Continue a Workbench Analysis in ANSYS MAPDL R15

stopsignThis article outlines the steps required to continue a partially solved Workbench based analysis using a Multi-Frame Restart and the MAPDL Batch mode.

In this article you will learn:

  • Some ways to interface between ANSYS Workbench and ANSYS MAPDL
  • How to re-launch a run using a Multi-Frame Restart in ANSYS Batch mode
  • The value of the jobname.abt functionality for Static Structural and Transient Structural analyses

Recently I was working in the ANSYS Workbench interface within the Mechanical application running a Transient Structural analysis. I began my run thinking that my workstation had the necessary resources to complete the analysis in a reasonable amount of time. As the analysis slowly progressed, I began to realize that I needed to make a change and switch to a computer that had more resources. But some of my analysis was already complete and I did not want to lose that progress. In addition, I wanted to be sure that I could monitor the analysis intermediately to ensure that it was advancing as I would like. This meant that however I decided to proceed I needed to make sure that I could still read my results back into Mechanical along with having the capability to restart again from a later point. Here were my options.

1: I could use the Remote Solve Manager (RSM) to continue running my analysis on a compute server machine. Check out this article for more on that.

I did use RSM in part but perhaps you do not have RSM configured or your computer resources are not connected through a network. Then I will show the other option you can use.

2: A Multi-Frame Restart using MADPL in ANSYS Batch mode

Here’s the process:

1. Make note of the current load step and last converged substep that your analysis completed when you hit the Interrupt Solution button
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2. Copy the *.rdb, *.ldhi, *.Rnnn files from the Solver Files Directory on the local machine to the Working Directory on the computing machine
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You can find your Solver Files Directory by right clicking on the Solution Branch in the Model Tree and selecting Open Solver Files Directory:
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3. Write an MAPDL input file with the commands to launch a restart and save it in the Working Directory on the computing machine (save with extension *.inp)

Below is an example of an input that will work well for restarting an analysis, but feel free to adjust it with the understanding that the ANSYS Programming Design Language (APDL) is a sophisticated language with a vast array of capability.
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4. Start the MADPL Product Launcher interface on the computing machine and:
    a: Set Simulation Environment to ANSYS Batch
    b. Navigate to your Working Directory
    c. Set the jobname to the same name as that of the *.rdb file
    d. Browse to the input file you generated in Step 3
    e. Give your output file a descriptive name
    f. Adjust parallel processing and memory settings as desired
    g. Run

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5. Look at the output file to see progress and monitor the run
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6. Write “nonlinear” in a text file and save it as jobname.abt inside the Working Directory to cleanly interrupt the run and generate restart files when desired
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The jobname.abt will appear briefly in the Working Directory

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The output file will read the following:
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Note that the jobname.abt interruption process is the exact process that ANSYS uses in the background when the Interrupt Solution button is pressed interactively in Mechanical
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Read more about the jobname.abt functionality in the Help Documentation links at the end of this article.

7. Copy all newly created files in Working Directory on the computing machine to the Solver Files Directory on the local machine
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8. Back in the Mechanical application, highlight the Solution branch of the model tree, select Tools menu>Read Results Files… and navigate to the Solver Files Directory and read the updated *.rst file
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After you have read in the results file, notice that the restart file generated from the interruption through the jobname.abt process appears as an option within the Mechanical interface under Analysis Settings
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9. Review intermediate results to determine if analysis should continue or if adjustments need to be made

10. Repeat entire process to continue analysis using the new current loadstep and substep

Happy solving!

Here are some useful Help Documentation sections in ANSYS 15 for your reference:

  • Understanding Solving:
    • help/wb_sim/ds_Solving.html
  • Mechanical APDL: Multiframe Restart:
    • help/ans_bas/Hlp_G_BAS3_12.html#BASmultrestmap52199

And, as always, please contact PADT with your questions!

Video Tips: Create and Display Custom Units in ANSYS CFD-Post

By: Susanna Young

ANSYS CFD-Post is a powerful tool capable of post-processing results from multiple ANSYS tools including FLUENT, CFX, and Icepak. There are almost endless customizable options in ANSYS CFD-Post. This is a short video demonstrating how to create and display a set of custom units within the tool. Stay tuned for additional videos on tips for more effective post-processing in ANSYS CFD-Post.

ANSYS Remote Solve Manager (RSM): Answers to Some Frequently Asked Questions

rsm-1For you readers out there that use the ANSYS Remote Solve Manager (RSM) and have had one or all of the below questions, this post might just be for you!

  1. What actually happens after I submit my job to RSM?
  2. Where are the files needed to run the solve go?
  3. How do the files get returned to the client machine, or do they?
  4. What if something goes wrong with my solve or in the RSM file downloading process, is there any hope of recovery?
  5. Are there any recommendations out there for how best to use RSM?

If your question is, how do I setup RSM as a user? You answers are here from a post by Ted Harris. The post today is a deeper dive into RSM.

The answers to questions 1 through 3 above are really only necessary if you would like to know the answer to question 4. My reason for giving you a greater understanding of the RSM process is so that you can do a better job of troubleshooting should your RSM job run into an issue.  Also, please note that this process is specifically for an RSM job submitted for ANSYS Mechanical. I have not tested this yet for a fluid flow run.

What happens when a job gets submitted to RSM?

The following will answer questions 1-3 above.

When a job is run locally (on your machine), ANSYS uses the Solver Files Directory to store and update data. That folder can be found by right clicking on the Solution branch in the Model tree and selecting Open Solver Files Directory.

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The project directory will be opened and you can see all of the existing files stored for your particular solution:
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When a job gets submitted to RSM, the files that are stored in the above folder will be transferred to a series of two temporary directories. One temporary directory on the client side (where you launched the job from) and one temporary directory on the compute server side (where the numbers get crunched).

