7Power Transmission by Low-Compressibility Fluids
Summary
This chapter is an introduction to the modeling of power transmission systems by low-compressibility fluids that are often referred to as incompressible. It precedes a chapter dedicated to power transmission by high-compressibility fluids, typically gases, such as 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.
Learning outcomes
On completing this chapter, the reader is expected to:
- – Acquire knowledge on the main components of a fluid power actuation system;
- – Model the hydraulic power transmissions using the bond graph formalism or Modelica language;
- – Understand the multi-domain couplings specific to fluid power.
7.1. Fluid power
7.1.1. Context
Fluid Power applications use pressurized hydraulic fluid, generally ...