Influence of imperfections in working media on diesel engine indicator process

Several improvements to the mathematical model Sor the indicator process in a diesel engine cylinder are proposed. The thermodynamic behavior of worki ng media is described by the equation of state valid for real gases. Analyt ical mathematical dependencies between thermal parameters (pressure, temper ature, volume) and caloric parameters (internal energy, enthalpy, specific heat capacities) have been obtained. These equations have been applied to t he various products encountered during the burning of fuel and the gas mixt ure as a whole in the engine cylinder under conditions of high pressures. A n improved mathematical model, based on the first law of thermodynamics, ha s been developed by taking into account imperfections in the working media that appear under high pressures. The numerical solution of the simultaneou s differential equations is obtained by Runge-Kutta-type method. The mathem atical model is then used to solve the desired practical problems in two di fferent two-stroke turbo-charged engines: 8DKRN 74/160 and Sulzer-RLB66. Si gnificant differences between the values calculated using ideal gas behavio r and the real gas at high-pressure conditions have been found. The numeric al experiments show that if the pressure is above 8 to 9 MPa, the imperfect ions in working medium must be taken into consideration. The results obtain ed from the mathematical dependencies of the the caloric parameters can als o be used to model energy conversion and combustion processes in other ther mal machines such as advanced gas turbine engines with high-pressure ratios .