After you hit solve for a remote solve, you will notice that your project solver directory gets emptied. Those files are transferred to a temporary directory under the _ProjectScratch directory:
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Next, these files get transferred to a temporary directory on the compute server. The files in the _ProjectScratch directory will remain there but the folder will not be updated again until the solve is interrupted or finished.

You can find the location of the compute server temporary directory by looking at the output log in the RSM queueing interface:
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If you navigate to that directory on your compute server, you will see all of the necessary files needed to run. Depending on your IT structure, you may or may not have access to this directory, but it is there.

Here is a graphical overview of the route that your files will experience during the RSM solve process.
 ss1ss2

Once your run is completed or you have interrupted it to review intermediate results and your results have been downloaded and transferred to the solver files folder, both of the temporary directories get cleaned up and removed. I have just outlined the basic process that goes on behind the scenes when you have submitted a job to RSM.

What if something goes wrong with my RSM job? Can I recover my data and re-read it into Workbench?

Recently, I ran into a problem with one of my RSM jobs that resulted in me losing all of the data that had been generated during a two day run. The exact cause of this problem I haven’t determined but it did force me to dive into the RSM process and discover what I am sharing with you today. By pin-pointing and understanding what goes on after the job is submitted to RSM, I did determine that it can be possible to recover data, but only under certain circumstances and setup.

First, if you have the “Delete Job Files in Working Directory” box checked in the compute server properties menu accessed from the RSM queue interface (see below) and RSM sees your job as being completed, the answer to the above question is no, you will not be able to recover your data. Essentially, because the compute server is cleaned up and the temporary directory gets deleted, the files are lost.
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To avoid lost data and prepare for such a catastrophe, my recommendation is that you or your IT department, uncheck the “Delete Job Files in Working Directory” box. That way, you have a backup copy of your files stored on the server that you can delete later when you are sure you have all of your files safely transferred to your solver files folder within your project directory structure.

The downside to having this box unchecked is that you have to manually cleanup your server. Your IT department might not like, or even allow you to do this because it could clutter your server if you do not stay on top of things. But, it could be worth the safety net.

As for getting your data back into Workbench, you will need to manually copy the files on the compute server to your solver files folder in your Workbench project directory structure. I explained how to access this folder at the beginning of this post. Once you have copied those files, back in the Mechanical application, with the Solution branch of your model tree highlighted, selects Tools>Read Results Files… (see below graphic), navigate to your solver files directory, select the *.rst file and read it in.

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Once the results file is read in, you should see whatever information is available.

Recommendations

  • Though it is possible to run concurrent RSM jobs from the same project, my recommendation is to only run one RSM job at a time from the same project in order to avoid communication or licensing holdups

  • Unless you are confident that you will not ever need to recover files, consider unchecking the “Delete Job Files in Working Directory” box in the compute server properties menu.

    • Note: if you are not allowed access to your compute server temporary directories, you should probably consult your IT department to get approval for this action.

    • Caution: if you uncheck this box, be sure that you stay on top cleaning up your compute server once you have your files successfully downloaded

  • Depending on your network speed, when your results files get large, >15GB, be prepared to wait for upload and download times. There is likely activity, but you might not be able to “see” it in the progress information on the RSM output feed. Be patient or work outside of RSM using a batch MAPDL process.

  • Avoid hitting the “Interrupt Solution” command more than once. I have not verified this, but I believe this can cause mis-communication between the compute server and local machine temporary directories which can cause RSM to think that there are no files associated with your run to be transferred.

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Default Contact Stiffness Behavior for Bonded Contact

p7It recently came to my attention that the default contact stiffness factor for bonded contact can change based on other contact regions in a model. This applies both to Mechanical as well as Mechanical APDL. If all contacts are bonded, the default contact stiffness factor is 10.0. This means that in our bonded region, the stiffness tending to hold the two sides of contact together is 10 times the underlying stiffness of the underlying solid or shell elements.

However, if there is at least one other contact region that has a type set to anything other than bonded, then the default contact stiffness for ALL contact pairs becomes 1.0. This is the default behavior as documented in the ANSYS Mechanical APDL Help, in section 3.9 of the Contact Technology Guide in the notes for Table 3.1:

“FKN = 10 for bonded. For all other, FKN = 1.0, but if bonded and other contact behavior exists, FKN = 1 for all.”

So, why should we care about this? It’s possible that if you are relying on bonded contact to simulate a connection between one part and another, the resulting stress in those parts could be different in a run with all bonded contact vs. a run with all bonded and one or more contact pairs set to a type other than bonded. The default contact stiffness is now less than it would be if all the contact regions were set to bonded.

This can occur even if the non-bonded contact is in a region of the model that is in no way connected to the bonded region of interest. Simply the presence of any non-bonded contact region results in the contact stiffness factor for all contact pairs to have a default value of 1.0 rather than the 10.0 value you might expect.

Here is an example, consisting of a simple static structural model. In this model, we have an inner column with a disk on top. There are also two blocks supporting a ring. The inner column and disk are completely separate from the blocks and ring, sharing no load path or other interaction. Initially all contact pairs are set to bonded for the contact type. All default settings are used for contact.
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Loading consists of a uniform temperature differential as well as a bearing load on the disk at the top. Both blocks as well as the column have their bases constrained in all degrees of freedom.
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After solving, this is the calculated maximum principal stress distribution in the ring. The max value is 41,382.
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Next, to demonstrate the behavior described above, we changed the contact type for the connection between the column and the disk from bonded to rough, all else remaining the same.
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After solving, we check the stresses in the ring again. The max stress in the ring has dropped from 41,283 to 15,277 as you can see in the figure below. Again, the only change that was made was in a part of the model that was in no way connected to the ring for which we are checking stresses. The change in stress is due solely to a change in contact type setting in a different part of the model. The reason the stress has decreased is that the stiffness of the bonded connection is less by a factor of 10, so the bonded region is a softer connection than it was in the original run.

