<p>Stringent regulatory requirements
and modern diesel engine technologies have engaged automotive manufacturers and
researchers in accurately predicting and controlling diesel engine-out
emissions. As a result, engine control systems have become more complex and
opaquer, increasing the development time and costs. To address this challenge, Model-based
control methods are an effective way to deal with the criticality of the system
study and controls. And physics-based combustion engine modeling is a key to
achieve it. This thesis focuses on development and validation of a physics-based
model for both engine and emissions using model-based design tools from MATLAB
& Simulink. Engine model equipped with exhaust gas circulation and variable
geometry turbine is adopted from the previously done work which was then
integrated with the combustion and emission model that predicts the heat
release rates and NO<sub>x </sub>emission from engine. Combustion model is
designed based on the mass fraction burnt from CA10 to CA90 and then NO<sub>x </sub>predicted
using the extended Zeldovich mechanism. The engine models are tuned for both steady
state and dynamics test points to account for engine operating range from the
performance data. Various engine and combustion parameters are estimated using parameter
estimation toolbox from MATLAB and Simulink by applying least squared solver to
minimize the error between measured and estimated variables. This model is
validated against the virtual engine model developed in GT-power for Cummins
6.7L turbo diesel engine. To account the harmonization of the testing cycles to
save engine development time globally, a world harmonized stationary cycle
(WHSC) is used for the validation. Sub-systems are validated individually as
well as in loop with a complete model for WHSC. Engine model validation showed
promising accuracy of more than 88.4 percent in average for the desired parameters required
for the NO<sub>x </sub>prediction. NO<sub>x</sub> estimation is accurate for
the cycle except warm up and cool down phase. However, NO<sub>x </sub>prediction during
these phases is limited due to actual NO<sub>x </sub>measured data for tuning
the model for real time NO<sub>x </sub>estimation. Results are summarized at
the end to compare the trend of NO<sub>x </sub>estimation from the developed
combustion and emission model to show the accuracy of in-cylinder parameters
and required for the NO<sub>x</sub> estimation. </p>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/14501898 |
| Date | 10 May 2021 |
| Creators | Vaibhav Kailas Ahire (10716315) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/PHYSICS-BASED_DIESEL_ENGINE_MODEL_DEVELOPMENT_CALIBRATION_AND_VALIDATION_FOR_ACCURATE_CYLINDER_PARAMETERS_AND_NOX_PREDICTION/14501898 |
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