Advanced Combustion Analysis: The development of an advanced combustion analysis tool
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Typ
Projektarbete, avancerad nivå
Program
Publicerad
2021
Författare
Ahmed, Aijaz
Edholm, Oskar
Lutimath, Ajanish
Raj, Avanish
Tagesson, Filip
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The main purpose of this project is to study and investigate advanced combustion
analysis in compression-ignited (CI) and spark-ignited (SI) engines. A MATLAB
code will be developed as the major deliverable, which will calculate the (apparent
and real) rate of heat release with the provision of different, effective intake valve
closing, heat transfer models, blow-by loss and gas properties with automatic polytropic
coefficient detection. This code will also be used to compare and validate the
different zero level corrections with commercial data acquisition software by Dewesoft
(stakeholder for this project).
For the study a 6-cylinder CI engine and am SI engine at Chalmers is used to record
the in-cylinder pressure. Measurements of the in-cylinder pressure accurately plays
an important role in pressure trace analysis. In this project, the experimental data
like raw cylinder pressure and crank angle degree is recorded with the Dewesoft data
acquisition system. Along with the recorded data, data from other test cells were
also collected which was further analyzed and processed through the MATLAB code
developed.
After the investigation, the common assumption of constant values of certain parameters,
such as IVC effective, constant polytropic coefficient, temperature at IVC,
wall temperature, heat transfer loss and blow-by loss was found to skew the data
significantly, thus giving incorrect results. Further, in-depth analysis for each of the
above parameters is done and function scripts were developed and integrated into
the main MATLAB program.
The major findings are that the commercial combustion analyzer software’s usually
considers a constant polytropic coefficient and also performs an apparent rate
of heat release, thus neglecting the heat transfer and blow-by losses. But in reality,
the polytropic coefficient varies and the heat transfer and blow-by loss do contribute
and affect the amount of heat energy liberated during combustion. The results from
the analysis of the data’s influence on the heat release is presented in the report.
Beskrivning
Ämne/nyckelord
Combustion , Analysis , Heat release