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So, what do we as analysts need to do in light of this information? A good practice would be to manually specify the contact stiffness factor for all contact pairs. This behavior only crops up when the default values for contact stiffness factor are utilized. We can define these stiffness factors easily in ANSYS Mechanical in the details view for each contact region. Further, we need to always remember that ANSYS as well as other analytical tools are just that – tools. It’s up to us to ensure that the results of interest we are getting are not sensitive to factors we can adjust, such as mesh density, contact stiffness, weak spring stiffness, stabilization factors, etc.

Learn Linux on edX

edx_linuxThe balance of Linux vs. Windows for simulation users is always in flux. For some time it was predicted that Windows would win the battle but in recent years Linux has made a resurgence, especially on clusters and in the cloud.  We strongly recommend that ANSYS users who want to be power users gain a good understanding of Linux from a user and sysadmin perspective. Especially CFD users since they are most likely to be solving on a Linux devices.  Too many of the people we interface with are left at the mercy of an IT support team that doesn’t know, or even fears Linux.

The best way to solve this problem is to learn Linux yourself. To help people get there, recommended a few books and “learn by doing.” Now we have a better option.

edX offers an Introduction to Linux class that looks outstanding, and you can audit it for free or take the course for real for a $250 minimum contribution.  The quality of these courses is fantastic. The material is thorough and practical.

If you do take the class, give us some feedback when you finish in the comments below.

Here is the video describing the course.  

Using Probes to Obtain Contact Forces in ANSYS Mechanical

Recently we have had a few questions on obtaining contact results in ANSYS Mechanical. A lot of contact results can be accessed using the Contact Tool, but to obtain contact forces we use Probes. Since not everyone is familiar with how it’s done, we’ll explain the basics here.

Below is a screen shot of a Mechanical model involving two parts. One part has a load that causes it to be deflected into the other part.

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We are interested in obtaining the total force that is being transmitted across the contact elements as the analysis progresses. Fortunately this is easy to do using Probes in Mechanical.

The first thing we do is click on the Solution branch in the tree so we can see the Probes button in the context toolbar. We then click on the Probe drop down button and select Force Reaction, as shown here:

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Next, we click on the resulting Force Reaction result item under the Solution branch to continue with the configuration. We first change the Location Method from Boundary Condition to Contact Region:

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We then specify the desired contact region for the force calculation from the Contact Region dropdown:

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Note that the coordinate system for force calculation can either be Cartesian or Cylindrical. You can setup a coordinate system wherever you need it, selectable via the Orientation dropdown.

There is also an Extraction dropdown with various options for using the contact elements themselves, the elements underlying the contact elements, or the elements underlying the target elements (target elements themselves have no reaction forces or other results calculated). Care must be taken when using underlying elements to make sure we’re not also calculating forces from other contact regions that are part of the same elements, or from applied loads or constraints. In most cases you will want to use either Contact (Underlying Element) or Target (Underlying Element). If contact is non-symmetric, only one of these will have non zero values.

In this case, the setting Contact (Contact Element) was a choice that gave us appropriate results, based on our contact behavior method of Asymmetric:

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Here are the details including the contact force results:

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This is a close up of the force vs. ‘time’ graphs and table (this was a static structural analysis with a varying pressure load):

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***** SUMMATION OF TOTAL FORCES AND MOMENTS IN THE GLOBAL COORDINATE SYSTEM *****

FX = -0.4640219E-04
FY = -251.1265
FZ = -0.1995618E-06
MX = 62.78195
MY = -0.1096794E-04
MZ = -688.9742
SUMMATION POINT= 0.0000 0.0000 0.0000

We hope this information is useful to you in being able to quickly and easily obtain your contact forces.

Video Tips: Using ACT to change Default Settings in ANSYS Mechanical

A short video showing how ACT (ANSYS Customization Toolkit) can be used to change Default Settings for analyses done in ANSYS Mechanical.  This is a very small subset of the capabilities that ACT can provide.  Stay tuned for other videos showing further customization examples.

The example .xml and python file is located below.  Please bear in mind that to use these “scripted” ACT extension files you will need to have an ACT license.  Compiled versions of extensions don’t require any licenses to use.  Please send me an email (manoj@padtinc.com) if you are wondering how to translate this example into your own needs.

NLdefaults

Flownex and PADT Sponsor University of Houston’s Rankin Rollers Team

rankin-rollers-logoA group of enthusiastic students at the University of Houston are doing their part at solving that age old academia problem: not enough hand’s on experience.  They are designing and building a working steam turbine for the schools Thermodynamics lab so students can experiment with a Rankin cycle, learn how to take meaningful measurements, and study how to control a real thermodynamic system.

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Look! Flownex and PADT on Social Media! Thanks for the plug guys.
After meeting a team member at the 2014 Houston ANSYS User conference, PADT saw a great opportunity to help the team by providing them with access to a full seat of Flownex SE so that they can create a virtual prototype of their steam turbine and the control system they are developing. 

The four team members have the following goals for their project:

    1. Create a fully automated system control
    2. Create system with rolling frame for ease of transport
    3. Create system with dimensions of 4x2x3.5 ft
    4. Deliver pre-made lab experiments
    5.  Produce an aesthetically pleasing product

    Flownex should be a great tool for them, allowing the team to simulate the thermodynamics and flow in the system as well as the system controls before committing to hardware. 

