AVL FIRE Engine combustion convergence problem
 

Dear All Members,

Iam using latest AVL fire 2010 (v9.1) version for simulating engine combustion. Detaiked combustion chamber meshing was done using inbuilt moving mesh tool ,. I get SOLUTION DIVERGED message just after few iterations.
Th following are the inputs
1 . k-zeta-f and turbulent flame speed closure model and spark ignition model
2. Initial Turbulent kinetic enrgy and length scale based on the actual values

I reduced time step to 10e-6 , changed differencing scheme to upwind,reduced under relaxation factors but still getting same message.

moving meshing was created using inbuilt Fame engine plus tool, at the end of meshing process i get a message that the mesh can be used for calculation .
I tried to use a mesh of a simple geometry without crevices n liners, it works well n i get the result as well.
Please help me :(

Thanks in advance

Regards
Vikram

Hi...i am just trying to understand the pros of AVL fire though am familiar with AVL Boost...
can any1 throw some light on AVL fire? so that i can link the boost engine combustion models in AVL fire or what not... what stuff AVL Fire can do where Boost cant|????

well the case should be examined carefully, but I think there might be some problems in the setting of the solution, especially boundary and initial conditions and/or URFs. :)

Hi guy, have you solved your problem after there months?
I am interested in your things.
In CFDonline the avl-fire users are minor, maybe we can do more communication about fire incylinder calculation, to benefit both.

Regards
Song

Divergence during combustion simulation on AVL FIRE
 

Hello
I do have the same problem.
I have managed to make the solver complete a crank angle of 870 deg.
Now the solver is started to diverge.

Well one needs to use K - epsilon and not KZF model.
Try solving it and lemme know

salam
 

salam doki
I am master student of internal combustion engine and I am simulating the single phase boiling in a bottom heated rectangular duct . I used the defalt values for convergence criteria and under-relaxation factors , but the results devaiate alot with the experimental ones are so much . what convergence criteria and under-relaxation factors do you reccomand to use ?

hi dear Virkram
I am simulationg single-phase boiling in AVL Fire , but unfortunately the results diverged . I wanna to make my model(duct) in CFX and import it in AVL Fire, can you tell me how can I import my CFX-built model with its boundaries into AVL Fire?does the CFX-built boundaries would be recognized in AVL FIre?tell me how can I makemy model and its boundaries in a software(like CFX,ICEM,...) and import it in AVL Fire ?plz be in contact with me via E-mail : reza_hemmatdj@yahoo.com

Hi All,

I have created a model in Avl Boost and now I want to obtain 3d results with avl fire v2010 but I don't have any tutorials about it except Avl fire help.If you have some tutorials,can you send me? I don't know how I can run the programme,yet.Please help me. My email address is x.learner.y@gmail.com

Sena

Hi Vikram,

I am trying to learn Avl Fire 2010.But I don't have any tutorials.Could you send me some tutorials? I have a little time to finish my masters,but couldn't even run the programme.Please help me.

Looking forward to your reply

Sena

@vikram29586

I have been working on AVL fire for combustion simulation of DI Diesel Engine.

The first thing to check if the solution diverges is ur mesh. If ur moving meshes are perfectly made and appended, a dummy run must happen smoothly(without strucking).

If u r able to run the solver successfully with simple geometry and getting diverged solution with crevices, then the "selections" made might hav an error.

If everything is fine with meshing then we shall discuss on input data in solver steering file
:)

@hbganguly

AVL Fire is a 3D CFD simulation software used for combustion analysis, analysis of intake ports and manifolds, cooling jackets etc.
Results from AVL Fire combustion simulation include Emissions(NO,CO,HC,CO2,Soot,H20 etc), rate of heat release, pressure, temperature, turbulent kinetic energy, equivalence ratio etc,
combustion simulation videos can be saved and we can study the combustion pattern and spray pattern, turbulence, swirl etc.

Where as AVL boost is 1D simulation software whose results can be integrated with AVL Cruise and Fire for further analysis.(Cannot explain in detail since i never worked on Boost)
For eg: we can know that temp at piston head is 450 K from Boost and this result can be used in Fire for further analysis(just a vague guess)

Hi Saikrishna,

I am trying to learn Avl Fire.I am trying to run the example which I have downloaded pdf from avl website.Its name is 02_CFD-Getstarted_v2010_04_ESE_Tutorials.I have already entered the same datas with it.It is still continueing to run on my laptop.But, when I wanted to see engine specific output data,I couldn't see air fuel ratio,IMEP,ındicated power,indicated specific power,indicated specific torque,indicated torque and injected fuel mass.I see that all of them are 0.00E+000.Where do we enter these datas to Fire? Or does it calculate them?I am looking forward to your reply.Please help me.

Hi sena,

I am simulating combustion using AVL Fire CFDWM itself and i do not have ESE module activated.
From AVL Fire, we cannot get the direct results which were mentioned by you. If ESE gives the values directly specified by you and if it is showing 0.0 then either 1. u hav not activated the spray, or
2. the iterations still didn't reach the crank angle where fuel is injected
In AVL Fire,
Air fuel ratio can be calculated from equivalence ratio which is obtained from 2D Results. Power can be calculated from Rate of heat release (J/deg) values. Plot a graph between rate of heat release and crank angle and calculate the area of the graph. That gives the power. Injected fuel mass has to be given as input in solver steering file and can be checked whether correct mass is injected or not from "Spray:Liquid mass injected" column in 2D results.

and by the way, how could you get tutorial from avl website...can u send me the link

Hi Saikrishna,

Thank you for your reply :).Maybe as you said,my iterations didn't reach to angle which fuel is injected.I will wait for it.I can download them with my user name and password from avl website.If you don't have a password,you can not download them.But if you want,I can download for you.Which documents do you want?

