Aircraft hydraulic systems

Question 1

What is the purpose of Hydraulics?

Answer 1

The transformation, distribution and utilisation of mechanical energy through use of incompressible fluid at high pressures

Question 2

What type of device generates and maintains pressure in the system?

Answer 2

Pumps
Valves
Hydro-accumulators

Question 3

What are the positives of Hydraulic Systems?

Answer 3

Low weight per unit of installed power
High efficiency of power transmission
Ability to withstand overloads with out damage
High reliability
Reduced maintenance

Question 4

Which systems are powered by Hydraulics?

Answer 4

Extraction and retraction of landing gear
Air brakes
Wheel brakes
Nose wheel steering
Flight controls
Control surfaces
Thrust reverser
Doors

Question 5

Advantages of high pressure systems?

Answer 5

Components and piping can be lighter and smaller

Question 6

Which type of pumps work on the fluid dynamic principle?

Answer 6

Centrifugal
Axial
Hydraulic shock
Magnetofluid-dynamics

Question 7

Which type of pumps work are volumetric?

Answer 7

Piston
Gear
Love
Membrane
Screw
Rotary vane

Question 8

What is the required number of pistons for smooth operation of piston pumps?

Answer 8

7-9

Question 9

How does operating pressure affect the flow capacity of+ displacement pumps?

Answer 9

It decreases due to loss of volumetric efficiency

Question 10

Why should Pressure=k in hydro systems?

Answer 10

1) sizing of actuators is based on constant pressure and calc. external load
2) No interference between multiple consumers

Question 11

What are the methods of flow control for volumetric pumps?

Answer 11

1) Pump with constant delivery wi5 regulator valve in a hydraulic pipeline downstream of a pump
2) pump with variable flow delivery