Improved model to determine turbine and compressor boundary conditions with the method of characteristics

Method of characteristics is still a powerful tool to incorporate variety of boundaries appearing in the internal combustion engines in the wave action techniques. Striving to the higher accuracy of one-dimensional techniques for modelling of engine manifolds leads to the necessity of considering variable properties and concentration of the gas. Innovative algorithm for the simulation of a turbocharger gas turbine and compressor based on extended equations of the method of characteristics is presented in this paper. This algorithm enables consideration of variable inlet and outlet pressure as well as consideration of variable gas properties and concentration. Improved model assures much better conservation of mass flow rate, when variable gas properties are considered, at only slightly increased computational time.