PADT is hosting a series of free training classes to introduce users to ANSYS AIM. We have pasted the invitation below. You can register here. We are very excited about this new tool from ANSYS, Inc. and are eager to share it with everyone. Look for more AIM information on this blog in the near future.
Among the magical skills engineers use in their daily awesomeness is their ability to bend the time fabric of the universe and perform tasks in almost impossible deadlines. It’s as if engineers work long hours and even work from home, while commuting and even at the coffee shop. Wait, is that what they actually do?
Among a myriad of tools that facilitate remote access and desktop redirection available, one stands out with distinction. NICE-Software developed a tool called Desktop Cloud Visualization (DCV for short). DCV has numerous advantages that we will get into shortly. The videos below give a general idea of what can be achieved with NICE-DCV.
Here is a video from the people at NICE:
And here is one of two PADT Employees using an iPhone to check their CFD results:
Advantages of Nice-DCV
Physical location of cluster/workstation or the engineers becomes irrelevant
Because engineers have fast, efficient and secure access to their workstations and clusters, they no longer need to be in the same office or on the same network segment to utilize the available compute resources. They can utilize NICE-DCV to create a fast, efficient and encrypted connection to their resources to submit, monitor and process results. The DCV clients are supported on Windows, Linux & IOS and even have a stand-alone Windows client that can be run on shared or public computers. In a recent live test, one of our engineers was travelling on a shuttle bus to a tiny ski town in Colorado, he was able to connect over the courtesy Wifi, check the status of his jobs and visualize some of the results.
The need for a powerful laptop or remote workstation to enable offsite work is no longer the only solution
There is no need for offsite engineers lug around a giant laptop in order to efficiently launch and modify their designs or perform simulation runs. Users launch the DCV client, connect to their workstation or cluster and are immediately given access to their desktop. No need to copy files, borrow licenses or transfer data. Engineers don’t need to create copies of files and carry them around on the laptops or on external storage which is an unnecessary security risk.
“If it ain’t broken don’t fix it!”
Every engineer uses ANSYS in his own special way. Some prefer the good old command line for everything even when a flashy GUI option is available. Others are comfortable using the Windows like GUI interface and would
Opens the door for GUI-only users to utilize large cluster resources without a steep learning curve or specialized tools.
Nice-DCV makes the use of ANSYS on large HPC clusters within reach for everyone. Engineers can log into pre-configured environments with all of the variables needed for parallel ANSYS runs already defined. Users can use can have their favorite ANSYS software added to the desktop as shortcuts or system admins can write small scripts or programs that serve as an answer file for custom job scripts.
From 0-60 in about…10 Minutes
For an engineer with the smallest amount of system administration skills it takes about 10 minutes to install the Nice-DCV server and launch the first connection. It’s surprisingly simple and straightforward on both the server and the client side. The benefits of Nice-DCV can be immediately realized in both simplified cluster administration and peace of mind for both the engineers and the system admins.
PADT’s CoresOnDemand and Nice-DCV
The CoresOnDemand service that PADT introduced last year utilizes the Nice-DCV tool to simplify and enhance the user experience. If you are interested in a live demo on Nice-DCV or the CoresOnDemand environment contact us either by phone: 480-813-4884 or by email firstname.lastname@example.org. For more information please visit: CoresOnCemand.com
(Note: some of the social media posts had a typo in the title, that was my fault (Eric) not Ahmed’s…)
Palm trees and movie stars. Endless beaches and deserts that fade to the horizon. Aerospace companies, world class universities, med device developers, and toy manufacturers. Oil, freeways, and big construction. Southern California. A place larger and more diverse than most countries in the world. PADT has done work in the area since our first weeks in business. As our business continued to grow, our customers started asking when we were opening up a local office, but the time never seemed right. Until now.
PADT is pleased to announce that we will be loading furniture and computers in a truck and head on the I-10 to Torrance, California where we will open up a new office. ANSYS, Inc. has expanded our sales territory to include small and medium sized new accounts in the Southern California area. The focus of this new office will be building that business.
You can read the official details in the press release below, or the PDF here. As usual, we want to share some more informal information with our blog readers.
The office will be started with an engineer and a salesperson who have been with us for a while, and another pair that we are hiring locally. This combination of company experience and local knowledge should get us going quickly. Over time, the plan is to grow the Torrance office, and add at least two more. Long term we would like to have between 3 and 10 employees per office in Southern California.
Our team will conduct training and seminars from this office and use it as a base to spread the word on simulation driven product development across Southern California. The initial focus for sales will be on small and medium sized businesses that are currently not using ANSYS products, that want to work with a technical sales and support team who can provide more than the software tool – customers who want a partner who can also help them apply the tools effectively. The dense hotbeds of engineering along the coast will be an obvious area of concentration. We also aim to represent the value of ANSYS products in less visited areas of the region, including the high deserts, “in-between” towns, and inland locations beyond LA, Orange County, and San Diego.
