Digital Intake Valve Based CFD Investigations of a Single Cylinder Spark Ignition Engine to Improve Its Performance and Emissions Characteristics

This paper presents the results of the CFD research investigations on a single cylinder spark ignition engine modeled alternatively with a digital intake valve and a cam based intake valve. The results were computed in the thermodynamic simulation software AVL BOOST. The software uses the finite volume method along with the conservation equations of mass, momentum, energy and the equation of state for an ideal gas. The parameters computed were pressure, velocity, density and temperature etc. The emissions and performance parameters of the engine were simulated for both the conventional cam based valve and the digital valve. The digital intake valve was modeled for a constant maximum valve lift throughout the intake process where as the conventional cam based valve was modeled for variable valve lift on a crank angle to crank angle basis. The results showed that the engine with the digital intake valve gave better volumetric efficiency, power, torque and brake specific fuel consumption as compared to the engine using the conventional cam based valve. Further the engine with digital intake valve has better emissions characteristics as compared to the engine with cam based valve