    You can learn more about the team on their Facebook page here, or on their website here

    We hope to share their models and what they have learned when their project is complete. If you are interested in using Flownex for your work or school project, contact PADT.

    steam-turbine-table-setup
    This is the Team’s proposed configuration for the final test bench.
    flow-schematic
    We can’t wait to see this flow diagram translated into Flownex.

    A 3D Mouse Testimonial

    The following is from an email that I received from Johnathon Wright.  I think he likes his brand new 3DConnexion Space Pilot Pro.
    -David Mastel
      IT Manager
      PADT, Inc.

    ——————-

    top-panel-deviceRecently PADT became a certified reseller for 3Dconnexion. Shortly following the agreement a sleek and elegant SpacePilot PRO landed on my desk. Immediately the ergonomic design, LCD display, and blue LED under the space ball appealed to the techie inside of me. As a new 3D mouse user I was a little skeptical about the effectiveness of this little machine, yet it quickly has gained my trust as an invaluable tool to any Designer or Engineer. On a daily basis it allows me to seamlessly transition from CAD to 3D printing software and then to Geomagic Scanning software, allowing dynamic control of my models, screen views, hotkeys and shortcuts.

    Outside of its consistency as an exceptional 3D modeling aid, the SpacePilot PRO also has a configurable home screen that allows quick navigation of email, calendar or tasks. This ensures that I can keep in touch with my team without having to ever leave my engineering programs, which is invaluable to my production on a daily basis. Whether you are a first time user who is looking to tryout a 3D Mouse for the first time or an experienced 3D mouse user who is looking to upgrade, you need to check out the SpacePilot Pro. I can’t imagine returning to producing CAD models or manipulating scan data without one. Combine the SpacePilot PRO cross-compatibility with its programmability and ease of use and you have a quality computer tool that applies to a wide range of users who are looking at new ways to increase productivity.

    Link to You Tube video – watch it do its thing along with a look at my 3D scanning workstation, the GEOCUBE: http://youtu.be/fsfkLPaZJe4

    Johnathon Wright
    Applications Engineer,
    Hardware Solutions
    PADT, Inc.

    ———————————————————————————————-
    Editors Note:

    Not familiar with what a 3D Mouse is?  It is a device that lets a use control 3D objects on their computer in an intuitive manner. Just as you move a 2D mouse on the plane of your desk, you spin a 3D Mouse in all three dimensions.  Learn more here

    spacepilot-pro-cad-professional-2-209-p

    Integrating ANSYS Fluent and Mechanical with Flownex

    Component boundaries generated in Flownex are useful in CFD simulation (inlet velocities, pressures, temperatures, mass flow). Generation of fluid and surface temperature distribution results from Flownex can also be useful in many FEA simulations. For this reason the latest release of Flownex SE was enhance to include several levels of integration with ANSYS.  

    ANF Import

    By simply clicking on an Import ANF icon on the Flownex Ribbon bar users can select the file that they want to import. The user will be requested to select whether the file must be imported as 3D Geometry which conserves the coordinates system or as an isometric drawing.

    The user can also select the type of component which should be imported in the Flownex library. Since the import only supports lines and line related items this will typically be a pipe component.

    Following a similar procedure, a DXF importer allows users to import files from AutoCAD.

    This rapid model construction gives Flownex users the ability to create and simulate networks quicker. With faster model construction, users can easily get to results and spend less time constructing models.

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    ANSYS Flow Solver Coupling and Generic Interface

    The Flownex library was extended to include components for co-simulation with ANSYS Fluent and ANSYS Mechanical.
    p2

    These include a flow solver coupling checks, combined convergence and exchanges data on each iteration, and a generic coupling that can be used for cases when convergence between the two software programs is not necessary.

    The general procedure for both the Fluent and Mechanical co-simulation is the same:

    1. By identifying specified named selections, Flownex will replace values in a Fluent journal file or ds.dat file in the case of Mechanical.
    2. From Flownex, Fluent/Mechanical will then be run in batch mode
    3. The ANSYS results are then written into text files that are used inputs into Flownex.
    4. When applicable, specified convergence criteria will be checked and the procedure repeated if necessary.

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    Learn More

    To learn more about Flownex or how Flownex and ANSYS Mechanical contact PADT at 480.813.4884 or roy.haynie@padtinc.com.  You can also learn more about Flownex at www.flownex.com.

    FDA Opening to Simulation Supported Verification and Validation for Medical Devices

    FDA-CDRH-Medical-Devices-SimulationBringing new medical device products to market requires verification and validation (V&V) of the product’s safety and efficacy. V&V is required by the FDA as part of their submission/approval process. The overall product development process is illustrated in the chart below and phases 4 and 5 show where verification is used to prove the device meets the design inputs (requirements) and where validation is used to prove the device’s efficacy. Historically, the V&V processes have required extensive and expensive testing. However, recently, the FDA’s Center for Devices and Radiological Health (CDRH) has issued a guidance document that helps companies uses computational modeling (e.g FEA and CFD) to support the medical device submission/approval process.

    FDA-Medical-Device-Design-Process-Verification-Validation
    Phases and Controls of Medical Device Development Process, Including Verification and Validation
     The document called, “Reporting of Computational Modeling Studies in Medical Device Submissions”, is a draft guidance document that was issued on January 17th, 2014. The guidance document specifically addresses the use of computation in the following areas for verification and/or validation:

    1. Computational Fluid Dynamics and Mass Transport
    2. Computation Solid Mechanics
    3. Computational Electromagnetics and Optics
    4. Computational Ultrasound
    5. Computational Heat Transfer

    The guidance specifically outlines what form reports need to take if a device developer is going to use simulation for V&V.  By following the guidance, a device sponsor can be assured that all the information required by the FDA is included. The FDA can also work with a consistent set of input from various applicants. 

    drug-delivery-1-large
    CFD Simulation of a Drug Delivery System. Used to Verify Uniform Distribution of Drug

