Table of Contents
22.1 The air system.
Fig. "Tasks of an air system": The ventilation of the rotor can serve different purposes.
- Lowering the thermal stresses. Usage of the higher strength of the colder material.
- Influencing the expansions/gaps between rotor and static components, especially also during unsteady/transient operation.
- Avoidance respectively minimising of rotorbow(volume 2, Ill. 7.1.2-9) adequate influencing of the component temperatures in the shut down phase and the start phase.
- Avoidance of „heat soaking“ with coking of the bearings and the oil supply (jets, lines, Ill. 22.3.2-6 and Fig. "Operation influennces of main bearings") by sufficient temperature drop, already in the shut down phase.
The separation of air from the oil is carried out mostly by a so called breather (also breezer, bleeder, Fig. "Oil system components"). With it defoaming takes place to guarantee the cooling effect/lubrication effect of the oil. Bleedair for air conditioning, respectively ventilation. Here the risk of annoying odour nuisance up to the danger of toxication exists if the air seals against oil guiding/containing regions are not sufficient (Ill. 19.2-9 and Fig. "Survey of cockpit crew").
References
22.1-1 I.E.Traeger, „Aircraft Gas Turbine Engine Technology, Second Edition”, Verlag:
Glencoe/McGraw-Hill 1994, ISBN 0-07-065158-2.
22.1-2 M.J.Kroes, T.W.Wild, „Aircraft Powerplants, Seventh Edition“, Verlag: Glencoe/McGraw-Hill 1995, ISBN 0-02-801874-5.
22.1-3 „The Jet Engine”, 5th Edition, Rolls-Royce plc, 1986, ISBN 0-9021231-2-35.
22.1-4 K.Bauerfeind, „Steuerung und Regelung der Turboflugtriebwerke“, Birkhäuser Verlag: 1999, ISBN 3-7643-6021-6.