The torque ratio concept for combustion monitoring of internal combustion engines
Journal article, 2012
This work presents a method to analyze combustion events in an internal combustion engine, called the torque ratio concept. The method is based on crankshaft
torque measurements, but an extension to angular speed measurements is possible. The torque ratio concept provides a parametrized model for the combustion
progress from which e.g. combustion phasing can be extracted. The torque ratio concept is derived mathematically and related theoretically to other combustion
analysis methods, such as pressure ratio and net heat release. Finally, analysis on recorded data from a five cylinder spark ignited engine verifies the relationships between the three methods. For combustion phasing, the 50% torque ratio is an equivalent measure to 50% pressure ratio and can be transformed into the 50% net heat release position by using a derived volume ratio function.
Engine management systems