15.9 LUBRICANTS AND FUELS👌🏼 Flashcards
1
Q
Function of engine oil
A
- lubricating
- cooling
- cleaning
- corrosion protection
2
Q
What are the 2 types of engine oils
A
- synthetic
- minerals
3
Q
What are the 3 different type of synthetic oils
A
- type 1 (used on old gas turbines)
- type 2 (modern gas turbines)
- type 3 (higher thermal stability and viscosity at high temp than type 2) (used on special aircraft)
4
Q
Advantages of synthetic oils
A
- better viscosity
- better thermal stability
- high pressure resistance
5
Q
Drawback of synthetic oils
A
- expensive
6
Q
Explain viscosity index
A
- higher number = viscosity least affected by temp change
7
Q
Explain viscosity
A
- internal resistance of a fluid against deformation
8
Q
If viscosity is high what does that mean
A
Fluid is thick (viscous)
9
Q
Explain pour point
A
Lowest temp oil will visibly move
10
Q
What is the pour point for type 2 oils
A
-57*c
11
Q
Explain flash point
A
- lowest temp that oil will give enough vapour to flash when flame is applied
12
Q
What is the flash point for type 2 oils
A
> 250*c
13
Q
Explain oxidation resistance
A
- resists reaction between oil and oxygen
- when oil reacts with oxygen, it gets thicker (increases viscosity)
14
Q
Explain volatility
A
- liquid converted into a vaporous state
15
Q
Explain acidity
A
- measure of corrosive tendencies of the oil