All Things ANSYS 034 – Celebrating 25 Years of ANSYS Simulation: Changes In The Last Quarter Century & Where The Future Will Take Us

 

Published on: April 8th, 2019
With: Eric Miller, Ted Harris, Tom Chadwick, Sina Ghods, & Alex Grishin
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s Ted Harris, Tom Chadwick, Sina Ghods, and Alex Grishin, for a round-table discussion on their experience and history with simulation, including what has changed since they started using it and what they’re most impressed and excited by, followed by some prediction and discussion on what the future may hold for the world of numerical simulation.

Thank you again for those of you who have made the past 25 years something to remember, and to those of you who have come to know PADT more recently, we look forward to what the next 25 will bring.

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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@ANSYS #ANSYS

All Things ANSYS 030 – Updates Available in ANSYS Fluent 2019 R1

 

Published on: February 13th, 2019
With: Eric Miller, Tom Chadwick, & Sina Ghods
Description:  

In this episode your host and Co-Founder of PADT, Eric Miller is joined by Sina Ghods, and Tom Chadwick from the Simulation Support Team for a discussion on their favorite updates available in the latest release of ANSYS Fluent so far, followed by an update on news and upcoming events pertaining to PADT and ANSYS Simulation.

Want to learn more about what to expect in ANSYS Fluent 2019 R1? Check out PADT’s webinar covering everything you need to know about the tool’s latest update.

Watch here: https://bit.ly/2SJBFC4

If you have any questions, comments, or would like to suggest a topic for the next episode, shoot us an email at podcast@padtinc.com we would love to hear from you!

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@ANSYS #ANSYS

Gone Skiing: Aerodynamics – Does It Matter Which Way Your Skis Are Pointing On Your Roof Rack?

I was on the gondola up at Keystone for night-skiing a week ago, after a long day at Beaver Creek, because the last thing I am going to do at 3:00 pm is try to make it back to Denver, as everyone knows it’s hardly more than a parking lot at that point. As it gets later, there’s nothing like a solo gondola ride, however, a solo ride would stop this story right about now.

On the gondola, I overheard a conversation where one gentleman was discussing how he was unable to open the hatch of his vehicle when his skis are in his roof rack. That’s fair, I know older WRX wagons with the spoiler would not be able to open with skis on the roof no matter what, so I figured that was the case. It turns out, that was NOT the case. The reason his hatch would not open was that he orients the skis with the tails forward because it is ‘more aerodynamic’ that way… I was skeptical, but held my tongue, knowing that I had the tools at my disposal to investigate!

I decided to make a model that would allow me to simulate various conditions to get to the bottom of this. My initial hypothesis is that the addition of the ski rack and crossbars is what has the largest effect on aerodynamics, and orientation of the skis probably has a negligible effect after that. As a side note, I am solely concerned with aerodynamics in this case, and am not worrying about the amount of the ski’s base material that is exposed for a given orientation. I am of the mindset that tree trunks and hidden rocks on the mountain are more of a danger to your bases than small rocks on the highway anyway. If you are waiting to comment, “Just get a roof box!”, I understand as I own both a box and a rack at this point, and they both have their advantages, and I will not be exploring the aerodynamics of a box…

…yet…

I was able to start by finding some faceted geometry of a Subaru Forester online (I’m from Colorado, can you tell?) and was able to import that into ANSYS Spaceclaim. Once in Spaceclaim, I was able to edit the faceted geometry to get nice exterior panel surfaces, which I then combined to get a single clean faceted exterior for the car.


Faceted Forester Geometry (Equipped with factory side rails)

After that, I used Spaceclaim to generate the remainder of the rack and skis, including crossbars, a ski rack, and a pair of skis (Complete with the most detailed bindings you have ever seen!). I made a combined part of the crossbars, rack, and skis for each one of my orientations, as this allows me to report the forces on each combined part during the simulation.


Added CAD geometry for the crossbars, ski rack, and a pair of skis

For the simulation, I used ANSYS Discovery Live, the newest tool from ANSYS that allows for instant and interactive design exploration. This tool lets me actively add my CAD geometry and shows results in realtime. I was able to start with just the car and then add and swap my ski/rack geometry with simple button clicks. With traditional simulation tools, I would have needed to create a mesh for each one of these cases, analyze them one at a time, and the post-process and compare results after the fact. After launching Discover Live, it’s as easy as selecting the type on analysis I want to run.

