Heat Release Rate for IC Engine Spark ingnition ([e-mail])

</matlabcentral/answers/uploaded_files/79339/HRR%20CA%20Modify.jpg> Hello Every one I wrote a matlab code to find the heat release rate vs the crank angle from the pressure trace data and it looks like reasonable Now I want to integrate the heat release rate curve to get the heat release (I was told trapozed method) but I am not sure how to perform this integration in matlab Then I want to normalize the heat release curve to get the mass fraction burned The second question is how can I find the wiebe function parameters from the mass fraction burned (I need to do curve fitting but I am not sure how to do it (It looks like the matlab put some small circles over the curve to see the fitting ) Thank you

[Saif Salih]

here is the picture for the heat release rate

Answer 1

[Syah]

Hi Saif,

Yes, you can perform integration using trapezoidal method as below:

Q_hr( i ) = 1 / 2 * ( dQ_hr( i ) + dQ_hr( i + 1 ) ) * istep ; where istep is the crank resolution.

Then you can calculate the total amount of heat release. To get MBF just normalize it. Hope this answer your question.

Syahar