    Computational Modeling & Simulation, or what we usually call simulation, has always been an ideal tool for reducing the cost of V&V by allowing virtual testing on the computer before physical testing. This reduces the number of iterations on physical testing and avoids the discovery of design problems during testing, which is usually late in the development process and when making changes is the most expensive. But in the past, you had to still conduct the physical testing. With these new guidelines, you may now be able to submit simulation results to reduce the amount of required testing.
    mm_model_stresses
    Simulation to Identify Stresses and Loads on Critical Components While Manipulating a Surgical Device

    Validation and verification using simulation has been part of the product development process in the aerospace industry for decades and has been very successful in increasing product performance and safety while reducing development costs.  It has proven to be a very effective tool, when applied properly.  Just as with physical testing, it is important that the virtual test be designed to verify and validate specific items in the design, and that the simulation makes the right assumptions and that the results are meaningful and accurate.

    PADT is somewhat unique because we have broad experience with product development, various types of computational modeling and simulation, and the process of submission/approval with the FDA. In addition, we are ISO 13485 certified. We can provide the testing that is needed for the V&V process and employ simulation to accelerate and support that testing to help our medical device customers get their products to market faster and with less testing cost.  We can also work with customers to help them understand the proper application of simulation in their product development process while operating within their quality system.

    Flownex 2014 Released and Webinars Announced

    987786-flownex_simulation_environment-11_12_13The June release of Flownex SE software includes numerous updates for companies that model thermal fluid systems; videos and webinars are available to showcase the impact of these enhancements.

    Flownex SE has increased the ability of engineers to accurately model their fluid-thermal with the release of version of Flownex 2014 on June 19th, 2014. The program is known for its in ease of use, breadth of capability, and depth of functionality.  With enhancements in turbomachinery modeling, support for 3D networks, GIS data import, heat transfer and a myriad of additional new features impacting efficiency, integration, and automation, this release expands the industries that can take advantage of it, and will help current users model their systems more accurately with greater ease.

    7271351-Flownex2014-GIS

    To help the user community understand the impact of these significant enhancements, PADT is offering two webinars. Both webinars will include a brief introduction to the tool, so if you are new to Flownex SE you will have a good foundation to get started.

    Webinar Sign-Up:

    Overview webinar: July 24, 2014, 1:00-2:00 PM MST

    This webinar will focus all of the new features in Flownex SE 8.3.6.  
    Register here

    7271351-Flownex2014-Rotating_ComponentsTurbomachinery webinar: August 7, 2014, 1:00-2:00 PM MST

    This webinar will be a deep dive into the extensive turbomachinery capabilities added in this release, and will be of interest to anyone simulating turbine engines, pumps, blowers, or other rotating machinery that involves fluids.
    Register here

    All registrants will be sent links to recordings so they can view the presentation even if they cannot attend them live.

    Video Resources:

    A video is also available that hits the important new capabilities: 

    If you are new to Flownex SE, visit PADT’s Flownex page to learn more:  

    Key Features:

    The key features introduced in Flownex 2014 (Flownex SE 8.3.6) are:  

    1. Rotating components, Swirl Boundary, and General Turbine and Compressor Models
    2. Importing and Geometries
    3. GIS File Support
    4. Connections to ANSYS Products
    5. Link to Mathcad
    6. Graphical Script Generation Tool
    7. New Designer Tools to Quickly Model Common Systems.
    8. Five Additional Convection Models
    9. Exit Thrust Nozzle Added
    10. Additional Enhancements ranging from 3D Graphs to Support for Miter Bends in Piping

    7271351-Flownex2014-Pipe-Results

    Visit here to see a detailed list of these key features, or download the complete release notes here.

    These additional features reflect the growing diversity of industries that are using Flownex SE to model their systems.  Users in oil and gas, mining, chemical processing, and turbomachinery will all see additional accuracy, functionality, and efficiency from this release. Built on an existing strong foundation that offers un-paralleled capability with  intuitive ease of use, a short look at Flownex SE will show you why so many users around the world are choosing it as their thermo-fluid modeling tool.

    PADT is the distributor of Flownex SE in the United States.  Our experienced staff is eager to discuss your system modeling needs and is ready to show you how Flownex SE can start delivering value almost immediately. Contact us today to meet with our experts.

    Video Tips: Workflow for Designing Electric Motors in ANSYS

    A quick video showing you a great workflow for designing electric motors. It shows going from a quick template based design tool to a full 3D analysis tool.

    Electric motor have contributed a lot to the development of the industrial technologies present in the today’s modern world. There have been many types of it for specific and different applications. From industrial to home appliances, electric motors are an important part of our daily lives. Even commuting scooters have little electric motors in them that propel the boards.

    Top 10 New Thermal Fluid Modeling Capabilities in Flownex 2014

    3D graphWe are pleased to announce the release of Flownex SE 2014.  This is a very exciting release for all of us involved in Flownex because it introduces a mix of advanced features and usability enhancements – we love better and easier.  We will be publishing more information about this release, as well as videos and webinars. While we set all of that up, we wanted to whet everyone’s appetite and give you a list of what we feel are the 10 most important enhancements.

    1. Rotating components, Swirl Boundary, and General Turbine and Compressor Models 
      A new library has been added which models rotating flow on a system level. Focusing on secondary flow and heat transfer in turbine engines, it includes all the components needed including compressors, turbines, seals, gaps, nozzles, and cavities. A complete library for Steam Turbine modeling was also added. 
    2. Importing and Geometries
      Users can read in 2D and 3D layout files in common formats and directly create Flownex models from the geometry. The model and results can then be visualized with the 3D geometry.
    3. GIS File Support
      When modeling systems that cover a large area, such as water or gas pipelines, the geographical data can be imported for display and to automatically include altitude into the model. 
    4. Connections to ANSYS Products
      Users can import 3D Pipe geometry as an ANF file, and connect to ANSYS Mechanical and ANSYS Fluent for co-simulation.
    5. Link to Mathcad
      Users can transfer parametric data to and from Mathcad worksheets
    6. Graphical Script Generation Tool
      Users can use Quick Script to create complex scripts to customize their processes or models without having to learn the full scripting language
    7. New Designer Tools to Quickly Model Common Systems.
      Designer tools atomically iterate on a user’s model to calculate unknown values for them. This release includes tools for calculating mass flow when only pressure is known at a boundary, automatically calculating steady state conditions in a two-phase tank, and a component designer that calculates input parameters for common components so that those components deliver the users requested mass flow.
    8. Five Additional Convection Models 
      Based on user input, five new models were added to the Dittus-Boelter correlation for calculating heat transfer coefficients: tube, shell-side single phase, shell-side horizontal tube condensation, ribbed wall channel, and channel with pedestals. 
    9. Exit Thrust Nozzle Added
      New model in subsonic and supersonic flow at the outlet of a flow network with gasses and superheated fluids
    10. Additional Enhancements:
      Support for miter bends in piping
      3D graphs
      Radiation supports multiple surface enclosures
      The range of methane two phase fluid was increased
      Support for 64 bit 
      Several more values can be changed during a transient solution

    The best way to learn more about these additions, or anything about Flownex, is to contact Roy Haynie at roy.haynie@padtinc.com or 480-813-4884.  
    There is also some more detailed material here:

     

    Recommended Free Utilities for the ANSYS User’s Toolbox

    free-stuffWhat do you have in your toolbox? The ANSYS suite of tools is pretty comprehensive.  But an efficient user always has a collection of utilities that they use with ANSYS products to automate processes, convert data, and scrub results.  In 2008 we published a list of free and commercial tools that we were using at PADT, and web results show that it is one of our more popular posts. So we thought it was a good time to revisit and update those lists.

    We will start with the free tools, well because everyone loves something for free. This is by no means a comprehensive list, these are simply the tools we currently use here at PADT. If you have alternative suggestions, please leave them in a comment.  I tried to put them in some logical grouping, but failed.  So here they are, in no particular order:

    untitled python
    Scripting Language
    www.python.org

    Every good simulation user needs scripting.  We spend a lot of time dealing with large amounts of data and setting up all sorts of complicated processes.  Scripting can be used to create, modify, sift through, or translate text versions of our models, loads, and results.  Some users like to stick with APDL and never leave ANSYS, some know Matlab very well.  Others may use newer languages like Lua or older ones like perl.
    Here at PADT we have found that python is the best tool for scripting outside of ANSYS MAPDL (we use APDL if we are in the program).  Not only is it easy to learn and use, it has hundreds of free libraries that do almost anything you want. Lots of people know it, and you are not dependent on some other piece of software. Python also works on Linux and Windows. In addition, most CAE tools these days support python scripting.  This is certainly true of the Workbench project page and ANSYS ACT for ANSYS Mechanical. 

    Alternatives: perl, Lua, linux shell scripts.

    vtk VTK
    Visualization Library
    www.vtk.org

    Did you ever wish there was a toolkit out there that you could use to quickly build a visualization tool?  I know I spent days of my early career writing simple tools from scratch, and spending most of my time on graphics stuff.  Well, VTK is that toolkit.  It consists of C++ class libraries, and includes interpreters for Tcl/Tk, Java, and python.  With python, you can create little applications very quickly without having to know a full object oriented programming language.  The resulting graphics are fast and attractive. If you are going to be writting your own vertical application that works with your FEA or CFD tool, use VTK for the graphics.

    paraview ParaView
    Visualization Tool
    www.paraview.org 

    The first time you use ParaView, your response will most likely be OMG. It is a visualization tool written in VTK.  It reads most FEA and CFD formats, along with pretty much any faceted geometry data format.  [Unfortunately it is not reading the current ANSYS ds.dat file that ANSYS mechanical writes (or a cdb file)  I’ll try and submit a bug report. ]  But it does read a CGNS file, which you can export to from Workbench. 

    But we don’t use it for working with ANSYS files so much, we have tools for that. We use it to deal with other file formats like STL, NASTRAN, CGNS, ExodusII, etc…  Very handy and intuitive to use. It is also an example of how powerful VTK is.

    Alternatives: OpenCascade

    notepad  Notepad++
    Source Code Editor
    notepad-plus-plus.org 

    This is a great text editor.  Newer than most, it builds on the dozens of previous text editors out there.  It does syntax highlighting and auto completion for many languages. For ANSYS users, it has a powerful column editing mode, very sophisticated search and replace, and macro recording and playback.  I’m not aware of an APDL syntax highlighter, but you have PeDAL for that. There are a lot of text editors out there, and this one has bubbled to the top as the most popular at PADT.

    Alternatives: Notepad, PSPad, TextPad, UltraEdit, and dozens more

    vim Vim/GVim
    VI Text Editor
    www.vim.org 

    Some people love VI, the old Unix text editor.  I’m one of those people. I’ve been using VI for over 30 years.  So I have to have a VI editor on my machine and I use it instead of Notepad++ or other text editors. Because I don’t want to touch a mouse, I want to [Esc] jjjj llll .  instead.  Vim is really the only good VI tool out there anymore, and it comes standard on most Linux installs instead of the old Vi.  The windows version works great.

