Week 11: Project 2 - Emission characterization on a CAT3410 engine
Objective:
To run a 3D simulation of a CAT3410 diesel engine using two different piston bowl profiles and to understand the effect of piston bowl geometry on the performance and emission characteristics of the engine.
Geometry:
A tool called Make engine sector surface is used to create the engine the engine sector model and to perform the closed cycle analysis. The reason behind generating engine sectors is that the geometry is symmetric about its axis and by using periodic boundary conditions at the forward and backward face; the entire combustion chamber can be simulated using a sector, thereby saving a lot of computational resources.
For a Diesel engine, the fuel injector is mounted exactly at the center of the cylinder head and it will have multiple nozzles. In this case, the spray will be symmetrical. Hence to increase the computational efficiency, one sector of the engine is taken and combustion is simulated with it. It will lead to faster run times. This is called sector modeling.
Setup:
Converge studio provides us with a separate application for IC engine flow.
Materials:
Simulation Parameters:
Boundary Conditions:
Regions and Initialization:
Spray Modeling:
Geometry Mesh & Embedding:
Adaptive mesh Refinement:
Results:
Pressure Plot
Mean Temperature Plot:
Conclusion:
The simulation of the sector model is done i.e. Open-W type piston and Omega type of CAT 3410 diesel engine and their parameter plots and performance parameters are compared. The Omega-type piston outperforms the Open-W type in many critical factors and is 11.16% more efficient than the latter with lesser concentrations of Hiroy soot, UHC, CO generated in the former one. The NOx concentration was higher in the Omega piston due to the higher cylinder temperatures. NOx emission can be reduced by primary methods such as retard injection, fuel nozzle modification, change of compression ratio, water direct injection, water emulsification, exhaust gas recirculation (EGR), and secondary method such as selective catalytic reduction (SCR).