Информация за научни
конференции и семинари, посветени на математичното моделиране и компютърната
симулация
( юли, 2014)
Elements of Turbulence Modelling
September 17th & 24th 2014
Two Sessions Online Training Course
-
2 hours per session/One session per week
This course has been expanded from
the original one session to two sessions, in order to cover even more content
and allow more time for questions and tutor interaction.
Note: Once you register for the course
using the "order" button (look right), you will receive a
confirmation e-mail. Please click here to
view the FAQ section, or if you need to contact NAFEMS about this course.
Course Overview
The
majority of flows in nature and in engineering applications are turbulent.
Turbulent flow fields are three dimensional, chaotic, diffusive, dissipative,
and random. These flows are characterized by velocity fluctuations in all
directions with infinite number of scales. Exact analytical solution of
Navier-Stokes equations for turbulent flows is not currently possible since
these equations are elliptic, non‐linear, and
coupled. Furthermore, direct numerical simulation (DNS) of turbulent flows is
not currently practical due to significant computational resources required. So
far, DNS approach has only been applied for a limited class of simple low
Reynolds number applications.
Presently, turbulence modelling based on Reynolds-Averaged Navier Stokes (RANS)
equations is the most common and practical approach for turbulence simulation.
RANS are time-averaged modification of Navier-Stokes equations and turbulence
models are semi-empirical mathematical relations that are used to predict the
general effect of turbulence. The objective of turbulence modelling is to
develop equations that will predict the time-averaged velocity, pressure, and
temperature fields without calculating the complete turbulent flow pattern as a
function of time. Unfortunately, there is no single universally accepted
turbulence model that works for all flows and all regimes. Therefore, users
have to use engineering judgement to choose from a number of different
alternatives sine the accuracy and effectiveness of each model varies depending
on the application.
Course Process and Details
This course is completely code independent.
No software is required.
E-learning courses are great alternatives and complements for
continued education as they offer convenience and eliminate the need to travel.
Successful application of turbulence modelling requires engineering
judgement depending on physics of the flow, accuracy, project requirements,
turnaround time, and computational resources available. This course offers the
attendees the practical knowledge for using turbulence modelling for complex
engineering applications. Through a simple and moderately technical approach,
this course describes why we need turbulence modelling and how these models
represent turbulent flows. Various approaches and number of popular turbulence
models will be discussed along with advantages and disadvantages of these
models. Many of the governing and transport equations will be presented for
illustration purposes and may not be dealt in depth in this course. Strong
effort is made for the course to be software neutral. However, examples from
some of the more well known and popular simulation cases and software will be
used throughout the session. Full notes are provided for the attendees.
Students
will join the audio portion of the meetings by utilizing the VoIP (i.e. headset
connected to the computer via headphone and microphone jacks) or by calling
into a standard toll line. If you are interested in additional pricing to
call-in using a toll-free line, please send an email to: e-learning
@ nafems.org .
Who Should Attend?
This course
will be valuable to all engineers aiming to use CFD as a reliable predictive
tool for complex flow problems. The target audience for this course is
practising engineers who wish to learn more about how to choose and apply
effective turbulence modelling in their CFD analysis. Ideally, the
participant should have some knowledge of CFD analysis, but this is not
essential. The material that is presented is independent of any particular
software package, making it ideally suited to current and potential users of
all commercial and non-commercial CFD software systems.
E-learning
classes are ideal for companies with a group of engineers requiring training.
E-learning classes can be provided to suit your needs and timescale. Contact us
to discuss your requirements.
Course Content
- Understanding turbulence
- Turbulence energy cascade & vortex
stretching
- Turbulence scales
- Turbulence generation and destruction
- Discussion on DNS & LES
- Turbulent stresses
- RANS simulation
- Turbulence modelling
- First order models: One-equation &
Two-equations models
- Wall integration & wall function
- Detached eddy simulation
- URANS
- Model comparison: advantages and
disadvantages
- Model Validations
Feedback from former eLearning students:
"This
course did everything right. From organization to presentation to interaction,
this is a good model for what online training should be."
B.T.
"Super!
Doesn't get better than this. Good idea to start having e-Learning
courses."
R.P.
"I'm
really happy not to pay a big fraction of my annual training budget to airlines
and hotels. A BIG plus to e-learning."
V.G.
Special Note(s):
Telephony
surcharges may apply for attendees who are located outside of
Just as with a live face-to-face training course, each
registration only covers one person. If you plan to register a large group
(10+), please send an email to e-learning @ nafems.org in advance for group discounts.
Practical Introduction to FEA
An opportunity to ensure that your organization gets
maximum benefit from using FEA
3-Day Training Course :
Introduction to FEA Analysis
FEA has become widely used and
universally accepted in many industry sectors. FEA is a powerful technique,
able to produce solutions to challenging structural analysis problems. The
technology and computational efficiency of the method, together with the rapid
increases in computer processing power means that today the scope and size of simulations
far exceeds the capabilities of even a few years ago.
However for
those engineers embarking on Finite Element Analysis, or companies adopting the
technique to improve designs or achieve certification of new products, there is
a steep learning curve to overcome.
There are a
bewildering array of element types, solution types, meshing methods and
pre-post processing options that have to be faced. This is before we get down
to the engineering physics behind the problem, with associated classic traps
and errors. What is needed is guidance via a thorough but practical assessment
of the method and how to use it in the real world.
NAFEMS, the
only vendor neutral, not-for-profit organization with the aim of promoting the
effective and reliable use of Finite Element Analysis,, addresses this
requirement by providing this three day example-driven, practical course.
