Features of Mathematical Modeling in the Problems of Determining the Power of a Turbocharged Engine According to the Characteristics of the Turbocharger

The features of modeling the working process of a turbocharged two stroke marine diesel engine (MDE) in order to reveal the relationship between the engine power and the operation modes of a turbocharger (TC) are discussed in the article. Based on the results of modeling, a model was obtained for the dependence of the power of the MDE on the parameters of the TC operation. As a basic parameter of the TC operation, the TC speed was chosen. The scavenging air temperature is selected as an additional parameter. The article describes the structure of a diagnostic system that allows recording the operating modes of a TC in a noncontact method. The research for vibroacoustic fields of the G70-883kW marine engine was carried out by the author on ship “SEMINOLE,” in the process of research a noncontact vibroacoustic method was used to determine the TC speed. An analysis of the obtained experimental results demonstrates that the use of the averaged model of the dependence of the engine power on the TC speed for one engine family could lead to an error of 5-10%. The article shows that the results of experimental studies to determine the performance of a TC at various modes of operation of a MDE. The use of experimental data in the verification of simulation results has made it possible to reduce the error in determining the power of a MDE by 5-10%. The described method for estimating the power of a MDE based on the TC rotor speed and scavenging air temperature without using expensive piezoelectric type pressure sensors is an alternative method for estimating engine power.