[kelvinlim]

Hi everyone,

I am final year undergraduate student from Putra University of Malaysia.

For your information,my project work is

"Computational Fluid Dynamic of Combustion Process in Gasoline HCCI Engine"

I am very new to this CFD and I need some advises/ideas from the experienced here regarding what will I going to do in this coming one year time?

I already do some research and literature on HCCI engine and I understand how it works.My main problems is CFD as I have no experience in this.

I will be using Gambit+Fluent solver 5/6 for my work later on.....

(I am still doing study on what is CFD and try to understand it at the moment)

Here are my question:

1.In modelling geometry the engine using Gambit,normally which necessary of engine I need to draw?This include cylinder chamber,piston,valve,and what
else?

2.After I finish create the 3D Volume/model of engine,I need to do mesh right?normally what mesh will I use and i should mesh on which part of the engine?
Which types of mesh should I use?cooper?
As I know,my work will be related to 4 stroke engine which involve piston
moving,so dynamic mesh will be more suitable is it?
Or should use try and error on the mesh and get the best skewness result?<0.6?

3.And normally what boundary condition we choose when we doing combustion simulation on ICE?

Feel free to email me to limguozhong@yahoo.com
or post here and I will be very appreciate

Thank you

Best Regards,
Lim Guo-Zhong
Undergraduate Student of Mechnical Engineering
Universiiti Putra Malaysia

[Graham81]

Dear Lim,

Modeling combustion in compression ignition engines is a very challenging CFD task because it combines a number of complex parts:

- Two-phase flow (fuel injection)
- Turbulent reacting flow (non/partly-premixed conbustion)
- Moving meshes (piston)

Without trying to take the place of your graduation mentor I would suggest building all these complexities in a "layer-by-layer" type approach.

Perhaps you can start by modeling the jet injection, breakup and evaporation of fuel, as the mixture formation will be the important starting field for subsequent combustion modeling. The engine combustion network (http://www.sandia.gov/ecn/) has a lot of data available for inert fuel injection.

When you are satisfied with how your model predicts mixture formation, you can have a go at combustion.

Finally, when all of this works in a constant volume, try moving meshes and compression ignition. But I think going through all this within one year in an academic manner will be very challenging . Good luck though and keep us posted!

Best regards,

Graham

[tsram90]

I think you should start low. Don't go straight to 3d modeling with valves and what not..

Do a 2d analysis of the cylinder portion alone first.
It will use dynamic mesh. Then try 3d. Then If you still have time(for project submission,) go for valves etc.