Chapter 1 - Role of simulation in the design cycle of complex technological systems
Keywords : mechatronic systems, V design cycle, functional level, inverse simulation, network level, model in the loop, software in the loop, hardware in the loop, co-simulation, geometric level, distributed parameters, lumped parameters, validation, verification, block diagram, network, bond graph, causal, acausal
Chapter 2 - Fundamental concepts of lumped parameter-based multi-physics modeling
Resume : Chapter 2 introduces the fundamental concepts of multi-physics modelling with lumped parameters. The general structure of the chapter makes it possible to deal with the different modelling levels encountered in mechatronic systems engineering. Simple examples illustrate the notions of lumped parameters and acausal modelling. The main physical concepts captured by multi-physics modelling (Kirchhoff laws and energy flows) are introduced and finally applied to an example of a car mechatronic system, the electric window lift. These principles of modelling will be taken again and applied on exercises where the models and the parameters will be known. They will be used to revise the fundamental concepts and to learn how to set up and simulate Modelica models.
Keywords : mechatronic systems, lumped parameters, causal, acausal, Kirchhoff’s laws, energy flows, functional level, signal level, network level, geometric level, Modelica, flow variables, connectors, differential-algebraic equations, energy conservation, power variables, power window system, incremental modeling, transformers, storage elements
Chapter 3 - Setting up a lumped parameter model
Resume : The objective of Chapter 3 is to introduce the reader to the implementation of a lumped parameter model. It is indeed often the responsibility of the engineer to determine for himself the model to represent a given system. An effort of abstraction is then necessary and the fineness of representation of the model to be put in place will depend on the type of excitation and the objective sought. The chapter will build on an example of a forced draft fan cooling tower. It will illustrate the deductive approaches that gradually increase the complexity of the model until the desired phenomenon is obtained, here the transient torque which can damage reducer during start of the electric motor, and the reduction approaches that make it possible to select the main elements from an initially complex model.
Keywords : steady state, quasi-static, transient, 0D/1D, 3D, activity index, inverse simulation, design of experiments (DoE), sensitivity analysis, equivalent parameters, power steering, submarine, common rail
Chapter 4 - Numerical simulation of multi-physics systems
Resume : Chapter 4 introduces the reader to the numerical aspects involved in multi-physic systems’ modelling. In a first step, the Bond-Graph formalism is presented and is used to build models based on physical effects. A particular focus is put on the model causalities, essential for computer simulation. In a second step, the reader will be sensitized to the mathematical principles necessary to both the modeller and the simulator, e.g. the different forms of equations usually used to model a system or the numerical integration necessary to solve these equations. Also, the main sources of errors related to virtual prototyping are discussed. Bond graph modelling of a submarine propulsion system will highlight the notion of causality conflicts and servo valve modelling will present mathematical singularities typically encountered in systems’ simulation.
Keywords : equation categories, DAE, ODE, PDE, algebraic relation, integration, differentiation, state space representation, block diagrams, causality, Block Lower Triangular, Bond graph, bi-causality, solver methods, simulation errors.
Chapter 5 - Dynamic performance analysis tools
Resume : Chapter 5 presents the tools used by the engineer in order to conduct the analysis of dynamic systems that characterize their temporal and frequency behaviour. These tools are mainly focused on the characterization of the transient response by using time and frequency performance indicators, and also make it possible to conclude on the stability of the systems. All the concepts discussed are illustrated on various technological examples, which are particularly suited for the study and will help to gain insight on these performance indicators. Thus, each performance indicator is first present and then it is shown how to obtain and use it for solving various problems related to dynamic systems. Since the analysis conducted in this chapter requires a particular formalism for the models – the transfer function – the chapter starts with an introduction to transfer functions.
Keywords : linear dynamical systems, transient response, frequency response, dynamic performance indicators, Laplace transform, transfer function, linearization, system stability, first order system, second order system, model reduction.
Chapter 6 - Mechanical and electrochemical power transmissions
Resume : Chapter 6 is an introduction to variational calculus modelling approaches. It first shows how it is possible to represent the main concepts of system modelling, introduced in Chapter 1, by theorems manipulating works and energies. These approaches make it easier to model devices that have no obvious location or decomposition of effects, or to determine parameter values for multi-domain devices such as actuators. Piezoelectric transducers will serve as examples of applications and illustrations to different approaches: virtual work theorem, energy balance or co-energies approaches, Lagrange equations. These approaches will then be re-applied to other examples of electromechanical actuators or mechanical power transmissions.
Keywords : variational principles, electromechanical transmissions, piezoelectric transducers, virtual work, energy or co-energy balances, Lagrange equations, elastic energy, electrostatic energy, magnetic energies, kinetic energy, potential energy, virtual displacement, power off brake, reluctance, fast steering mirror.
Chapter 7 - Power transmission by low-compressibility fluids
Resume : This chapter is an introduction to the modeling of power transmission systems by low compressibility fluids, which are often referred to as incompressible. It precedes a chapter dedicated to power transmission by high compressibility fluids, typically gases, such as the air. It is the reason why this chapter first introduces the context in which fluid power is used and the advantages of this technological solution. The guiding example in this chapter is an actuation system of the primary flight controls of a helicopter. The elementary components and the system are modeled using the bond graph formalism, presented in chapter 4. Bond graphs enable the structuring of models so that they rely on the physical effects of the components and are energetically correct. The fluid/thermal and fluid/mechanics couplings are then illustrated by simulation. The chapter closes with exercises and problems that illustrate the use of these models and the creation of their equivalents in Modelica language for other hydraulic applications.
Keywords : fluid power, hydraulics, fluid power transmission, actuation system, helicopter, hydraulic components, reservoir, pump, valve, pipe, cylinder, actuator, fluid properties, viscosity, density, compressibility, system performance, servovalve.
Chapter 8 - Heat power transmission
Resume : This chapter focuses on modeling systems for heat power transfer by fluid media and particularly on heat exchangers. The models presented here have various degrees of complexity, but all of them can be used within a system approach. The usage of these models is illustrated on an example of estimation of automotive radiator performances.
Keywords : heat exchangers, heat exchanger effectiveness, Number of Transfer Units, global heat transfer coefficient, Dittus-Boelter correlation, Colburn factor, fined surface efficiency, pressure drop, Darcy friction factor, Moody diagram, automotive radiator, double-flow controlled mechanical ventilation.
Chapter 9 - Thermal power conversion
Resume : This chapter completes the book with a modeling of systems that convert thermal power into mechanical power and vice-versa, by means of a compressible fluid. As a first step, several fluid models and notions of thermodynamics are presented. These are useful when modeling thermodynamic cycles and components of heat engines. The models presented are defined for steady state and have a level of complexity that enables their use in a system approach. Analysis or simulation illustrations of the use of these models are provided by examples of thermal power plants and heat pumps.
Keywords : heat engines, fluid modeling, thermodynamic charts, thermodynamic process, thermodynamic cycle, vapor cycle, refrigeration cycle, turbine modeling, compressor modeling, isentropic efficiency, power plant, gas turbine, heat pump.