РОЗРАХУНКОВА МОДЕЛЬ ПРОЦЕСУ СТИСНЕННЯ ПОВІТРЯ З РІДИНОЮ В ЦИЛІНДРІ ДВЗ

Abstract

The paper discusses the features and performs a preliminary analysis of the symptoms and the causes of the connecting rod damage of an internal combustion engine caused by liquid entering the cylinder (hy­drolock). Object of the study is the cylinder of an internal combustion engine when liquid enters it. Purpose of the study is to research the mechanism of compression air with a liquid in the engine cyl­inder for identifying currently absent quantitative characteristics of the phenomenon of hydrolock, which causes deformation (buckling) and subsequent destruction of the connecting rod. Method of the study is theoretical, includes the development of a methodology for calculating the variation of the air parameters during compression air with a liquid. Based on simplifying assumptions, a system of differential equations for the pressure and temperature of the air with a liquid in a cylinder is ob­tained from the equations of gas state and energy. The system is solved by numerical integration over the crankshaft rotation angle with initial conditions were obtained using the standard ICE cycle calculation soft­ware. As a result, computation of the cylinder pressure in compression process by the crankshaft rotation angle depending on the filling ration of the combustion chamber with liquid was performed. The practical use of the methodology and the results obtained consists in their application in the problems of the engine damage simulation, including the calculations of the connecting rod buckling during hydrolock, as well as to clarify the symptoms and the causes of the damage. By calculation using the developed methodology, it was found that with an increase in the amount of a liquid, the maximum pressure in the internal combustion engine cylinder rapidly increases during compres­sion, starting with the combustion chamber filling ratio of 80%. With a further increase in liquid filling, commensurate with the volume of the combustion chamber, pressure rise in the final phase of the compres­sion stroke is possible tens or even hundreds of times, which determines the damage to the connecting rod during hydrolock. KEYWORDS: INTERNAL COMBUSTION ENGINE, ICE, CONNECTING ROD, CYLINDER, FAILURE, DAMAGE, HYDROLOCK, SIMULATION.