Theoretical model to determine effect of ingress on turbine disks

Isobel Mear, J. Michael Owen, Gary D. Lock

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Sealing air is used in gas turbines to reduce the amount of hot gas that is ingested through the rim seals into the wheel-space between the turbine disk and its adjacent stationary casing. The sealing air attaches itself to the rotor, creating a buffering effect that reduces the amount of ingested fluid that can reach the surface of the rotor. In this paper, a theoretical model is developed, and this shows that the maximum buffering effect occurs at a critical flow rate of sealing air, the value of which depends on the seal geometry. The model, which requires two empirical constants, is validated using experimental data, obtained from infrared (IR) temperature measurements, which are presented in a separate paper. There is good agreement between the adiabatic effectiveness of the rotor estimated from the model and that obtained from the IR measurements. Of particular interest to designers is that significant ingress can enter the wheel-space before its effect is sensed by the rotor.

Original languageEnglish
Article number032502
JournalJournal of Engineering for Gas Turbines and Power: Transactions of the ASME
Volume138
Issue number3
DOIs
Publication statusPublished - Mar 2016

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Turbines
Rotors
Seals
Wheels
Air
Infrared radiation
Temperature measurement
Gas turbines
Flow rate
Fluids
Geometry
Gases

Cite this

Theoretical model to determine effect of ingress on turbine disks. / Mear, Isobel; Michael Owen, J.; Lock, Gary D.

In: Journal of Engineering for Gas Turbines and Power: Transactions of the ASME, Vol. 138, No. 3, 032502, 03.2016.

Research output: Contribution to journalArticle

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