Session: 14-04 Systems

Paper Number: 84308

84308 - Gas Turbine Secondary Air Systems Modeling 

Modern gas turbine engine designers are challenged with aggressive power, cycle efficiency and operational life targets. Those targets are directly related with turbine inlet temperature, material selection and design choices. Increasing turbine inlet temperature, increases cycle efficiency and power output, however, operational life inversely affected. To optimize those contradicting targets, cooling and sealing design choices have to be carefully selected, which is main responsibility of Secondary Air Systems design engineer.

 

Generally, Secondary Air Systems (SAS) discipline is responsible to design cooling systems to prevent hot gas ingestion, to deliver cooling air to the turbine blades/vanes and also responsible to design heating systems to prevent ice accretion on inlet geometries. Additionally, SAS team is responsible for bearing chamber isolation, balancing and optimizing thrust bearing axial loads. To accomplish aforementioned design functions, SAS team sizes the restrictions and evaluates different design options. Since the thermal environment of a gas turbine engine is settled with SAS design, the analysis of SAS plays a very important role during the engine design process. Internal cooling flows are used to limit engine component temperatures providing adequate temperature distribution, improve engine efficiency, control thermal growth and consequently ensure required components life through their design and a capable materials selection.

 

Altair Flow Simulator© (FS) is an integrated multi-dimensional flow, thermal, and combustion modeling software that can be used for conceptual as well as detailed design and analysis for any thermo-fluid system design application. By using FS compressible/incompressible flow and heat transfer models can be created utilizing extensive model library including orifices, tubes, labyrinth seals, vortices and heat transfer correlations. It also includes a cavity modelling tool with robust solver, practical user interface and well known methodology.

 

This paper reviews the FS modeling methods that are commonly used for SAS design.  The methods to be reviewed include: orifice losses, rotating cavities and labyrinth seals. The component modelling results validated by comparing literature test data, company owned test data and Computational Fluid Dynamics analysis. Discharge coefficients for orifices, swirl ratio and windage temperature rise for rotating cavities and flow function values are compared for smooth and honeycomb landed labyrinth seals. A representative high pressure turbine network model is also created. One of the challenges during SAS design is evaluating effects of uncertainties caused by boundary conditions, manufacturing tolerances and empiric models. Effects of those uncertainties on disc purge air, blade cooling air is quantified by using probabilistic calculation capability of FS

Presenting Author: Mustafa Kocagul TEI TUSAS Engine Industries Inc.

Presenting Author Biography: Mustafa KOCAGUL was born in Izmir/TURKEY in july 11, 1985. He recieved his B.Sc. degree in Mechanical Engineering from Dokuz Eylul University, (Izmir/Turkey) in 2007 and his M.Sc. Degree in Mechanical Engineering from Istanbul Technical University (Istanbul/Turkey) in 2009. Since 2011 he was working in TUSAS Engine Industries Inc. (Eskisehir/Turkey) as Thermal Systems Design Engineer. <br/>Currently, Mustafa is working as Thermal Systems Design Staff Engineer and his main responsibility is technically leading Thermal Systems Design, Secondary Air Systems (SAS), Fuel Systems and oil systems design of TEI engine development programs. <br/>During his career, He is interested in secondary air systems design, thermal systems design of aircraft gas turbine engines; including prevention of hot gas ingestion, cooling system design, prevention of oil leakage from sump regions, axial load control, anti-icing system design, network modelling, sump region 1D thermal modelling, testing and instrumentation, test system installation, labyrinth seal and rotating cavity computational fluid dynamics analysis, oil and fuel system design and network modelling.

Authors:

Mustafa Kocagul TEI TUSAS Engine Industries
Ahmet Cihat Arıkan TEI TUSAS Engine Industries
Omer Uyav TEI TUSAS Engine Industries
Avni Ertas TEI TUSAS Engine Industries
James Bruns Altair Engineering Inc.
Aditya Jayanthi Altair Engineering Inc.