GM Diesel Engine Simulation

In my Thermal-Fluid Systems class, we were asked to develop a model of the GM A20DTH 2.0 L engine based on the dual cycle and use it to determine engine performance for a variety of full- and part-load conditions over a wide range of engine speeds. I was with a team of four other mechanical engineering undergraduates for this project.

We programmed an algorithm to determine the states of the air throughout the engine cycle with turbocharging in MATLAB, and computed a handful of high-level engine performance parameters using this information. The algorithm was calibrated based on manufacturer data in order to determine empirical values of heat transfer and friction coefficients that were used to model these processes in the engine simulation. These preliminary results were assessed before refining the model to consider products of combustion using a thermodynamic property calculator, also implemented by our team in MATLAB (read more about that here). Engine performance was again considered for full- and part-load conditions; the effects of ambient pressure, engine air inlet temperature, and amount of fuel combusted at different stages on the power output of the engine were also analyzed.

Our model matched manufacturer data very well quantitatively for several parameters, such as the brake power, torque, and brake-specific fuel consumption. The model at least qualitatively matched manufacturer data for several other parameters as well, and the trends seen in our results seemed reasonable. The model improved when considering the combustion products throughout the cycle (rather than treating air as the working fluid throughout the entire process). We compiled our results into an engineering project report that was well-received by our professor.