Cylinder pressure curves analysis

[21121956]

Hello everybody:

I am interested in obtaining information that deal with the analysis and interpretation of cylinder pressure curves for medium speed Diesel engines.

I am familiar with the use of the hand held electronic indicator HLV-94M (German manufacture) but I think that I need to know much more.

I will appreciate any collaboration.

 

[j2bprometheus]

Hi-

I have seen the cylinder pressure data aquired on numerous systems, including on oscilloscopes and an old Apple IIe computer. Several companies market systems to aquire cylinder pressure data, including AVL, FEV, Hi-Techniques, etc.

The first thing to make is a plot the log of pressure versus the log of the volume.

John B. Heywood's book on IC Engines mentions a little bit about calculating the heat release rate.

Is your diesel a direct injection engine or an indirect injection engine?

I'll send a little more info later.


j2bprometheus

 

[21121956]

Hi j2bprometheus:

Thanks for your comments.
Our engines are 18V46 of direct injection type.
The data captured with this equipment is downloaded to a computer, then we analyse the different generated graphs (cylinder pressure curves) and take decisions: no action is required, one or more injectors must be changed, and/or change one or more injection pumps, or simply readjust the rack of a particular injection pump.

Sometimes (thanks God are few ones) we have troubles with the interpretation of that graphs and, here is the point, when we need to have additional theoretical support.

 

[j2bprometheus]

Hi-

John B. Heywood's book on IC engines gives one of three methods for determining the apparent heat release rate from measured cylinder pressure. See Chapter 10, p. 510 of his book.


There is an SAE paper that gives the other two methods: SAE 900445 "Review of Simple Heat Release Computations" by B.M. Grimm and R. T. Johnson. This paper also lists some related references.

A consulting firm like AVL, RICARDO, FEV, etc. would happily analyze your cylinder pressure data or teach you how to analyze the data for a fee. They have computer code in house that would analyze the data.

Alternatively, you could hire someone to teach you how to analyze your cylinder pressure data. Some university professors have experience analyzing such data and might even have computer code already written to analyze the data.

You could write your own code to analyze the data. A package like MATLAB or DIADEM could run the code to do the data analysis and make the plots.


j2bprometheus

 

[bobqzzi04]

TFX engine technologies offers a nice acquisition/analysis set-up and software.