Fluent Software Training UGM 2001
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© Fluent Inc. 5/4/2020
Fluent Software Training UGM 2001
Motivation
Flows involving rotating domains occur frequently in engineering Examples
Introduction to the SRF Model
Many problems which involve rotating components can be modeled using a single rotating reference frame.
Why use a rotating reference frame?
stationary and/or rotating surfaces ducts walls, bores and cavities, seal teeth surfaces, etc.
Rotation(s) assumed to be steady
accelerating reference frames can be modeled with source terms (not considered here)
compressors and turbines fans and pumps rotating cavities, seals, and bearings mixing equipment fluid coupling devices and torque converters air motors marine and aircraft propellers and many more…
Mixed Flow
Flow through the machine is somewhere between axial and centrifugal Example: mixed flow compressor
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Fluent Software Training UGM 2001
Other considerations…
laminar/turbulent flow, other physics (e.g. multiphase flow, heat transfer) level of interaction between moving/stationary co rotating machinery problems using Fluent
Model setup Solution process (steady-state and unsteady)
Answer your questions!
Rotating tanks, seals, cavities, and other devices disk cavities and labyrinth seals in gas turbine engines electric motor cooling passages disk drives rotating tires on automotive vehicles
Examples of Rotating Machinery
steam turbine
HVAC blower unit
hydro turbine
tube axial fan
automotive water pump
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gas turbine engine
© Fluent Inc. 5/4/2020
Fluent Software Training UGM 2001
Multiple Rotating Frame (MRF)
Selected regions of the domain are referred to rotating reference frames Ignore interaction effects steady-state
Mixing Plane (MPM)
Classification of Turbomachinery
Axial machines
Flow through the machine is (in general) aligned with the axis of rotation Examples: propellers, axial fans/compressors/turbines, swirlers
Centrifugal machines
Flow through the machine is (in general) perpendicular to the axis of rotation Examples: liquid pumps, centrifugal fans/compressors, radial turbines
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© Fluent Inc. 5/4/2020
Fluent Software Training UGM 2001
Types of Rotating Machinery
In this course, we will classify rotating machinery as follows:
Turbomachinery - machines which add work to or extract work from a fluid compressors, fans, pumps - add work to achieve a pressure rise in the fluid turbines, windmills - extract work from fluid to drive other machines
Influence of neighboring regions accounted for through use of a mixing plane model at rotating/stationary domain interfaces
Ignore circumferential non-uniformities in the flow steady-state
Goals of the Training
Provide an introduction to rotating machinery modeling Examine the four major classes of rotating machinery problems
Single rotating reference frame (SRF) Multiple rotating reference frame (MRF) Mixing plane Sliding mesh
Mixing equipment - machines which are designed to mix fluid (and possibly solid) materials for use in a chemical processing application industrial mixing tanks
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© Fluent Inc. 5/4/2020
Fluent Software Training UGM 2001
Single Reference Frame (SRF) Modeling
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© Fluent Inc. 5/4/2020
Fluent Software Training UGM 2001
Computational Fluid Dynamics (CFD) today plays a central role in the design and analysis of rotating machinery
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© Fluent Inc. 5/4/2020
Fluent Software Training UGM 2001
Well-posed boundary conditions
flowrates, pressures, temperatures, other scalars at inlet/outlet boundaries wall motion, thermal, other BCs at walls
All of these applications involve rotating surfaces and domains (and thus may use a rotating reference frame for modeling)
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© Fluent Inc. 5/4/2020
Fluent Software Training UGM 2001
We will discuss issues related to SRF modeling in this section, but many concepts (e.g. solver settings, physical models, etc.) will also apply to MRF, mixing plane, and sliding mesh modeling.
Basic Problem Statement
We wish to solve for the flow through a domain which contains
rotating components propeller, compressor/turbine blade, radial impeller, etc.
Fluent Software Training UGM 2001
Introduction to Rotating Machinery Analysis Using Fluent