    Alternatives: Elvis, Vile, Lemmy

    openoffice OpenOffice
    Word Processor, Spreadsheet, Slide Shows, Database
    www.openoffice.org 

    Let’s be honest, MS Office dominates this type of tool. It works, everyone has it, and everyone knows it.  But sometime you don’t want to fork over cash to those guys in Seattle. Or maybe you spend your day on Linux.  OpenOffice is about 90% of what MS Office does, and it is free. It kind of died at Sun when they got bought by Oracle.. Since Apache has taken up the market, it has seen a lot of enhancements.

    Many people just think about the word processor, but remember it has a simple drawing tool, an equation editor, a a very good database program.

    Alternatives: GoogleDocs, LibreOffice

    latex LaTeX
    Document Perpetration System
    www.latex-project.org 

    How do you tell an engineer with an advanced degree from one who just has a BS?  The one with the MS or PhD like LaTeX.

    Traditionally the tool of thesis writers, LaTeX has significant utility for the ANSYS user.  It allows you to create nice looking documents by imbedding tags in the document.  A pain when we have WYSIWYG editors, but very useful if you want to use scripting to create a document.  It is also a great way to create very good looking equations and tables.  Think of it as HTML for nice looking documents.

    Alternatives: Word Processors

    cutepdf CutePDF
    PDF Creator/Writer
    www.cutepdf.com 

    This tool is not as important as it once was, since many programs write to PDF for you. But every once in a while you run across one that does not.  It installs like a printer, so anything program with a print command allows you to save as PDF. 

    Alternatives: Adobe Online PDF Creator, PDF reDirect, PDFCreator, and a ton more.

    adobe-reader-logo Adobe Reader
    PDF Viewer
    get.adobe.com/reader 

    I almost left this off the list, but to be fair I included this. If you don’t have Acrobat Reader, you must live in a cave.  It is pretty much required to do business in this day and age.

    ghostscript

    Ghostscript
    Ghostview
    GSView

    PostScript Tools
    pages.cs.wissc.edu/~ghost 

    Ghostscript is an old Gnu project that contains tools for working with PostScript.  Ghostview is the viewing tool on Linux, although it has been replaced by GV.  GSView is a viewer for Windows.  Look at the website to learn about which tool you should be using.

    If you just look at PDF’s, then Adobe Reader is all you need. But if you have an older program that output PostScript directly, or you want to write a tool that create PostScript, then this toolset is for you.

    windows-snipping 

    Windows Snipping Tool
    Screen Capture Tool
    en.wikipedia.org/wiki/Snipping_Tool 

    This comes with all modern Window’s operating systems.  And, to be honest, this is the one free utility most of us use more than any other.  Who saves images to files any more, we just snip them!  If you don’t have it in your task bar, put it there and get used to using it. 

    Your Linux Desktop Environment will have a similar tool: KSnapshot or GNOME Screenshot

    camstudio

    CamStudio
    Screen Capture Tool
    camstudio.org 

    CamStudio is an open source tool for capturing video and audio off your screen.  Now one may want this to create screen grabs of “Lost in Space” reruns… but what does an ANSYS user need this for.  We use it to make tutorials for other users.  It is a great way to capture what you are doing on your screen for training or to share with co-workers.

    Alternatives:  We mostly use commercial tools for this… see the next article.

    gimp-logo

    GIMP
    Image Editing Tools
    www.gimp.org 

    I hate the name of this product. The politically-correct-Berkley-grad in me finds it very distasteful. But it stands for Gnu Image Manipulation Program.  It is not Adobe PhotoShop, but every release it gets closer. And in some areas it is better. It runs on Linux and Windows, always a plus.  We use it on our Unix machines to crop and clean up images. It can also be used to combine a series of images into an Animated GIF.  It is not bad at deleting backgrounds to make images with transparency for presentations as well.  It also has a fairly good vector creation layer.

    We used to recommend a mixture of free tools to deal with image manipulation and editing, but now we feel that GIMP does it all.

    Alternatives; ImageMagick, MS Paint

    Movie to GIF MovieToAniGif
    Make Animated GIF’s from AVI’s
    www.evanolds.com/movtogifsimple.html

    Everyone uses Microsoft PowerPoint to do presentations, and for most things it works great. But one thing is really sucks at is animations: you have to keep the movie files you are showing in the same directory because you can not embed them.  The simplest solution to this problem is to convert your animations into animated GIF files. Then insert those in your presentation. It also solves the problem of putting animations on your website without using YouTube or Flash.

    The tool we use mostly is Move to Animated GIF Converter.  It is old, the last version came out in 2010, but it still works just fine.  Not much to it, point it at an AVI file and then save it as an animated GIF.

    Alternatives: There are a bunch of tools out there, we have not used any so can’t really recommend an alternative.

    engauge-digitizer Engauge
    Converts Images of Graphs into Data
    digitizer.sourceforge.net

    Have you ever asked someone for material properties and you get a scan of a phototcopy of a book page back?  It happens less these days than it used to but you still sometimes get an image of a graph rather than a spreadsheet file.  Have no fear, Engauge is here!  It takes your image and allows you to identify the axis and the scale, then the data.  With a few clicks you have a table of useful data. 

    Alternatives: A ruler.

    Gnuplot Gnuplot
    Plotting Tool
    www.gnuplot.info

    Most FEA tools have their own 2D and 3D Graphing options, and of course Excel does a pretty good job. But sometimes you need more, or you want a plotting tool you can script. Gnuplot is that tool. It has been around forever and has about every type of graph imaginable. As a command line based program with its own scripting language, it can be generated by your programs to get the exact plot that you want.

    Alternatives: Python’s matplotlib or PyQtGraph, Scilab

    scilab Scilab
    Numerical Computation Tool
    www.scilab.org

    We don’t us a lot of Matlab here at PADT, we try and beat it out of new grads when we hire them… no not really.  It is a tool that our younger engineers are used to using.  The problem is it is kind of expensive when you use it every once in a while. Scilab is a nice open source alternative.  It works well and runs on Linux and Windows. 

