15.10 Flashcards
(32 cards)
What is the lubrication systems job
Distribute oil to bearings and gearbox’s as well as clean oil and warm fuel
What is a wet sump
Fuel falls to the bottom of the engine and is pumped up to the top by a pump. Not used on gas turbine engines
What is a dry sump
Closed system
Supply tank separate from engine
Supply pressurised oil to compartment
Used is gas turbine
What changes the pressure in a full flow oil system
No way of regulating pressure so The oil pressure changes with rotor speed (N2), and temp in flow areas down steam of pump
What drives the oil pumps in a full flow oil system
N2 HP compressor
What effect will an increase temp have on oil system
Oil will have a lower viscosity so higher flow rate and lower pressure
What lubricant system has a Pressure relief valve
Full flow
What is a constant pressure oil system capable of
Regulating pressure
Which oil system has a pressure regulation valve and what is this valve designed to do
Constant pressure system
Holds pressure at a given design pressure at all rotor speeds
Temp does not effect pressure
Which oil system is used on modern aircraft
Both full flow and constant pressure systems are used
What is the advantage of a full flow system
It is simple and needs no adjustments
What is the disadvantage of a full flow system
Needs high pressure at idle and there is a significant temperature rise after power reduction (not moving as fast so cooling decreases)
What are the two ways it fill oil
Gravity fill - added direct to tank
Pressure fill – Where a pressurised oil source is connected to a filling manifold. This connection is typically made using specialised adapters or fittings.
What is a scupper valve for
If oil is spilled during fill the valve takes it to a drain mast
What is an oil tank made of
Aluminium alloy coated in silicone
What is the brain if FADEC
EEC
What do All components of the engine have
Last chance filters
What is the most used pump for oil system
Gear pump
What are the two elements of a gear pump
1 for pressure oil
1 for scavenge oil
What elements make up a gerotor pump
1 element for pressure
Several for scavenge
Each scavenge line has own pump including gear box
Where would you find an oil pressure regulation valve and how can it be adjusted
Located in pressure side of the pump (constant pressure system)
Can be adjusted via screw
Pressure relief valve (oil system)
Full flow
Makes sure there is never over pressure especially when oil coolers are in the engine
What is the purpose of a bypass valve in an oil system
To maintain oil temp of pressure by verying the total flow through the cooler
What the the two types of heat exchangers
Fuel cooled
Air cooled