The various types of solutions that can be done in ANSYS Discovery Live. For the purpose of this blog, I am using ‘Wind Tunnel’

Once I have selected ‘Wind Tunnel’ for my solution, I can select my geometry, and then am prompted for the direction of flow, as well as selecting the ‘floor’ of my domain. Once that is done, results show up on the screen instantly. I only needed to modify the flow velocity to ~65 mph. I am most interested in the force on the faces of the combined crossbars, rack, and skis in each orientation, so I created Calculations for each one, which is done by simply selecting the part and using the popup toolbar to create the graph.

Popup toolbar allows for the quick creation of solution calculations

I was already off and running. I ran each one of the cases until the force plot had become steady.

Car Only
Skis Tips Forward Orientation

Skis Tails Forward Orientation

Seeing that the force results for the Tips Forward vs. Tails Forward cases were very similar, I decided I should also run a ‘Bases Up’ Orientation, even though I STRONGLY advise against this, as UV wrecks the base material of your skis/snowboard.

Ski Bases Up and Tips Forward Orientation

In addition to the contour plot shown in the images above, you can also use emitters to show streamlines and particle flow, which also give some pretty neat visualizations.

Streamlines shown on the Tips Forward orientation

Particle Emitter shown on the Tips Forward orientation

The graph plots show values for the Total Y Force for Tips Foward, Tails Forward, and Bases Up orientations to be 37.7 N, 39.1 N, and 37.1 N, respectively. Using Discovery Live, I was able to quickly run all 3 of these simulations, showing that there is not a major difference in the forces on the ski rack between the three orientations. So, put the skis on the roof in the direction that makes life easiest for you, and keep those bad boys paired to protect your bases from the sun, because splitting them isn’t going to help with aerodynamics anyway!

Next steps would be taking a specific case and running in 2D, then 3D, in ANSYS Fluent.

Fluent Updates in ANSYS 2019 R1 – Webinar

Computational Fluid Dynamics (CFD) is a tool with amazing flexibility, accuracy and breadth of application. Serious CFD, the kind that provides insights to help you optimize your designs, could be out of reach unless you choose your software carefully.

Experienced engineers need to go further and faster with well-validated CFD results across a wide range of applications, and with ANSYS Fluent users are to do just that; delivering reliable and accurate results.

Join Padt’s CFD Team Lead Engineer, Clinton Smith for a look at what new capabilities are available for the latest version of Fluent, in ANSYS 2019 R1.

This presentation will be focused on eight main sections, including:

  • User Interface
  • Preprocessing
  • Workflow Enhancements
  • Solver Enhancements
  • Transient Enhancements
  • Applications
  • Physics
  • Optimization

Learn how Fluent is the most effective tool for simulating fluid flow, various types of erosion, and much more.

Register Here

If this is your first time registering for one of our Bright Talk webinars, simply click the link and fill out the attached form. We promise that the information you provide will only be shared with those promoting the event (PADT).

You will only have to do this once! For all future webinars, you can simply click the link, add the reminder to your calendar and you’re good to go!

Meshing Enhancements in ANSYS 19.2 – Webinar

Don’t miss this informative presentation – Secure your spot today!

If this is your first time registering for one of our Bright Talk webinars, simply click the link and fill out the attached form. We promise that the information you provide will only be shared with those promoting the event (PADT).

You will only have to do this once! For all future webinars, you can simply click the link, add the reminder to your calendar and you’re good to go!

Press Release: On-Demand High Performance Cloud Computing for Today’s Most Demanding Workflows Offered by PADT in Partnership with Nimbix

Sometimes if you look hard enough, you find what you need.  Ever since people started talking about running large simulation models in the “cloud” our engineers here at PADT have been looking for a good solution. We even offered our own service, and although it was fast and easy to use, we could not make it big enough. Then along comes Nimbix. And they nailed it.

First we asked, are they running on real HPC hardware, not souped up web servers with virtual machines on them? Yes. We found bare metal hardware striped down to fighting weight that is optimized for running simulation.

Then we asked, Is it easy to use or do I have to jump through hoops to just get a job running?  Indeed it was easy and powerful. We just wanted to submit jobs and found that the JARVICE™ interface does so much more to configure, setup, submit, and monitor even the most complex parallel solves.

OK, this looked good, but the real test is do we have access to whole machines or is this just a timesharing system with a great interface?  Turns out it is not.  It is true cloud-based high-performance computing.

We think we found what we were looking for, but we have been burned before.  So we did what any simulation engineer would do, we pounded on it with massive ANSYS FLUENT, Mechanical, and HFSS runs.  We knew it was real when we were monitoring a CFD run on a mobile phone from a coffee shop in-between customer visits.

We liked it so much that we asked if we could partner with them to offer it to our customers. And that is where we are today with this press release.

