Simulation of Turbocharged Reciprocating Engine Cycles

Garant předmětu:

Jan Macek

Lecturer:

Jan Macek

Tutor:

Jan Macek

Supervisor:

Department of Automotive, Combustion Engine and Railway Engineering

Synopsis:

Mastering of the thermodynamic simulation of complex engine or machine systems with 1-D compressible flows. Understanding of reasons to and acquiring of basic empiric closure functions of ICE. Mastering of engine cycle optimization.

Requirements:

Thermodynamics, gas dynamics and general mechanics. Numerical mathematics for solution of ODE (at least in the contents of master studies at FME CTU)

Syllabus of lectures:

1. Introduction - fundamentals of unsteady thermodynamic simulation, integral and differential forms of the law of conservation. Lagrangian, Eulerian and Leibnizian approach. Formulation of basic laws of conservation with convection, diffusion and source terms.

2. Species conservation: Description of

chemical reactions and phase changes. Momentum conservation in FVM.

3. Constitutive equations of working fluid (state equation and its derivatives,

enthalpy and internal energy of reacting mixtures). Energy conservation.

4. Fundamentals of Eulerian Q-D multi-zone model

of a reciprocating engine with common pressure. Inverse algorithm for evaluation of ROHR.

5. General appearance of ordinary differential equations set for 0-D model - OBEH (CYCLE code) example. Numerical features of right-hand side functions, stiffness.

6. Empirical correlations for the

rate-of-heat-release and semi-empirical Vibe model, calibration, knocking combustion. Heat transfer through walls, thermal resistances. Flows through valves. Mechanical losses of engine train.

7. Turbocharger 0-D and 1-D models. Exhaust system simulation results (interpretation of simualtion).

8. 1-D model of unsteady manifold flows. Set of partial differential equations. Theory of characteristics, Cauchy's task.

9. Shock waves, weak solutions and integral formulation of FVM. Boundary conditions. Unsteady heat transfer and its simulation. Types of boundary conditions. Iterations for the 3rd type boundary condition at variable heat transfer coefficient.

10. Further examples of interpretation of simulation results: uncooled engine, adiabatic engine, combus´tion patterns, cylinder charging analysis, internal cooling, dynamic effects. Fundamentals of model calibration and use of optimizers for finding model parameters.

11. Engine transients, detailed and real time simulations. Dynamics of solid bodies in engine model. Transport delays and piston flows. Control equipment.

Transient response

models - dynamics of turbocharged engines.

Syllabus of tutorials:

No.

Study Objective:

Mastering the thermodynamic simulation of complex engine or machine systems with 1-D compressible flows. Understanding of reasons to and acquiring of basic empiric closure functions of ICE. Mastering engine cycle optimization.

Study materials:

Heywood, J.B.: Internal Combustion Engine Fundamentals. McGraw Hill 1988 ISBN 0-07-028637-X

Stone, R.: Introduction to Internal Combustion Engines. SAE International 1999 ISBN 0-7680-0495-0

Morel, T. et al.: GT Power Code - Instructions for Use. Gamma Technologies, Inc., Westmont IL 2004

Note:

Further information:

https://studium.fs.cvut.cz/studium/u12120/W21O001_Matematicke_modelovani_obehu_SM/

Time-table for winter semester 2023/2024:

Time-table is not available yet

Time-table for summer semester 2023/2024:

No time-table has been prepared for the course in this semestr

The course is a part of the following study plans: