Оценка скорости потока газов в системе поршень-цилиндр

Abstract

In the modern conditions the search for optimization solutions for the operation of marine diesel engines is becoming more and more topical. This conclusion may be reached when considered the tendency of their development from the standpoint of evaluating design methods, technical and technological improvement, and also the character of the findings conducted in that respect. Especially, it is common among the theoretical approaches used in the existing methods for showing cylinder thermodynamic processes. For the most part, quasistatic approaches are realized there in describing the nature of the change in parameters, implying that these processes are in equilibrium and reversible throughout the entire period of their course. However, as follows from the results of modern findings, the assumptions made do not fully reflect the real processes and for this reason their use is to a certain extent deterring the development of diesel engines by the factor. The study draws attention to the possibility of describing the operation of internal combustion engines from the viewpoint of gas dynamics, provided that the gas flow rate is estimated as a factor influencing the efficiency of thermodynamic processes. Insufficiency of information regarding accounting for the flow of gases in forced disturbances typical of diesel operation was established, which led to make an experimental setup that made it possible to reveal the regularities of the effect of the piston moved in the cylinder on the nature of the change in the gas flow rate. An algorithm is proposed for calculating the flow rate of gases by assuming that the velocity of propagation of gases moving under the influence of excess pressure and the rate of release of the cylinder volume by a moving piston is equal, which made it possible to determine the conditionally distinguished equilibrium line of the gas flow in terms of velocity. The data obtained as a result of the experience of the experiment are evidence of the reality of the assumptions made, and the methods imp; emented in the study can be introduced into methods for analyzing and calculating operating diesel engines.