PADT is proud to announce that we are able to provide our customers with on-demand HPC resources that are fast, easy to use, and cost-effective.  If you are a simulation user who needs to run large jobs, access surge capacity, or just solve faster, Nimbix is the answer. And PADT is here to help determine the right configuration and guide you through the process.

Please read the press release below for more details on what we are doing.

This video explains Nimbix well:

You can also learn more about our experience by watching a free webinar we recorded where we shared our experience using this service: www.brighttalk.com/webcast/15747/330189

Please find the official press release on this new partnership below and here in PDF and HTML

If you have any questions about high-performance computing for simulation, either with local hardware or compute resources in the cloud, reach out to info@padtinc.com or call 480.813.4884.

Press Release:

On-Demand High Performance Cloud Computing for Today’s
Most Demanding Workflows Offered by PADT in Partnership with Nimbix

Nimbix Cloud Provides Access to ANSYS Applications Through Cloud Supercomputing, Removing the Requirement of Expensive Infrastructure and Hardware

TEMPE, Ariz., July 26, 2018 ─ Understanding the need for easy, affordable and reliable access to supercomputing capabilities, PADT has partnered with Nimbix to provide High-Performance Computing (HPC) in the cloud. The Nimbix Cloud is the industry’s first true Software-as-a-Service (SaaS) supercomputing cloud and will provide PADT’s customers with on-demand, mobile access to more than 15 ANSYS applications without needing expensive hardware and complex infrastructure to support it. Current ANSYS applications available with Nimbix are listed here.

“As long-time simulation users, PADT has always wanted to leverage the cloud for running ANSYS models, but no one could support it before Nimbix,” said Bob Calvin, manager, Simulation Solutions, PADT. “The Nimbix Cloud gives our customers a flexible way to run large models from anywhere and accommodate surge capacity when it is needed.”

The Nimbix Cloud is powered by the JARVICE™ platform, which Nimbix purpose-built from the ground-up to accommodate the most demanding workflows by providing superior performance, capabilities, and ease of use. PADT customers can manage start-up, execution, completion and notifications on full-featured ANSYS applications in the cloud, and send their data from any device including desktop, tablet and smartphones.

“With its global recognition as a provider of numerical simulation and product development, PADT is the ideal partner to leverage the JARVICE platform internally and as an offering to its customers,” said Chuck Kelly, senior vice president, Sales, Nimbix. “Nimbix high-performance computing in the cloud provides a competitive advantage by allowing users to more easily solve complex design problems and then send the data anywhere to turn results into actionable insights.”

“We use Nimbix frequently at PADT because of its reliability and performance when running ANSYS software in the cloud,” said Manoj Mahendran, lead application engineer, PADT. “The platform has allowed us to easily check and submit simulation test results off-site and on-the-go, providing more flexibility to our simulation teams.”

Nimbix Cloud is available today, and PADT invites customers to learn more about the challenges, tools, and mindset needed to run simulation in the cloud, and how the Nimbix platform can be an effective solution, in a webinar on August 8, 2018. To register for the webinar, please visit https://www.brighttalk.com/webcast/15747/330189.

About Phoenix Analysis and Design Technologies

Phoenix Analysis and Design Technologies, Inc. (PADT) is an engineering product and services company that focuses on helping customers who develop physical products by providing Numerical Simulation, Product Development, and 3D Printing solutions. PADT’s worldwide reputation for technical excellence and experienced staff is based on its proven record of building long-term win-win partnerships with vendors and customers. Since its establishment in 1994, companies have relied on PADT because “We Make Innovation Work.” With over 80 employees, PADT services customers from its headquarters at the Arizona State University Research Park in Tempe, Arizona, and from offices in Torrance, California, Littleton, Colorado, Albuquerque, New Mexico, Austin, Texas, and Murray, Utah, as well as through staff members located around the country. More information on PADT can be found at www.PADTINC.com.

# # #

Media Contact
Alec Robertson
TechTHiNQ on behalf of PADT
585-281-6399
alec.robertson@techthinq.com
PADT Contact
Eric Miller
PADT, Inc.
Principal & Co-Owner
480.813.4884
eric.miller@padtinc.com

 

All Things ANSYS 012 – Live From New Mexico: A Look at What’s New in ANSYS 19

 

Published on: January 30, 2018
With: David Mastel, Joe Woodword, Manoj Mahendran, Matt Sutton, Michael Griesi, Tom Chadwick, Ted Harris, Eric Miller
Description: In this episode your host and Co-Founder of PADT, Eric Miller is joined by PADT’s David Mastel, Joe Woodword, Manoj Mahendran, Matt Sutton, Michael Griesi, Tom Chadwick, and Ted Harris, for a discussion on what is new and improved in the recently released ANSYS 19.
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Getting to Know PADT: Simulation Services

This is the fourth installment in our review of all the different products and services PADT offers our customers. As we add more, they will be available here.  As always, if you have any questions don’t hesitate to reach out to info@padtinc.com or give us a call at 1-800-293-PADT.

