Gas Turbine TURBINES

Answer 1

~rotating the turbine causes the compressor,front fan and the accessory gearbox to be driven
~the high energy gas stream enters the turbine section via a set of nozzle guide vanes
These straiighten the airflow and ensure axial flow into the turbine
~turbine extracts kinetic enirgy wihtin the gas

Question 2

Turbine

Answer 2

Nozzle guide vanes and rator(turbine) in these sequence for the turbine

Question 3

Impulse reaction turbine blade

Answer 3

a fluid jet force drives against the blade which is the part near to the base(impulse),an aerodynamic force is reacting at tip of the turbine (reaction)

Question 4

The most limiting part (sensible)

Answer 4

Most limiting part in a turbine engine are turbines

Question 5

Impulse turbine

Answer 5

Nozzle&raquo_space;convergeent
Rotor»constant area (just a bucket)

The gas will increase velocity slightly with a slight reduction in a static pressure,tempereature wil continue to decrese (moving away from the source)

Question 6

STRESS IN BLADES

Answer 6

During full thurst bade can reach 66000g

The trubine are attached to the rotor disc using the “fir tree root”

~High cycle fatigue (HCF) high number of small stresses -attributed to vibrations
~low cycle fatigue (LCF) - low number of large stresses- reduced by lowering blade temperature and load charges

Single crystal tecnology

Always we try to keep the turbine temperature low

Question 7

Active cleareance control

Answer 7

Is controlled by fadec ,hp bleed air is feed to the small tubes to cool down

ACC(ACTIVE CLEARANCE CONTROL ) is controlled and monitored by FADEC

Question 8

Stagger angle

Answer 8

Balde twist for impulse/reaction turbine blades

Question 9

Impulse /reaction turbine

Answer 9

IMPULSE: 
~In the nozzle guide vanes
velocity : increase
pressure decrease
~rotor blades
Velocity :decrease
Pressure:constant

REACTION
~IN THE NOZZLE GUIDE VANES
Velocity:
Pressure : decrease
~IN THE ROTOR
velocity :decrease
Pressure decrease and temp