Application of a Piston Ring Dynamics Simulation Code to Solve Blow-By Fluctuation of a Heavy-Duty Diesel Engine in Transient Load Operation

For the development of engine components like pistons and rings, several numerical tools are employed of their performance evaluation in order to reduce the number of costly engine tests and samples required. An important limitation of the currently available codes that simulate piston ring dynamics is that they can be only used to study steady state engine conditions not allowing for the analysis of transient loads, for instance. This paper describes a proposed methodology for the simulation of transient loads yet employing existing codes. The method is used to study a real case of a diesel engine that showed excessively high blow-by fluctuations during its conventional running in cycle, more specifically at the load change from idle speed to peak torque. All assumptions and methodology are fully described, and predicted results for solution proposals are compared to engine tests in order to validate the procedure.