The A in PADT actually stands for Analysis.  Back in 1994 when the company was started, computer modeling for mechanical engineering was called Analysis. It was such an important part of what we wanted to achieve that we put it in the name.  Unfortunately, Analysis was a bit to generic so the industry switched to Numerical Simulation, or simply simulation. In the 23 years since we started, analysis… sorry, simulation, has been not just a foundation for what PADT does for our customers, it has become a defacto tool in product development.  Through it all there has been a dedicated group here that is focused on providing the best simulation as a service to customers around the world.

Driving Designs with Simulation

Many companies know about PADT with regards to simulation because we are an ANSYS Elite Channel Partner – selling and supporting the entire suite of ANSYS simulation tools in the Southwestern US. The success of simulation in the design and development of physical products is a direct result of the fact that these fantastic tools from ANSYS can be used to drive the design of products.  This can be done in-house by companies designing the products, or outsourced to experts. And that is where PADT has come in for hundreds of customers around the world.  The expertise we use to support and train on ANSYS products derives directly from our real world experience providing CFD, structural, thermal, electromagnetic, and multiphysics simulations to help those customers drive their product development.

For those not familiar with simulation, or who only use the basic tools embedded in CAD software as a quick check, understanding why it is so important hinges on understand what it really is. Numerical Simulation is a methodology where a physical product is converted into a computer model that represents its physical behavior.  This behavior can be many different physics: stresses, vibration, fluid flow, temperature flow, high frequency electromagnetic radiation, sloshing of liquids, deformation during impact, piezoelectric response, heating from static electromagnetic waves, cooling from air flow. The list goes on and on. Pretty much anything you studied in physics can be modeled using a numerical simulation.

The process of doing the simulation consists of taking the physical object and breaking it into discrete chunks, often very small relative to the size of the object, so that equations can easily be written for each chunk that describes the physical behavior of that chunk relative to the chunks around it.  Imagine writing equations for the fluid flow in a complicated valve housing, very hard to do. But if you break it up into about one million small polyhedrons, you can write an equation for flow in and out of each polyhedron. These equations are then assembled into a giant matrix and solved using linear algebra.  That is why we need such large computers.  We mostly use the world’s leading software for this, from ANSYS, Inc.

More than Building and Running Models

Knowing how to build and run finite element and CFD models is key to providing simulation as a service. PADT’s team averages over 18 years of experience and few people come close to their knowledge on geometry preparation, meshing, setting up loads and boundary conditions, leveraging the advantages of each solver, and post processing. That is a good starting point. But what really sets PADT apart is the understanding of how the simulation fits into product development, and how the information gathered from simulation can and should be used.  Instead of providing a number or a plot, PADT’s experienced engineers deliver insight into the behavior of the products being simulated.

How each project is conducted is also something that customers keep coming back for.  Nothing is ever “thrown over the wall” our passed through a “black box.” From quote through delivery of final report, PADT’s engineers work closely with the customer’s engineers to understand requirements, get to the heart of what the customer is looking for, and deliver useful and actionable information.  And if you have your own in-house simulation team, we will work closely with them to help them understand what we did so they can add it to their capabilities. In fact, one of the most popular simulation services offered by PADT is automation of the simulation process with software tools written on top of ANSYS products.  This is a fantastic way to leverage PADT’s experience and knowledge to make your engineers more efficient and capable.

Unparalleled Breadth and Depth

Based on feedback from our customers, the other area where PADT really stands out is in the incredible breadth and depth of capability offered.  Whereas most service providers specialize in one type of simulation or a single industry, more than twenty years of delivering high-end simulation to evaluate hundreds of products has given PADT’s team a unique and special level of understanding and expertise. From fluid flow in aerospace cooling systems to electromagnetics for an antenna in a smart toy, a strong theoretical understanding is combined with knowledge about the software tools to apply the right approach to each unique problem.

No where is this breadth and depth exemplified than with PADT’s relationship with ANSYS, Inc. Since the company was founded, PADT engineers have worked closely with ANSYS development and product management to understand these powerful tools better and to offer their advice on how to make them better.  And each time ANSYS, Inc. develops or acquires a new capability, that same team steps up and digs deep into the functionality that has been added. And when necessary, adding new engineers to the team to offer our customers the same expert access to these new tools.