Students
are shown the background to the FEA methodology, via simple real examples with
a minimum of theory. The strength and weaknesses of the various FEA techniques
are shown and discussed. Practical considerations of loadings, boundary
conditions and structural details are shown by numerous examples.
The
assessment, validation and interpretation of Finite Element Analysis,esults are
vital for delivering safe, effective products. A process is shown which
provides confidence in the results and aims to provide conservative, reliable
and qualified results. The attendees join in the activity of building this
process themselves and come away with an embryo Procedural Check List
The course offers excellent guidance on how to assess and plan
the task of carrying out a structural analysis using Finite Element Analysis. A
clear understanding of the objectives of each analysis is vital and a road map
for achieving this is presented.
A review of the tradeoff between available resource and analysis
methodology is given. Interaction is encouraged throughout the course.
Real world examples are given at every stage, drawn from the Tutors wide
practical experience. Questions are very welcome, as this is one of the key
aspects of making this a unique experience for each attendee. Attendee project
examples can often be incorporated into the class as time permits, to benefit
all. Role playing situations include the class acting as a syndicate to
evaluate a Design Failure, critical assessment of an FE Report and the
continuous evolution of the Check List.
The course
is completely code independent, attendees are welcome to bring laptops to take
notes, but they are not required.
A full set
of printed and bound notes will be issued to every attendee.
Who Should Attend?
This course
is aimed at practicing engineers who wish to learn more about how to apply
finite element techniques to their particular problems in the most effective
manner. The material that is presented is independent of any particular
software package, making it ideally suited to current and potential users of
all commercial finite element software systems. This course is a must for all
engineers aiming to use FEA as a reliable predictive tool for thermal,
stiffness and stress analysis.
Companies
moving into FEA technology to improve product designs or assess prototype
failures or speed the design process will benefit from sending key engineers to
this course. If you have sufficient engineers then a tailor made course may be
more suitable. NAFEMS can then work closely with you to cater for your specific
industry sector or analysis type.
The course
is open to both members and non-members of NAFEMS.
Course Program
Registration
will be held on Tuesday morning between
Background
to FEA
- Origins of FEA , leading to today’s process
- Emphasis on limitations of a displacement
solution
- The route from CAD to Mesh to Solver to
Results
- A simple case study – a plate with a hole
- The Analysis Input file
- Simple Element stiffness matrices
- Grid Points , Degrees Of Freedom (DOFs)
Over
view of Element Types
- 1d elements
- 2d elements
- 3d elements
- Solid 3D elements: Hex versus Tets, the
trade off
- Types of meshing and meshing issues
- I-beam example spanning element types
Making
healthy models
- Mis-matched DOF’S and other issues
- Element distortions – effect on accuracy
- Convergence checking
- Solver and Preprocessor checking
- Post processor checking and the dangers of
smoothing
- Stress concentrations and stress
singularities
- Window cutout example
- Building an Analysis Process ‘Cheat Sheet’
Part 1
Constraints
- Constraint methods
- Real world boundary conditions
- Poisons effect
- Minimum support 321 method
- Case Study – bracket analysis
- Linear Contact methods – new technology to
supplement constraints
Loading
Types
- Distributed load, Point Loading
- Real world loading versus FEA
- Bearing load methods
- Nonlinear implications
- Centrifugal and Inertial Loading
- Unit load cases for better understanding
- Case Study – tanker body under cornering and
accident loading
Multi
Point Constraints (MPCs)
- What are they and why use them?
- Different terminologies and usage
- Soft and rigid load and constraint
distribution
Making
Life simpler
- Symmetry
- Anti-symmetry and Axi-symmetry
- Sector Symmetry
- Plane Stress
- Plane strain
- Comparing 1d, 2d, 3d modeling case study of
a pressure vessel
Understanding
the objective of the analysis
- Clear view of scope of problem – how do we
tackle it
- Resource and timescale factors
- FEA Analysis objectives – reservoir case
study
- Class exercise develop an analysis strategy
Looking
at CAD geometry
- Why not use 20 million elements
- Trade offs
- De-featuring
- The reality of CAD models
- Manual methods of meshing
- Building an Analysis Process ‘Cheat Sheet’
Part 2
Engineering
Assessment
- Anticipate the load paths
- Free body Diagrams
- Force Balance
- Review of Stress and Load fundamentals
- Revisiting the I-Beam, comparing theory with
FEA
Checking
the answers
- Ways of checking the results
- What type of stress do I use?
- Review of fundamentals
- Post Processing and More Checking
- Other Checks
- Class Exercise – review an FE report
Other
Topics (dependent on requirements)
- Buckling
- Introduction to Non-linear Analysis
- Introduction to Dynamics and Normal Modes
Analysis
- Introduction to Composite Analysis
Conclusions
- Review of the Class exercise – developed
Analysis Process ‘Cheat Sheet’
- Debrief
Venue
Macdonald Townhouse Hotel
Tel 0844 855 9136
http://www.macdonaldhotels.co.uk/our-hotels/macdonald-townhouse-hotel/
Situated right in the beating heart
of
Road: 10 minutes from M60
Rail: 5 minutes to
Air: 9 miles from
Accommodation
We have secured a
limited number of rooms at the venue hotel, at a special rate of
£95, including VAT on a bed & breakfast basis. Please contact the
hotel directly, advising reservations that you are attending a NAFEMS course,
to book rooms at the discounted rate. This reduced rate is applicable to
NAFEMS delegates until six
weeks prior to
course date.