Design and Simulation of a Multi Fuel Gas Mixture System of a Rotary Engine 2020-01-0548
The paper first includes the main objective and boundary conditions for design and simulation of a multi fuel gas mixture system of a rotary engine. New regenerative fuels are more and more important for use in automotive propulsion and stationary applications of combustion engines. Due the special design and operation of rotary engines there are opportunities for running these engines in future electric and hybrid applications with new designed liquids and gaseous fuels based on regenerative energy sources. The focus is on basic research and analyses of main physical and thermodynamic properties of separate lean burn gases (lower calorific value, mixed calorific value, AFR) and their effects on fuel mixing and combustion behavior. The work is focused on the development of simulation models capable to simulate the entire engine process and to map all factors influencing mixture formation and combustion of unconventional gaseous fuels. Moreover, analytical methods and modellation of the power estimation and fuel mixing are compared with 1d simulations of the fuel mixing and rotary engine thermodynamic performance. Analytical modells and calculations estimate the effective power, the mass flow of fuel of an additional fuel injection (in case of starting the engine and low calorific values of the lean gases) and the dimensioning of the mixture formation system. Later on there is a special focus on the modelling of a rotary engine with a commercial reciprocating engine simulation tool that need significant modifications for calculation of rotary engines. For this work, the autors created a new substitute engine model for running the special rotary engine thermodynamic process. The simulation contains the optimization of port timing combined with the intake time. At last, the mixture formation system coupled with the engine process. The results of the simulations and the analytical methods show the effects of separate design and thermodynamic parameters in combination with regenerative gaseous fuel on the BSFC and effective engine power. The work makes a fundamental contribution to the use of novel fuels in conjunction with specially designed internal combustion engines.
Tobias Dost, Joern Getzlaff
University of Applied Sciences Zwickau