 

The best way to understand why hundreds of companies, many of them large corporations that are leaders in their industry, come to PADT from around the world for their simulation services needs is to talk to us about your simulation services needs. Regardless of the industry or the physics, our team is ready to help you drive your product development with simulation. Contact us now to start the discussion.

 

Combining ANSYS Simulation with HPC

Engineering simulation has become much more prevalent in engineering organizations than it was even 5 years ago.  Commercial tools have gotten significantly easier to use whether you are looking at tools embedded within CAD programs or the standalone flagship analysis tools.  The driving force behind these changes are to ultimately let engineers and companies understand their design quicker with more fidelity than before.

Engineering simulation is one of those cliché items where everyone says “We want more!”  Engineers want to analyze bigger problems, more complex problems and even do large scale design of experiments with hundreds of design variations – and they want these results instantaneously.   They want to be able to quickly understand their designs and design trends and be able to make changes accordingly so then can get their products optimized and to the market quicker.

ANSYS, Inc. spends a significant amount of R&D in helping customers get their results quicker and a large component of that development is High Performance Computing, or HPC.  This technology allows engineers to solve their structural, fluid and/or electromagnetic analyses across multiple processors and even across multiple computing machines.  Engineers can leverage HPC on laptops, workstations, clusters and even full data centers.

PADT is fortunate to be working with Nimbix, a High Performance Computing Platform that easily allowed us to quickly iterate through different models with various cores specified.  It was seamless, easy to use, and FAST!

Let’s take a look at four problems: Rubber Seal FEA, Large Tractor Axle Model, Quadrocopter CFD model and a Large Exhaust CFD model.  These problems cover a nice spectrum of analysis size and complexity. The CAD files are included in the link below.

Click here to download geometry files that were used in the following benchmarks

TRACTOR AXLE FEA

This model has several parts all with contact defined and has 51 bolts that have pretension defined.  A very large but not overly complex FEA problem.  As you can see from the results, even by utilizing 8 cores you can triple your analysis throughput for a work day.  This leads to more designs being analyzed and validated which gives engineers the results they need quicker.

SUMMARY

  • 58 Parts
  • 51 x Bolts with Pretension
  • Gaskets
  • 928K Elements, 1.6M Nodes

Cores

Elapsed Time
[s]

Estimated Models Per 8 [hours]

2

14,525

2

4

9,710

3

8

5,233

6

16 4,009

7

 

RUBBER SEAL FEA

The rubber seal is actually a relatively small size problem, but quite complex.  Not only does it need full hyperelastic material properties defined with large strain effects included, it also includes a leakage test.  This will pressurize any exposed areas of the seal.  This will of course cause some deformation which will lead to more leaked surfaces and so on.  It basically because a pressure advancing solution.

From the results, again you can see the number of models that can be analyzed in the same time frame is signifcantly more.  This model was already under an hour, even with the large nonlinearity, and with HPC it was down to less than half an hour.

SUMMARY

  • 6 Parts
  • Mooney Rivlin Hyperelastic Material
  • Seal Leakage with Advancing Pressure Load
  • Frictional Contact
  • Large Deformation
  • 42K Elements, 58K Nodes

Cores

Elapsed Time
[s]
Estimated Models Per 8 [hours]

2

3,353

9

4

2,489

12

8 1,795

16

 


QUADROCOPTER DRONE CFD

The drone model is a half symmetry model that includes 2 rotating domains to account for the propellers.  This was ran as a steady state simulation using ANSYS Fluent.  Simply utilizing 8 cores will let you solve 3 designs versus 1.

SUMMARY

  • Multiple Rotating Domains
  • 2M Elements, 1.4M Nodes

Cores

Elapsed Time
[hours]
Speedup

2

2.1

1

4

1.2

1.8

6

0.8

2.6

8 0.7

3

 

EXHAUST CFD

The exhaust model is a huge model with 33 million elements with several complicated flow passages and turbulence.  This is a model that would take over a week to run using 1 core but with HPC on a decent workstation you can get that down to 1 day.  Leveraging more HPC hardware resources such as a cluster or using a cloud computing platform like Nimbix will see that drop to 3 hours.  Imagine getting results that used to take over 1 week that now will only take a few hours.  You’ll notice that this model scaled linearly up to 128 cores.  In many CFD simulations the more hardware resources and HPC technology you throw at it, the faster it will run.

SUMMARY

  • K-omega SST Turbulence
  • Multi-Domain
  • 33M Elements, 7M Nodes

Cores

Elapsed Time
[hours]
Speedup

16

26.8

1

32

13.0

2.1

64

6.8

3.9

96

4.3

6.2

128 3.3

8.2

As seen from the results leveraging HPC technology can be hugely advantageous.  Many simulation tools out there do not fully leverage solving on multiple computing machines or even multiple cores.  ANSYS does and the value is easily a given.  HPC makes large complex simulation more practical as a part of the design process timeline.  It allows for greater throughput of design investigations leading to better fidelity and more information to the engineer to develop an optimized part quicker.