Sena

And I would ask you if we could only simulate combustion with Avl Fire when both of the valves were closed.Or can we also simulate it when the valves are open?

@sena

I'll definitely ask u when i need some tutorials.
The simulation is done between IVC and EVO

Thank you very much for your reply and I will help you when you need them :)

Sena

But when we want to simulate whole of the cylinder (IVO,EVC,IVC,EVO),which version of Fire should I use? I heard about Fame but which Fame? I see that FAME Hexa,FAMETetra,FAMETopo,FAMEWrapper..Which one of them can we simulate whole of the cylinder?

Dear Saikrishna

I am still trying to obtain some simulation results with Avl Fire Ese Diesel.I am trying to decide my mesh number,so I firstly tried both 175000 meshes and 57000 meshes for the same case.If I don’t see any differences between them,I will do my other runs with 57000 meshes faster.But,I would ask you one thing about it. How can I compare the velocities or pressures or anything else along a line? For example; can I see the velocities at the center of the piston along center at different points? I don't know how I can do this.Please help me.

Sena

hi sena , use fame engine plus .

Hi All,


I have already done 1D analysis with Avl Boost.And now,I am trying to obtain some results with Avl Fire Ese Diesel. But I would ask you a question about it.My Air-Fuel Ratio is 16.86 which I saw on Avl Boost(1D analysis).But Avl Fire Ese Diesel gives me 37.4. I wrote in inital conditons on Avl Fire EseDiesel:

Egr Composition:0.0588
Egr Mass Fraction:0
Equivalence Ratio:0

How can I correct it to 16.86? The values don’t keep eachother . But total mass from 1D analysis and 3D analysis keep themselves. Please help me...

since u haven gave any equivalence ratio , fire shouldn be giving such a weird value .. can you send me your .fla file available in calculation folder to ayoshicfd@gmail.com ... i shall try my level best to sort this out

Hi,

Are you using Avl Boost? I would ask you a question about it.I can see mean pressure or total mass graphs but can not export the data of these graphs, how can ı do this? I want to obtain these datas of the graphs?

Kind Regards,

Sena

Dear All,

Although I can simulate the case with Ecfm-3z combustion model,unfortunately I can not simulate the same case with Eddy break up combustion model. What is the problem,do you think? What can I do? Please help me.

The comparisons can be made using Impress in work flow manager. There are different options in impress to make cuts which will navigate you to select the options like pressure, velocity, temp etc... A movie can also be generated in Impress. To better work with internal combustions I would go with fame engine plus :) It is kinda fuzzy at the beginning but you will enjoy it later on.

Thank you for your reply :).I did it already. I worked with Avl Fire Esediesel module.

Avl fire ese diesel resume problem
 

Hi all,

I'm working on AVL fire ese diesel module and actully I'm a very new user on it. After saving operation, I can not see my previous inputs. For example, I toggled the combustion model on and enter the all parameters and saved. But when I want to resume my model, I can not see combustion model toggle and my parameters there. But my previous engine parameters are still there but I dont know why just simulation parameters are missing.

Anyone can help me please on this ?

Hello friend i am final year mechancal student
 

i am doing my final year project on cfd analysis of direct injection diesel engine. for that i need a avl fire software and i cant afford to buy that software. i am so much in need of that software so kindly request u to where can i download the software for free atleast trial version .. plz tell me if u know .. plz plz............. also suggest me other softwares to do the project.

i am doing my final year project on cfd analysis of direct injection diesel engine. for that i need a avl fire software and i cant afford to buy that software. i am so much in need of that software so kindly request u to where can i download the software for free atleast trial version .. plz tell me if u know .. plz plz............. also suggest me other softwares to do the project.

i am doing my final year project on cfd analysis of direct injection diesel engine. for that i need a avl fire software and i cant afford to buy that software. i am so much in need of that software so kindly request u to where can i download the software for free atleast trial version .. plz tell me if u know .. plz plz............. also suggest me other softwares to do the project.

Hi dears
How can we choose the best value for Cfp?? for TFSC model

hii sir,
i have also observed this divergence problem during my simulation of diesel engine combustion. what i understood by checking that cases, if the mesh cell size is too large there is more possibility to diverge the solution.
so please try on this...and let me know about the result..

vikram sir,
i also posted some problems related to my solutions...please give a look on it and give me some suggestions...i am a master student doing my project in CFD
with regards
gafoor

AVL FIRE ESE simulation initial condition...
 

Hi Sena & friends,

I am doing a piston bowl optimization study using AVL FIRE
Hw can I assign the initial condition like EGR composition ?
I had a AVL boost model of the same where i can get the EGR mass fraction (eg:-Res.gas content [-] 0.0681).
But hw can i assign EGR composition & Equivalent ratio??

Plz guide...

Heat Release rate
 

Hello all.
I am doing my masters and need to validate an engine on AVL Fire.
I have nearly got P-theta diagram correctly.
But in Heat release rate I am facing problem.
Particularly in down slope of the curve and ignition timing.
What modification will help me ?

chethan......pls send me the details to my mail...i will check.....

Hi. .I wanna simulate HCCI diesel engine using AVL Fire. .how can I get start

Avl fire
 

Hi. .I wanna simulate HCCI diesel engine using AVL Fire software package. .how can I get start

Hello,
please i am using avl boost and ese diesel. i have read so many articles in which people used boost to obtain initial conditions for ese diesel. How do i obtain the initial condition values i need for ese diesel simulation from boost ?

hi
how can I run a multi-component fuel simulation in work flow manager for a diesel engine?
please help me. My email address is turaj.hashempur2@gmail.com

Thanks in advance