With the dawn of electric transport, the research in Internal combustion engines seems fruitless, however, electrification of all transportation will consume a lot of resources and it's predicted that we won't switch all the heavy trucks and transport vehicles to electric power till 2050. The project I worked on with Sandia Labs, New Mexico and Prof. Satbir Singh at CMU aims to reduce NOx and COx emissions of IC engines. We achieve this through Exhaust Gas recirculation in a Passive Pre-chamber combustion IC Engine. We run the computational fluid dynamic simulations using a commercial solver CONVERGE CFD. The domain is shown in the figure. The experimental validation of the project is carried out by Sandia Labs to ensure we find the most efficient engine geometry to reduce emissions. 

The goal of the project was to develop a CFD modelling methodology that can accurately predict the combustion of a natural gas engine equipped with a pre-chamber spark ignition system. We found that previous studies did not use Turbulence Chemistry Interactions (TCI) for modelling the combustion inside the pre-chamber, this modelling technique aided the accuracy of our prediction. To aid the study even further we used the experimentally calculated values of pressure and temperature from Sandia Labs to initialize the simulations. The velocity contours of the simulation are shown in the figure. With these additional innovations, we accurately predicted the combustion process.

We also carried out several different experiments with different dilutions of the fuel using exhaust gases inside the pre-chamber to predict combustion for various conditions. This project is ongoing and the validated CFD model will be used to optimize the location of the spark plug and engine geometry to reduce NOx and COx emissions.

During the Summer I worked on devising and running the open-cycle simulations of the Passive Pre-chamber spark ignition IC engine. I validated the simulation by matching the temperature and pressure of the simulation against the motoring curve from the experimental data which is shown in the figure. The goal of my project was to find the mass fraction of exhaust gases before the next combustion stroke. The extent of the exhaust gases will affect the amount of dilution of the fuel for the next combustion stroke. Accurately predicting the mass fractions aids in accurately predicting the combustion of natural gas IC engines.