If you’re interested in learning more about how ANSYS leverages HPC or if you’d like to know more about NIMIBX, the cloud computing platform that PADT leverages, please reach out to me at manoj@padtinc.com

 

When the going gets tough, the tough use ANSYS for CFD Meshing

If you do CFD simulations then you know the struggle that is involved in meshing. It is a fine balance of accuracy, speed, and ease of set up. If you have complex geometry, large assemblies, or any difficulty meshing then this blog article is for you.

Why should I spend time making a good mesh?

The mesh is arguably one of the most important parts of any simulation set up. A good mesh can solve significantly faster and provide more accurate results. Conversely, a poor mesh can make the simulation have inaccurate results and be slow to converge or not converge at all. If you have done any simulation then you know that hitting the solve button can feel like rolling the dice if you don’t have a robust meshing tool.

When is it going to matter?

A good mesh is going to matter on a Friday afternoon when you need to get the simulation started before you leave for the weekend because it takes two days to run and you need to deliver results on Monday but you are up against the clock because you have to get to your kid’s soccer game by 5pm and the mesh keeps crashing.

A poor mesh can do more than just reorganizing you’re social agenda. A poor mesh can drastically change results like pressure drop in an internal flow passage or drag over a body. If you go into that meeting on Monday and tell your boss that the new design is going to perform 10% better than the previous design – you need to be confident that the design is 10% better not 10% worse.

What should I do when I need to create a good mesh?

If you’re the poor soul reading this on a Friday afternoon because you are trying to frantically fix you’re mesh so you can get your simulation running before the weekend – I pity you. Continue reading for my proprietary step by step approach titled “How to get you’re CFD mesh back on track!” (Patent pending).

Step 1) Know your tools

ANSYS has been developing its meshing technology since the beginning of time (not really but almost) – it’s no surprise that its meshing algorithms are the best in the business. In ANSYS you have a large number of tools at your disposal, know how to use them.

The first tool in your toolbox is the ANSYS automatic meshing technology. It is able to predictively apply settings for your part to get the most accurate automatic mesh possible. It has gotten so good that the automatic mesh is a great place to start for any preliminary simulations. If you want to get into the details, ANSYS meshing has two main groups of mesh settings – Global Meshing Parameters and Local Meshing Parameters. Global mesh parameters are great for getting a good mesh on the entire model without going into detailed mesh settings for each part.

But when you do have to add detailed meshing settings on a part by part basis then local mesh settings won’t let you down.

Step 2) Know your physics

What is your primary result of interest? Drag? Pressure drop? Max velocity? Stagnation? If you can quantify what you are most interested in then you can work to refine the mesh in that region so as to capture the physics accurately. ANSYS allows you set local sizing parameters on bodies, faces, lines, and regions which allow you to get the most accurate mesh possible but without having to use a fine mesh on the entire part.

Step 3) Know your mesh quality statistics

Mesh quality statistics can be a good way to gauge the health of your mesh. They are not a foolproof method for creating a mesh that will be accurate but you will be able to get an idea of how well it will converge. In ANSYS meshing there is a number of mesh quality statistics at your fingertips. A quick and easy way to check your mesh is to look at the Minimum Orthogonal Quality statistic and make sure it is greater than 0.1 and Maximum Skewness is less than 0.95.

Step 4) Know your uncertainty

Every test, simulation, design, process etc… has uncertainty. The goal of engineering is to reduce that uncertainty. In simulation meshing is always a source of uncertainty but it can be minimized by creating high quality meshes that accurately model the actual physical process. To reduce the uncertainty in meshing we can perform what is called a mesh refinement study. Using the concept of limits we can say that in the limit of the mesh elements getting infinitely small than the results will asymptotically approach the exact solution. In the graph below it can be seen that as the number of elements in the model are increased from 500 – 1.5million the result of interest approached the dotted line which we can assume is close to the exact solution.

By completing a mesh refinement study as shown above you can be confident that the mesh you have created is accurately capturing the physics you are modeling because you can quantify the uncertainty.

If you currently just skip over the meshing part of your CFD analysis thinking that it’s good enough or if your current meshing tool doesn’t give you any more details than just a green check mark or a red X then it’s time dig into the details of meshing and start creating high quality meshes that you can count on.

For more info about advanced meshing techniques in ANSYS – see this PDF presentation that is a compilation of ANSYS training material on the meshing subject.

