Abstract

A universal thermodynamic model for calculating the workflow of “cylinder-piston” type systems which describes step by step the processes in the cylinder, and takes into account the real nature of the intake-exhaust and air leakage processes has been developed. Using the model, three completely different applied problems, including modeling hydrolock when fluid enters the cylinder of an internal combustion engine, modeling the dynamics of the catapult trolley motion during the launch of an unmanned aerial vehicle and modeling the engine indicator diagram during cold cranking when measuring compression were solved. Control modeling and comparison with known experimental data on the processes of air compression in cylinder with liquid (hydrolock), results of pressure measures in the engine cylinder during cold cranking and the known data of pneumatic launchers (catapults) showed the model’s overall reliability and its applicability for various applied tasks. This determines the model for possible use not only in designing devices of the type under consideration, but also for their operational diagnosing and troubleshooting of various types of damage.

Keywords:Thermodynamic model; Modeling; Cold cranking; Compression; Hydrolock; Diagnostics; Pneumatic launcher

Abbreviation:M, m: Mass; V, L: Volume and Length; F, f: Area; r: Relative Length, Radius; H, h: Height; S, x: Stroke (Piston) and Current Coordinate; τ: Current Time; φ, n: Rotation Angle and Rotation Speed; p, T: Pressure and Temperature; C, v: Velocity; T, R, F: Force; U, i: Internal Energy and Enthalpy; Q, L: Amount of Supplied (Removed) Heat and Work; Cv, Cp: Heat Capacities at Constant Pressure and Volume; γ, R: Air Adiabatic Index and Gas Constant; ε: Compression Ratio, Relative Volume; μ: Flow Coefficient