Hydraulic systems

What are the 3 main systems on aircraft?

Hydraulic, pneumatic, electric.

Hydraulic system

A system that utilises incompressible fluids to transform, distribute and use the mechanical energy of the fluid at high pressure.

What are the 4 main components of hydraulic systems?

Generation/transformation and regulation: pumps, valves, hydro-accumulators.

Distribution: pipes and fitting, control and command valves.

Users/consumer: motors/cylinders (rotary and linear).

Accessories: tanks, filters, heat exchangers.

What are the advantages of hydraulic systems?

Low weight per unit power

High efficiency in power transmission

Installation flexibility

Overload protection

High reliability

Reduced maintenance requirements

Low mass, ie. High frequency response

Ease of control

What are the disadvantages of hydraulic systems?

Highly interdependent - one component failure often means system wide failure.

Synchronisation - difficult to sync multiple actuators/users.

Fluid selection - fluids with better hydraulic properties tend to not be fire-resistant, the ability to transfer forces also allows fire to transfer.