Advanced Techniques in ANSYS Meshing_Blog

If you still haven’t figured out how to get your mesh to solve and its 5pm on Friday see below*

*Common pitfalls and mistakes for CFD meshing:

  • Choose your turbulence model wisely and make sure your mesh meets the quality metrics for that model.
  • Make sure you don’t have boundary conditions near an area of flow recirculation. If you are getting reverse flows at the boundary then you need to move your boundary conditions further away from the feature that’s causing the flow to swirl in and out of the boundary.

Phoenix Business Journal: ​How do you get value out of Big Data? Simulation!

It’s all the rage. “Big Data!” fixes everything. There is a lot of hype around the value of knowing so much about so many things. The problem is very few people have figured out what to do with that data.  But leading technology companies like GE are using a proven tool to get value from all that great data.  In “How do you get value out of Big Data? Simulation!” I look at how numerical simulation can be used to create digital twins of what your products are doing in the real world, delivering huge benefits today.

ANSYS 17.2 Executable Paths on Linux


ansys-linux-penguin-1When running on a machine with a Linux operating system, it is not uncommon for users to want to run from the command line or with a shell script. To do this you need to know where the actual executable files are located. Based on a request from a customer, we have tried to coalesce the major ANSYS product executables that can be run via command line on Linux into a single list:

ANSYS Workbench (Includes ANSYS Mechanical, Fluent, CFX, Polyflow, Icepak, Autodyn, Composite PrepPost, DesignXplorer, DesignModeler, etc.):

/ansys_inc/v172/Framework/bin/Linux64/runwb2

ANSYS Mechanical APDL, a.k.a. ANSYS ‘classic’:

/ansys_inc/v172/ansys/bin/launcher172 (brings up the MAPDL launcher menu)
/ansys_inc/v172/ansys/bin/mapdl (launches ANSYS MAPDL)

CFX Standalone:

/ansys_inc/v172/CFX/bin/cfx5

Autodyn Standalone:

/ansys_inc/v172/autodyn/bin/autodyn172

Note: A required argument for Autodyn is –I {ident-name}

Fluent Standalone (Fluent Launcher):

/ansys_inc/v172/fluent/bin/fluent

Icepak Standalone:

/ansys_inc/v172/Icepak/bin/icepak

Polyflow Standalone:

/ansys_inc/v172/polyflow/bin/polyflow/polyflow < my.dat

Chemkin:

/ansys_inc/v172/reaction/chemkinpro.linuxx8664/bin/chemkinpro_setup.ksh

Forte:

/ansys_inc/v172/reaction/forte.linuxx8664/bin/forte.sh

TGRID:

/ansys_inc/v172/tgrid/bin/tgrid

ANSYS Electronics Desktop (for Ansoft tools, e.g. Maxwell, HFSS)

/ansys_inc/v172/AnsysEM/AnsysEM17.2/Linux64/ansysedt

SIWave:

/ansys_inc/v172/AnsysEM/AnsysEM17.2/Linux64/siwave

Simulation Driven Product Development with Free Form Fabrication

am-topo-prezo-titleJoining Two of PADT’s Favorite Things: Simulation and 3D Printing

Recent advances in Additive Manufacturing (3D Printing) have removed barriers to manufacturing certain geometry because of constraints in traditional manufacturing methods. Although you can make almost any shape, how do you figure out what shape to make. Using ANSYS products you can apply topological optimization to come up with a free-form shape that best meets your needs, and that can be made with Additive Manufacturing.

A few months ago we presented some background information on how to drive the design of this type of part using ANSYS tools to a few of our customers.  It was a well received so we cleaned it up a bit (no guarantee there all the typos are gone) and recorded the presentation.  Here it is on YouTube

Let us know what you think and if you have any questions or comments, please contact us.

Video Tips: Fluid Volume Extraction

This video shows a really quick and easy way to extract a fluid domain from a structural model without having to do any Boolean subtract operations.

CoresOnDemand: Helping Engineers Do Their Magic

CoresOnDemand-Logo-120hEngineers Do Magic

In the world of simulation there are two facts of life. First, the deadline of “yesterday would be good” is not too uncommon. Funding deadlines, product roll-out dates, as well as unexpected project requirements are all reliable sources for last minute changes. Engineers are required to do quality work and deliver reliable results in limited time and resources. In essence perform sorcery.

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Second, the size and complexity of models can vary wildly. Anything from fasteners and gaskets to complete systems or structures can be in the pipeline. Engineers can be looking at any combination of hundreds of variables that impact the resources required for a successful simulation.

