TURBINE

 TURBINE SECTION

The turbine transforms a portion of the kinetic (velocity) energy of the exhaust gases into mechanical energy to drive the compressor and accessories. The sole purpose of the turbine is to absorb approximately 60 to 70 percent of the total pressure energy from the exhaust gases. The exact amount of energy absorption at the turbine is determined by the load the turbine is driving (i.e. compressor size and type, number of accessories, and the load applied by the other turbine stages).

These turbine stages can be used to drive compressor (fan), propeller, and shaft. The turbine section of a gas turbine engine is located aft, or downstream, of the combustion chamber. Specifically, it is directly behind the combustion chamber outlet. The rotor element of the turbine section consists essentially of a shaft and a wheel (Fig.1-9). The turbine wheel is a dynamically balanced unit consisting of blades attached to a rotating disk. The disk, in turn, is attached to the main power-transmitting shaft of the engine. The exhaust gases leaving the turbine inlet nozzle vanes act on the blades of the turbine wheel, causing the assembly to rotate at a very high rate of speed.

The high rotational speed imposes severe centrifugal loads on the turbine wheel, and at the same time the elevated temperatures result in a lowering of the strength of the material. Consequently, the engine speed and temperature must be controlled to keep turbine operation within safe limits.

 







Comments

Post a Comment

Popular posts from this blog

Sub Module 7.18: Aircraft Non Destructive Testing (NDT) Techniques

Image
EASA PART 66 / SARI MODULE 7 NON-DESTRUCTIVE TESTING (NDT): Nearly all inspection operations on aircraft structures are carried out visually at intervals specified in the Approved Maintenance Schedule. Sometimes visual examination is not practicable, or there may be some uncertainty about the serviceability of a part and one of the methods of nondestructive examination may be used to determine its condition. Non-destructive tests seek to detect defects such as cracks or corrosion either at the surface of below it and a number of methods are presently in use. In each case the part being tested is not harmed in any way.  The selection of the method to be used will depend on the design of the structure, its accessibility and the nature of the suspected defect. 1. VISUAL INSPECTION Visual inspection is the oldest of the non-destructive methods of testing. It is a quick and economical method of detecting various types of cracks before they progress sufficiently to cause failure. Its reliabi
Read more

EWIS BACKGROUND AND TARGET GROUPS

Image
EWIS TRAINING BACKGROUND Over the years there have been a number of in-flight smoke and fire events where contamination sustained and caused the fire to spread. Regulators and Accident Investigators have conducted aircraft inspections and found wiring contaminated with items such as dust, dirt, metal shavings, lavatory waste water, coffee, soft drinks, and napkins. In some cases, dust has been found completely covering wire bundles and the surrounding area. Research has also demonstrated that wiring can be harmed by collateral damage when maintenance is being performed on other aircraft systems. For example, a person performing an inspection of an electrical power centre or avionics compartment may inadvertently cause damage to wiring in an adjacent area. Aviation Accident Investigators have specifically cited the need for improved training of personnel to ensure adequate recognition and repair of potentially unsafe wiring conditions. To fully realise the objectives EWIS, operators, ho
Read more

Approved Maintenance Organization | ANO145

 Essays: Question 1: You are the Quality Manager of an ANO-145 organization that carries out Line Maintenance of Boeing B777 Aircrafts. What requirements will you check before issuing the Certification Authorization to the Aircraft Licensed Mechanic in Category B1.1.  Question 2: An ANO-145 organization has a maintenance facility located outside Pakistan. What are the conditions under which the organization can use a certifying staff qualified in accordance with the national aviation regulations of the State in which the organisation facility is registered. Question 3: An aircraft is grounded at a location other than the main base where no appropriate certifying staff is available, how will the aircraft be released for service in this case.  Also write additional requirements for the maintenance organization if any. Question 4:  As per ANO-145 , what are different categories under which the aircrafts components must be segregated? Also explain how the unsalvageable items can be permitt
Read more