Skip to content
Provided by ASME Logo The American Society of Mechanical Engineers


Consider attending one of the Workshops and take advantage of the low registration fee. Registration will be available online. **Subject to cancellation if the minimum number of registrations is not achieved. Must register by April 22, 2019.


Workshop 1 – Physics-Based Modeling of Gas Turbine Secondary Air Systems

Sunday, June 16
8:00 am – 5:00 pm
Cost $300 per person

In gas turbines used for power generation and aircraft propulsion, the main flow paths of compressors and turbines are responsible for the direct energy conversion. To ensure acceptable life (durability) under creep, LCF, and HCF from operational transients causing high temperatures and their gradients in critical engine components, around 20% of the compressor air flow is used for cooling and sealing. This is analogous to blood, water, and air flow within a human body for its proper functioning. The main thrust of this Workshop is to develop a clear understanding of the underlying flow and heat transfer physics and the mathematical modeling of various components of gas turbine secondary air systems (SAS). In addition to developing a clear understanding of the key concepts of thermofluids, the Workshop will discuss vortex, windage and disk pumping in rotor/stator cavities, centrifugally-driven buoyant convection in compressor rotor cavities, pre-swirler systems, multiple reference frames, hot gas ingestion and rim sealing, and whole engine modeling (WEM) using nonlinear multisurface forced vortex convection links with windage in a layered approach. Additionally, the Workshop will provide a design-friendly overview of rotating compressible flow network methodology along with robust solution techniques, physics-based post-processing of 3-D CFD results, and the generation of entropy map for design optimization. A number of design-relevant examples will also be presented in the Workshop.

Notes: Five complimentary, autographed copies of Gas Turbines: Internal Flow Systems Modeling (Cambridge Aerospace Series) will be distributed among Workshop attendees using a random draw.

Learning Objectives

  • Develop a strong foundation in flow and heat transfer physics of various components of gas turbine secondary air systems
  • Develop an intuitive understanding of 1-D compressible duct flows under the coupled effects of area change, friction, heat transfer, and rotation
  • Gain knowledge in developing accurate physics-based and solution-robust secondary air flow network models
  • Gain knowledge in detecting input and modeling errors in their flow network models
  • Interpret results from their models for design applications.
  • Develop skills to hand-calculate results to perform sanity-checks of predictions by design tools as well as to validate these tools during their development and continuous improvement
  • Improve your engineering productivity with reduced design cycle time


8:00 am – 10:00 am
Module 1: An Overview of Secondary Air Systems

  • Role of Secondary Air Systems (SAS) modeling in gas turbine design engineering
  • The concept of physic-based modeling
  • Key components of SAS
  • Flow network modeling and robust solution techniques
  • Role of 3-D CFD in SAS modeling
  • Physics-based post-processing of CFD results
  • Entropy map generation and application

10:00 am – 10:15 am Break

10:15 am – 12:00 pm
Module 2: Special Concepts of Secondary Air Systems – Part I

  • Free vortex
  • Forced vortex
  • Rankine vortex
  • Windage
  • Compressible flow functions
  • Loss coefficient and discharge coefficient for an incompressible flow
  • Loss coefficient and discharge coefficient for a compressible flow

12:00 pm – 1:00 pm Group Lunch

1:00 pm – 2:00 pm
Module 3: Special Concepts of Secondary Air Systems – Part II

  • Euler’s turbomachinery equation
  • Rothalpy
  • Multiple reference frames
  • Pre-Swirler system
  • Rotor disk pumping

2:00 pm – 3:00 pm
Module 4: Physics-Based Modeling – Part I

  • Stationary and rotating orifices and channels
  • Rotor-stator and rotor-rotor cavities
  • Windage and swirl distribution
  • Centrifugally-driven buoyant convection in compressor rotor cavity with and without bore flow

3:00 pm – 3:15 pm Break

3:15 pm – 4:00 pm
Module 5: Physics-Based Modeling – Part II

  • Hot gas ingestion
  • Turbine rim sealing
  • Coupling with rotor-stator cavity purge flow and windage

4:00 pm – 5:00 pm
Module 6: Physics-Based Modeling – Part III

  • Whole engine modeling (WEM)
  • Multisurface forced vortex convection link with windage
  • Junction treatment in the network of convection links
  • Layered flow network modeling methodology
  • Key recommendations on SAS modeling

Earn 7 Professional Development Hours (PDH’s) and receive a certificate of completion!


Dr. Bijay (BJ) K. Sultanian, PhD, PE, MBA, ASME Life Fellow
Dr. Bijay Sultanian is an international authority in gas turbine heat transfer, secondary air systems, and Computational Fluid Dynamics (CFD). Dr. Sultanian is Founder & Managing Member of Takaniki Communications, LLC, a provider of high-impact, web-based, and live technical training programs for corporate engineering teams. Dr. Sultanian is also an Adjunct Professor at the University of Central Florida, where he has been teaching graduate-level courses in Turbomachinery and Fluid Mechanics since 2006. During his 30+ years in the gas turbine industry, Dr. Sultanian has worked in and led technical teams at a number of organizations, including Allison Gas Turbines (now Rolls-Royce), GE Aircraft Engines (now GE Aviation), GE Power Generation (now GE Power & Water), and Siemens Energy (now Siemens Power & Gas). He has developed several physics-based improvements to legacy heat transfer and fluid systems design methods, including new tools to analyze critical high-temperature components with and without rotation.

During 1971-81, Dr. Sultanian made landmark contributions toward the design and development of India’s first liquid rocket engine for a surface-to-air missile (Prithvi) and the first numerical heat transfer model of steel ingots for optimal operations of soaking pits in India’s steel plants.

Dr. Sultanian is a Life Fellow of the American Society of Mechanical Engineers, a registered Professional Engineer in the State of Ohio, a GE-certified Six Sigma Green Belt, and an Emeritus Member of Sigma Xi, The Scientific Research Society. He is the author of three graduate-level textbooks: Fluid Mechanics: An Intermediate Approach, published in 2015; Gas Turbines: Internal Flow Systems Modeling (Cambridge Aerospace Series), published in 2018; and Logan’s Turbomachinery: Flowpath Design and Performance Fundamentals, to be published in 2019.

For the ASME Turbo Expo 2019, he is the Heat Transfer Committee Point Contact, a role he also had for Turbo Expos 2013, 2016, 2017, and 2018.

Dr. Sultanian received his BTech and MS in Mechanical Engineering from Indian Institute of Technology, Kanpur and Indian Institute of Technology, Madras, respectively. He received his PhD in Mechanical Engineering from Arizona State University, Tempe and MBA from the Lally School of Management and Technology at Rensselaer Polytechnic Institute.