Required CPU cores, RAM per core, interconnect speeds, available disk space, operating system and ANSYS version all vary depending on the model files, simulation type, size, run-time and target date for the results.

Engineers usually do magic. But sometimes limited time or resources that are out of reach can delay on-time delivery of project tasks.

At PADT, We Can Help

PADT Inc. has been nostrils deep in engineering services and simulation products for over 20 years. We know engineering, we know how to simulate engineering and we know ANSYS very well. To address the challenges our customers are facing, in 2015 PADT introduced CoresOnDemand to the engineering community.

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CoresOnDemand offers the combination of our proven CUBE cluster, ANSYS simulation tools and the PADT experience and support as an on demand simulation resource. By focusing on the specific needs of ANSYS users, CoresOnDemand was built to deliver performance and flexibility for the full range of applications. Specifics about the clusters and their configurations can be found at CoresOnDemand.com.

CoresOnDemand is a high performance computing environment purpose built to help customers address numerical simulation needs that require compute power that isn’t available or that is needed on a temporary basis.

Call Us We’re Nice

CoresOnDemand is a new service in the world of on-demand computing. Prospective customers just need to give us a call or send us an inquiry here to get all of their questions answered. The engineers behind CoresOnDemand have a deep understanding of the ANSYS tools and distributed computing and are able to asses and properly size a compute environment that matches the needed resources.

Call us we’re nice!

Two Halves of the Nutshell

The process for executing a lease on a CoresOnDemand cluster is quite straight forward. There are two parts to a lease:

PART 1: How many cores & how long is the lease for?

By working with the PADT engineers – and possibly benchmarking their models – customers can set a realistic estimate on how many cores are required and how long their models need to run on the CoresOnDemand clusters. Normally, leases are in one-week blocks with incentives for longer or regular lease requirements.

Clusters are leased in one-week blocks, but we’re flexible.

Part 2: How will ANSYS be licensed?

An ANSYS license is required in order to run on the CoresOnDemand environment.  A license lease can be generated by contacting any ANSYS channel partner. PADT can generate license leases in Arizona, Colorado, New Mexico, Utah & Nevada. Licenses can also be borrowed from the customer’s existing license pool.

An ANSYS license may be leased from an ANSYS channel partner or borrowed from customer’s existing license pool.

Using the Cluster

Once the CoresOnDemand team has completed the cluster setup and user creation (takes a couple of hours for most cases), customers can login and begin using the cluster. The CoresOnDemand clusters allow customers to use the connection method they are comfortable with. All connections to CoresOnDemand are encrypted and are protected by a firewall and an isolated network environment.

Step 1: Transfer files to the cluster:

Files can be transferred to the cluster using Secure Copy Protocol which creates an encrypted tunnel for copying files. A graphical tool is also available for Windows users (& it’s freeJ). Also, larger files can be loaded to the cluster manually by sending a DVD, Blu-ray disk or external storage device to PADT. The CoresOnDemand team will mount the volume and can assist in the copying of data.

Step 2: Connect to the cluster and start jobs

Customers can connect to the cluster through an SSH connection. This is the most basic interface where users can launch interactive or batch processing jobs on the cluster. SSH is secure, fast and very stable. The downside of SSH is that is has limited graphical capabilities.

Another option is to use the Nice Software Desktop Cloud Visualization (DCV) interface. DCV provides enhanced interactive 2D/3D access over a standard network. It enables users to access the cluster from anywhere on virtually any device with a screen and an internet connection. The main advantage of DCV is the ability to start interactive ANSYS jobs and monitor them without the need for a continuous connection. For example, a user can connect from his laptop to launch the job and later use his iPad to monitor the progress.

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Figure 1. 12 Million cell model simulated on CoresOnDemand

The CoresOnDemand environment also has the Torque resource manager implemented where customers can submit multiple jobs to a job queue and run them in sequence without any manual intervention.

Customers can use SCP or ship external storage to get data on the cluster. SSH or DCV can be used to access the cluster. Batch, interactive or Torque scheduler can be used to submit and monitor jobs.

All Done?

Once the simulation runs are completed customers usually choose one of two methods to transfer data back. First is to download the results over the internet using SCP (mentioned earlier) or have external media shipped back (External media can be encrypted if needed).

After the customer receives the data and confirms that all useful data was recovered from the cluster, CoresOnDemand engineers re-image the cluster to remove all user data, user accounts and logs. This marks the end of the lease engagement and customers can rest assured that CoresOnDemand is available to help…and it’s pretty fast too.

At the end of the lease customers can download their data or have it shipped on external media. The cluster is later re-imaged and all user data, accounts & logs are also deleted in preparation for the next customer.

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