Modelling of the operating process in a marine diesel engine

Abstract

ABSTRACTThe paper presents elements of a mathematical model of a marine diesel engine. The purpose of developing the model is to enable diagnostics of fuel supply and charge exchange system in a marine engine (simulation diagnostics). The authors have assumed the option allowing to modify geometric parameters of the crank-piston system, charge exchange, heat exchange and chemical composition of fuel. This option offers simulation of selected defects in an engine. The focus of the paper is both the process of model development and its implementation in an object-oriented programming language.Abbreviations: C: number of working cycles; c: specific heat; D: diameter; d: accuracy of calculations performed; i: iteration; j: value corresponding to subsequent working cycles; k: number of strokes; l: crankshaft length/air demand; m: mass; m: mass stream; n: number of cylinders; p: pressure; : heat stream; R: individual gas constant; r: length of crank arm; S: cross-section area; T: temperature; W: calorific value; w: flow velocity; V: volume; x: linear dimension; α: rotation angle; ρ: density; κ: adiabatic exponent; λ: air excess factor; μ: inflow/outflow factor; τ: time; cyl: refers to ‘cylinder’; chł: refers to ‘cooling’; ks: refers ‘combustion chamber’; max: refers to maximum value; o: refers to ‘theoretical air demand’; pal: refers to ‘fuel’; z: refers to ‘cylinder supply’; zaw: refers to ‘valves’; r: refers ‘real air demand’