Abstract
A wrong TDC position leads to incorrect cylinder pressure-crank angle phasing, and has been recognized as a major source of error in thermodynamic calculation results such as indicated mean effective pressure, heat release rate, or thermal and mechanical efficiencies. One of the most convenient ways to determine TDC is to use measured cylinder pressure obtained from a pressure transducer under non-firing conditions. However, it is impossible to determine TDC precisely because the thermodynamic loss angle is unknown. In the paper a new method for TDC determination based on a measured non-fired cylinder pressure versus time diagram has been presented. In this method there is no need to know the details of the heat transfer formula, heat transfer coefficients or the properties of working gas in the engine . The method is applied to a four stroke high-speed marine diesel engine successfully. This method is distinguished for its high accuracy and is also probably applicable to large two stroke diesel engines.