    Alternatives: Julia, Sage.

    Remote_desktop_connection_icon

    Windows Remote Desktop
    Remote Desktop Tool
    Built in to Windows Operating Systems

    This is another “free” utility that comes with the windows operating system. Strictly speaking, it is not free because you paid for Windows, but it is so important, I thought it it was worth mentioning. 

    Accessing your a windows computer remotely was something we can now do all the time, even from a mobile device. And internet connections are fast enough to where you can do real work from a coffee shop, home, or even from an airplane with WiFi. 

    More importantly, in March of 2014, Microsoft released apps for iOS, Android, and Mac that work really, really well. We had been using 3rd party apps that were OK, but the new MS apps are great and I log on to my desktop all the time from my iPad and work fairly productively.

    vnc

    VNC
    Remote Desktop Tool
    www.tightvnc.com
    www.realvnc.com

    Remote Desktop works great for Windows boxes.  But if you want to do a remote desktop thing with Linux, or cross platform, we recommend VNC.  There are a ton of VNC tools out there, we seem to use tightVNC, and realVNC.  You need a server on the remote machine, and a viewer on the machine you are using. The viewers are free, not all servers are free.  There are also apps for iOS and Android for VNC viewers.

    We recommend using VNC only if you are connecting to a Linux machine from a Windows machine and you don’t want to mess with an X11 server on your Windows Machine (See below for X11 servers for Windows).  VNC does a pixel copy across the network, which is not as fast as X11 or Remote Desktop that send primitives back and forth.

    We have not had time to investigate VNC tools like TurboVNC that use VirtualGL and other tools to speed up the sending of the graphics window back and forth. NX (see below) uses VirtualGL

    Alternatives: Tons, just google.

    NX

    NX
    Remote X11 Desktop Client and Server
    www.nomachine.com

    Above we talk about Remote Desktop and VNC as ways to see remote machines.  If you want to see a Linux machine the best free way we have found is to use NX. This is one of those open source tools that is free and not free, and can get confusing.  It works like VNC in that you need a server on your remote machine, and a client on your machine. The client from www.nomachine.com is free.  The server is something you need to load on the remote machine, and probably comes in your Linux distribution. FreeNX seems to be the most popular.

    You should get very nice performance for 3D graphics on your internal internet, and not bad over the internet either.  We recomend NX over Cygwin if you don’t need a full unix clone on your windows machine, if you are just logging in to a LInux box, use NX.

    (and yes, we hate that the name is the same as the CAD/PLM tool… causes great confusion)

    Alternatives: Cygwin, VNC

    cygwin cygwin
    Linux on Windows
    www.cygwin.com

    If you need more than visualization on a remote Linux machine from your Windows box, you actually want to run Linux on top of Windows without rebooting or using a virtual machine, then you need cygwin.  It is a fairly full linux distribution that runs on Windows, including full X11 capability.  We don’t recommend it for people who are not Linux savvy, but if you are and you want to work in that environment, then it works very well.

    putty putty
    ssh Tool
    www.putty.org

    The best, and most secure, way to connect to a Linux machine is through SSH. If you have NX or cygwin you just open up a terminal and connect. But what if you just want a text connection. Putty is a simple tool that will store your connections and let you log right in and provide you with that terminal.  Better yet, it has an SCP tool (ssh copy) that is very handy for transferring files between machines.

    dropbox dropbox
    File sharing Tool
    www.dropbox.com

    There are a ton of “cloud” tools out there that let you load a file up on a server in the sky, backing it up or sharing it with others.  We use Dropbox at PADT for a couple of reasons.  The first is that it is more than a cloud solution, the files you put on Dropbox get copied to all of the computers you have that are connected to your Dropbox.  I keep all the essential files I need every day, and for whatever project I’m working on in a Dropbox folder and I have access to it at home, on my laptop, even on my iPad. 

    I also use it to transfer files to other people who don’t know what FTP is.

    Alternatives: Box, Copy, GoogleDrive (with Sync)

    filezilla filezilla
    FTP Tool
    www.filezilla-project.org

    Real simulation users FTP from the command line… and waste time doing so.  FileZilla is a great tool that uses a GUI to connect to FTP servers and transfer files by dragging and dropping.  It makes finding files, transferring multiple files, and monitoring those big transfers a breeze.

    Alternatives: ftp command line, cURL,lftp

    7zip 7-Zip
    File Compression Tool
    www.7-zip.org

    This is the most capable windows based compression tool we have found.  For many people the built in compression in Windows is fine, but if you want other options, and the ability to work with formats besides .ZIP ( including TAR, GZIP, RAR, LZH) this is the preferred tool.

    Alternatives: windows compression, we have not used any other free tools for this

    Encryption

    I was going to recommend two tools for encryption: TrueCrypt and PGP.  But it looks like both tools are in flux right now. 

    TrueCrypt makes virtual drives as files. When you decrypt them they show up as a drive on your machine. Very handy for achieving any special security concerns you may have.  But in march it was mysteriously shut down. They recommend that you use BitLocker which comes free with Windows.  We have not tried it so we can’t recommend it. Too bad, it was a great tool.  An alternative is PGPDisk, but that costs money or you have to compile it yourself.

    PGP encrypts files and had great email plug-ins. It was a nice tools for sending customer data back and forth in a secure way.  It was purchased by a series of companies and ended up sort of becoming static. You can read about it on Wikipedia. The good news is that there is an open source version called PGP, available on www.pgpi.org.  You want the GnuPG version which is free.  There are links here to PGPDisk source code as well.

    Bottom line, if you need to encrypt, you might as well pay for a commercial version that is supported.

    So, that is all of the tools we could think of, a very diverse list.  Remember, put any other suggestions you have in the comments below.