Gas Turbines Flashcards
What is the definition of a working fluid?
Any gas or liquid that can do work by expansion or flow, or can be compressed or made to flow
What is the definition of a turbine?
A bladed spool designed to rotate when acted on by a working fluid
What is the definition of a compressor?
A bladed spool designed to do work on a fluid when it is rotated
Purpose of a gas turbine?
Gas turbines covert best entertainment into rotary motion for ship propulsion
Name 4 propulsion configurations
IEP
CODLAG
CODGAG
COGOG
Name 2 propulsion configuration meanings and shops there used on
IEP- integrates electric propulsion ( Type 45.)
CODLAG- combination of diesel electric and gas (Type 23.)
Name 5 advantages of a gas turbine?
- allows the ship to get underway quickly
- ease of operation and emphasis on remote control
- high power to weight ratio
- minimum ship-borne maintenance
- lower man- power requirement
Describe the intake system
- Air is drawn from the upper deck via a 3 stage filter
- removing particle and moisture contamination
- there is also a Manometric leg to ensure no unfiltered air enters the intake system
Name stage 1 of the air intake filters and what each process involves
-Stage 1- Spray Eliminator ( encourages the air to let go of any water), aluminium fins change the direction of the air, catching the spray and causing the majority to drop off and mainly dry the air passes through.
Name stage 2 of the air intake filter and the process?
-Stage2- Knitmesh filter ( aluminium fram supporting woven material), removes particular matter
Name stage 3 of the air intake filter and the process?
-Stage3- Water separation (manometric leg) (U-bend principle)/ water drains into a water troughs, which ensures a water seal across the bottom of the filters
After all stages of the air intake filter is complete, air leaving the filter unit is considered to be?
Water and dirt free
What is a splinter silencer?
- The splitter silencer splits up the air flow stream which reduces air noise and buffeting
- Air passes over aerofoil shaped canes which “straightens” the air flow and reduces resistance to air flow
What is a stone guard? And what’s it made of?
Prevents large/ coarse particles ( bits and beaks) of debris from entering the gas turbine
1-inch wire mesh to prevent damage
Imbalance causes vibration ie. ( brick in a washing machine)
What is a transition duct?
A transition duct provides a smooth change from square cross section air flow to circular air flow, in preparation for entering the engine air intake casing. (Minimises turbulence)
