University of Nevada, Las Vegas, NV, USA

Nonisentropic compressible flows are ubiquitous in many mechanical, chemical, and aerospace engineering applications, including gas turbines in their inlet systems, compressors, combustors, turbines, and exhaust systems. One-dimensional treatment of these flows forms the basis for most preliminary/conceptual designs. They are, however, generally counter-intuitive. For example, it defies common sense that the wall friction accelerates a subsonic compressible flow in a constant-area duct with or without heating. This workshop will provide a comprehensive review and reinforcement of the key concepts of one-dimensional compressible flows with simultaneous area change, friction, heat transfer, and rotation, which is seldom found in a textbook. In addition to the key concepts of thermofluids such as stream thrust, impulse pressure, rothalpy, mass flow functions, impulse functions, and normal shock function, this workshop will present an easy method to compute pressure and temperature changes in a generalized vortex in both rotor and stator reference frames. The workshop will conclude with a design-friendly overview of a compressible flow network featuring internal choking and normal shocks along with robust solution methods. A number of design-relevant examples will also be solved in the workshop. It behooves CFD engineers to use the unique foundation developed in this workshop as a prerequisite for all their 3-D CFD analyses, including physics-based interpretation of boundary conditions and computed results for design applications.

- Will develop a unique intuitive understanding of isentropic and nonisentropic compressible flows, including the coupled effects of area change, friction, heat transfer, and rotation
- Will develop a strong foundation in the physics-based thermofluids design of various engineered components
- Will be more knowledgeable in developing physics-based compressible flow models and applying accurate boundary conditions
- Will be more knowledgeable in correctly interpreting results of their compressible flow design analyses
- Will develop skills to hand-calculate compressible flow results to perform sanity-checks of predictions by design tools as well as validate these tools during their development
- Will improve participant's engineering productivity with reduced design cycle time

This workshop will be of interest to graduate students, research workers in universities and research institutes, and research and design engineers in industry who are involved in the physics-based thermofluids design and technology development of various components and systems, including high-performance gas turbine components such as inlet systems, compressors, combustors, turbines, diffusers, exhaust systems, internal air systems, and turbine airfoil internal and film cooling.

BIJAY K. SULTANIAN

Registration will be limited to 30 participants.

Five complimentary, autographed copies of **Fluid Mechanics: An Intermediate Approach** (2015) will be distributed among workshop attendees using a random draw.

ASTFE
Tel: +1 203 733 6275

Fax: +1 203 456 6167

© Copyright reserved ASTFE, 2024

American Society of

Thermal and Fluids Engineers

Fax: +1 203 456 6167

© Copyright reserved ASTFE, 2024

- What is a physics-based modeling?
- What are 1-D, 2-D, and 3-D CFD analyses?
- Fundamental difference between a compressible flow and an incompressible flow (beyond constant density!)
- A new interpretation of total pressure in an incompressible flow
- Stream thrust and impulse pressure
- Physics of Mach number of a compressible flow
- Physics of choking and normal shock phenomena
- Concept of rothalpy
- Converting total properties between rotor and stator reference frames
- Concept of entropy
- Computation of entropy change between two points
- Generating entropy map from 3-D CFD results

- Total-pressure mass flow function
- Static-pressure mass flow function
- Loss coefficient versus discharge coefficient
- Total-pressure impulse function
- Static-pressure impulse function
- Normal shock function

- Isentropic compressible flows
- Isentropic flow with area change
- Operation of a converging nozzle
- Operation of a converging-diverging nozzle

- Conservation equations
- Fanno flows
- Property changes in a Fanno flow
- Use of Fanno flow tables
- Rayleigh flows
- Property changes in a Rayleigh flow
- Use of Rayleigh flow tables

- Normal shocks
- Normal shock using Fanno and Rayleigh lines
- Characteristic Mach number
- Normal shock relations
- Normal shock tables
- Locating a normal shock in a converging-diverging nozzle

- Vortex versus vorticity
- Free vortex, forced vortex, and Rankine vortex
- Generalized vortex
- Pressure and temperature changes in isentropic free and forced vortices
- Pressure and temperature changes in a nonisentropic generalized vortex

- Element modeling
- Total-pressure-based formulation (not physics-based!)
- Static-pressure-based formulation
- Junction modeling
- Handling internal choking and normal shocks
- Determining element flow direction under area-change, friction, heat transfer, and rotation
- Generating initial (starting) solution
- Robust iterative solution methods

- Coupled heat transfer and work transfer in a rotating duct flow
- Calculation of pressure-rise coefficient of a real exhaust diffuser
- Aerodynamic mixing loss calculation
- Turbine airfoil internal cooling flow modeling with area change, friction, heat transfer, and rotation
- General discussion and additional questions/answers