?
Operating point
Which breakup model / combustion model is used?
How different between FIRE and measurement?
Others.

Actually, there are so many factors which affect to simulation results.

And I have some other questions too what is the diffrence between full and part load conditions which parametrs i should vary and change for compration of these modes?
and some information about fuel injectors too!thanks!

[kimmhw]

Hi Rouzbehnejatbakhsh,

Frankly, I cannot understand what you mentioned "numerical study on the hydrodynamics behavior of fuel spray"

Regarding part/full load condition, well.. air mass, wall temp., injected mass/timing/rate will be changed.

If you have no previous experiences, please start with primer and example.

[Rouzbehnejatbakhsh]

Originally Posted by kimmhw

Hi Rouzbehnejatbakhsh,

Frankly, I cannot understand what you mentioned "numerical study on the hydrodynamics behavior of fuel spray"

Regarding part/full load condition, well.. air mass, wall temp., injected mass/timing/rate will be changed.

If you have no previous experiences, please start with primer and example.

Hi
I mean by hydrodynamic that the behavior of spray without considerations of combustion and just the cfd modeling of spray and the SMD and PENTRATION AND OTHER spray important specification in AVL FIRE SOFTWARE
PLEASE HELP ME MORE ON THIS ISSUE

[sina1600]

hi , how can i import Injection Rate Diagram ?

[rdrd4u]

u can import in the form of table...i.e.
crank angle vs quantity to be injected..