Simulation Tools for Development of Advanced Engine Braking and Variable Valve Actuation Systems

Simulation tools are essential for the development of advanced engine braking and variable valve actuation systems. GT-Power with a valve lift user model, which includes effects such as valve-train compliance, is used to predict engine performance, valve lift, and cylinder pressure. MATLAB/Simulink with a hydraulic/valve-train dynamic library is used to evaluate factors relevant to system design such as hydraulic circuit pressures, cam follow, valve-seating velocity, and parasitic loss. CFD is used in hydraulic component design and to provide flow resistance data for the system simulation. FEA is used together with the system simulation to evaluate the design durability, including prediction of impact loads. These tools have been applied to the development of a wide range of compression-release braking and variable valve actuation systems, including recent lost-motion and common-rail designs.