Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

M11 > 11.11 HYDRAULIC POWER > Flashcards

11.11 HYDRAULIC POWER Flashcards

1
Q

What is Hydrostatic pressure

A

Pressure produced by static build up in aircraft hydraulic system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is hydrodynamic pressure

A

Pressure produced by moving liquids ideally with no friction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Explain open-centre

A
  • series
  • only operate 1 component at a time
  • slower as pump
  • selector valve for each system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain open-centre

A
  • series
  • only operate 1 component at a time
  • slower as pumps Needs to supply high pressure (delay)
  • selector valve for each system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain closed centre

A
  • parallel connection
  • multiple sub-systems can be used at one time
  • Pressure build up if selector valve is neutral
  • quicker response due to pressure build up
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain viscosity

A
  • Internal resistance to flow
  • Viscosity increases as temperature decreases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Explain flash point

A

Temperature at which liquid gives off vapour in sufficient quantity to ignite momentarily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain Fire point

A
  • temperature at which a substance gives off vapour in a sufficient quantity to ignite and continue to burn
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

3 types of hydraulic fluids

A
  • minerals
  • polyalphaolefins
  • phosphate esters (skydrol)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 2 classes of Phosphate Ester-based fluid (skydrol)?

A
  • class 1 fluids are low density
  • class 2 fluids are standard density
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

2 types of main servicing activities for hydraulic systems

A
  • Reservoir filling
  • Fluid sampling
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 2 ways reservoirs can be filled

A
  • manually
  • pressurised
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where is the hydraulic sampling valve located

A
  • HP manifold of each hydraulic system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are we looking for when carrying out a Hyrdraulic fluid sampling

A
  • checks for water contamination
  • reduction in fluid performance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How often is Hydraulic sampling scheduled

A
  • every 1 year
  • every 3000 flight hours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

If hydraulic contamination is suspected what should be done

A
  • fluid should be drained and replaced
  • samples should be taken too
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the function of the Hydraulic Reservoir

A
  • storage
  • replenishes fluid lost through leakage for operational needs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When are non-pressurised reservoirs used

A
  • aircraft that do not fly at high altitudes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When are pressurised reservoirs used

A
  • high altitude
  • usually reservoirs located in non-pressurised areas like wheel wells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a pressure relief valve

A
  • prevents excess pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do you de-pressurise between the pump and the user?

A
  • operate flight control to force fluid back to reservoir
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the 2 servicing activities for hydraulic systems

A
  • Reservoir filling
  • Fluid sampling
23
Q

Where is the Reservoir pressurisation module installed and what is its function

A
  • Installed close to reservoir
  • supplies aircraft bleed air to reservoirs
24
Q

What are the 2 types of accumulators used on aircraft

A
  • Spherical
  • Cylindrical
25
Q

What is the accumulator charged with

A

Compressed nitrogen

26
Q

What are the 2 ways hydraulic pumps are classified

A
  • positive displacement
  • non-positive displacement
27
Q

Explain constant delivery pumps

A
  • deliver fixed quantity of fluid per revolution despite pressure demands
28
Q

Explain gear type power pump

A
  • e.g. of positive displacement pump and delivers constant volume
  • 2 meshed gears, during gear driven by aircraft engine etc
29
Q

Explain RAT

A
  • variable displacement pump
  • retract only on ground
  • provides electrical and hydraulic power
30
Q

Explain PTUs

A
  • transferring power
31
Q

Explain electrically drive hydraulic pumps

A
  • electrical motor that’s mechanically connected to hydraulic pump
32
Q

Where does the tiny particles of metal from hydraulic fluid usually come from

A

Normal wear of selector valves, pumps, and other components

33
Q

What are hydraulic system filters for

A
  • filter out contamination from hydraulic fluid
34
Q

Explain wire mesh filters

A
  • made of steel
  • usually used for surface cleaning
35
Q

Explain stainless steel filters

A
  • like wire mesh but only stainless steel is used
36
Q

Explain micro glass filters

A
  • provides the best filtration quality
  • prevent passage of solids >10 microns
37
Q

Explain cellulose paper filters

A
  • made from resin-impregnated cellulose filter
38
Q

What are the common pressure relief valves

A
  • ball type
  • sleeve type
  • poppet type
39
Q

What are hydraulic seals

A
  • to prevent fluid from passing a certain point
  • to keep air and dirt out the system
40
Q

Seals are divided into 3 main classes

A
  • Packings
  • Gaskets
  • Wipers
41
Q

Hydraulic seals used internally on sliding assembly are called

A

Packing seals

42
Q

Hydraulic seals between non-moving fittings and bosses are called

A

Gaskets

43
Q

Red o-ring

A
  • for fuel
44
Q

Blue o-ring

A
  • For hydraulic fluid
45
Q

Advantage of back up rings

A
  • do not deteriorate with age
46
Q

What are backup rings

A
  • ## helps support the seal and acts as a seal
47
Q

When would a back up ring be used

A
  • when a single seal itself is not enough
  • e.g. pressure acting on the right of the seal pushing it out of position which could damage it
48
Q

When are static seals used

A

Against steady or pulsating pressure

49
Q

When are dynamic seals used

A
  • Seal where stroking or rotational movements occur
50
Q

Gaskets are used as static or dynamic seals?

A

Static

51
Q

Which valve is hydraulically operated
- shut off valve
- mechanically operated
- priority valve

A

Priority valve

52
Q

Explain non-return valves

A
  • allow fluid to flow in one direction and prevents/restricts flow in another
53
Q

What are hydraulic fuses

A
  • shuts off fluid flow if it detects a sudden increase in flow
54
Q

Hydraulic actuators page 143

A

M11 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions