Development of praxeological principles to model/study heat generation and heat consumption processes in the engine of rapid internal combustion

Abstract

We consider a technology for modeling/studying phenomena of heat formation, heat transfer, heat utilization in the engine of rapid internal combustion, underlying which are the principles of praxeology. It is recognized that further development of classic approaches to modeling working processes in the engine relying purely or mainly on the analytical-algorithmic descriptions is almost impossible. It is therefore proposed to additionally introduce to the model an actual workspace of the engine, systemically connecting it to the virtual, implemented in the software-algorithmic environment, thereby introducing part of the reality to the model of the same reality. Within the framework of this study, we used, as a full-scale workspace, a cylinder from the tested engine BRIGGS&STRATTON, mounted at a special test bench. In this case, there is a possibility to greatly simplify the analytical component of the modeling representation of working processes in the engine, building it on the basis of classical analytical ratios that reflect the law of conservation of matter, the law of preservation of energy, a heat transfer law, as well as equations of thermodynamic state of a working body. The model acquires specificity not due to special empirical descriptions, but by acquiring current information from the real information space based on the principles of similarity theory. The required effectiveness of the model is provided by a simulation in the programming environment of interaction amongst itself and the environment of two zones into which a modeled engine workspace is split. A dual-zone model is opposed to the so-called multi-zone models, within which there is always a high risk of errors, almost uncontrolled, which require a complex and labor-intensive information support and maintenance. It is in the case of a two-zone representation of the modelled working space that it becomes possible to abandon the analytical control over chemical equilibrium in a working environment and there are no reasons that would predetermine the exchange of substances between zones. Therefore, it becomes possible to determine heat transfer to the walls of a working space similar to a single-zone model. It follows from the study conducted that it is expedient to apply a Wiebe function for the virtual simulation of a heat formation phenomenon. Quality of simulation is improved by acquiring information obtained in the process, so to speak, of on-line communication between a virtual (in the form of software) and an actual (in the form of a full-scale workspace) parts of the modelling environment. The presentation of the material is accompanied by illustrative material, which reflects information, obtained by modeling tools, about a change in: the working pressure in the engine working space, the temperature of a working body, an excess air coefficient, a heat transfer coefficient. We also included examples of change in the intensity of heat formation and intensity of heat transfer at the surface of: the working space in general, a cylinder liner, a cylinder lid, a piston head. Among the illustrations are the characteristics of the internal (intra-zone) heat exchange