Consumers in the United States spend almost seven trillion dollars each year on consumer goods. In order to tap into this lucrative market, many major american companies in mexico manufacture their products in exotic locales such as China, India, or other Asian nations due to their cheap labor and lax trade restrictions. Unfortunately, few of the industries that export their capitol across the Pacific realize that they could save more money with one short trip across the southern border to the maquiladoras of CaliBaja based in Mexicali, Baja California and Calexico, California.
Because of international trade agreements such as NAFTA, manufacturers can import raw material and heavy equipment into Mexico duty and tariff-free in an arrangement referred to as the maquiladora program. The word maquiladora is derived from the Spanish term that translates to “to submit something to the action of the machine.” The governments of the United States and Mexico developed a mutually beneficial economic partnership that allows American businesses to utilize Mexican labor laws while maintaining production standards and levels found in the best American factories. This agreement has been the secret weapon used by such prominent companies as 3M Corp, General Electric, Boeing, Sanyo, Wolf Electronics, and Page Electric to decrease production costs and increase profits.
CaliBaja is the leading business in the maquiladora program. Clients from across the United States employ CaliBaja in one of two ways: the contract system and the shelter system. The contract system requires the least amount of risk on the client’s part, for it allows them to concentrate on running their business and leave the manufacturing to us. We handle everything else, from quality control, inspection, maintenance, and shipping, to production scheduling, translation, training, and documentation management. Basically, clients tell us what they want to make, we make it, and pass along our expenses as cost. Depending on the volume and type of item desired, clients could save tens of thousands if not hundreds of thousands of dollars.
The shelter system is the fastest way to get a product out the door and to the shelves of retailers. Under this production design, the client provides the equipment, tooling, technical experience, quality control, and management, and we handle the permits, taxes, government interaction, accounting, and legal representation. CaliBaja also ensures that our clients have the finest workforce drawn from the highly motivated and educated population of Mexicali. Furthermore, many clients often find that neither of these solutions fits perfectly with their business needs, so CaliBaja can tailor a program that can suit any manufacturing situation.
Partnering with CaliBaja has several distinct advantages over not only international production but also other maquiladoras in Mexico. First, because we are located next to the U.S.-Mexico border, our clients have more direct control and oversight into their production process, with no time difference commonly experienced during trans-Pacific manufacturing. Furthermore, our facilities are serviced by major rail lines, roads, deep water shipping ports, and airports that can distribute products throughout America and the world. Mexicali is also a prime location for manufacturing, as other border locations such as Tijuana lack both the infrastructure and workforce to properly staff a sophisticated manufacturing program.
The good news is that we are not starting from scratch. This first office is right down the street from the California campus of PADT’s largest and oldest customer. We also have over one hundred customers who have used PADT for simulation services, training, rapid prototyping, and product development, and we will be reaching out to them shortly to start building our local network even further. And then, our new employees who we will hire locally will be contacting their network as well.
Before the end of the summer we hope to have a grand opening event, as well as several seminars that will continue through the end of the year. If you live in the area and want to be invited, visit here to register as someone who want to be on the California contact list.
This blog and social media will be used to post our progress. The entire sales and technical team is looking forward to meeting everyone in the area in the coming months.
If you have any questions or suggestions for us, please contact us. Our standard number 480.813.4884 works for all of our offices.
Below is a copy of the press release, or you can view the “official” version here.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
This week ANSYS, Inc. made a fantastic announcement that has been in the works for a while, and that we think will greatly benefit the simulation community: A free ANSYS Student product. This is an introductory product that is focused on students who are learning the fundamentals of simulation who also want to learn the full power and capability of the ANSYS product suite. It includes ANSYS® Multiphysics™ , ANSYS® CFD™ , ANSYS® Autodyn®, ANSYS® Workbench™, ANSYS® DesignModeler™and ANSYS®DesignXplorer™
Yes you read that right, all of the flagship products for free. No features or capabilities are turned off. It is the exact same software as the commercial product, but the size of problems that you can solve is limited. It runs on MS Windows. Perfect for students.
PADT is excited about this because it gives students access to the ability to learn FEA and CFD simulation with the world’s most popular and capable simulation tool, without running in to brick walls. Want to do a flat plate with a hole in it? No Problem. Want to model fluid-solid-interaction on a flexible membrane valve? No Problem. Want to model explosive forming? No Problem. Want to model combustion with complex turbulence? No problem.
All in the same interface as students will use when they enter the work force or do research at University.
This is great news and we can’t wait to see what schools and students do with this access.
How to Get It – The New Academic Web Pages
The previous Student Portal is being replaced with an Academic Web area on the ansys.com site: ansys.com/academic.
Go to the ANSYS Student site to learn more about ANSYS Student and how to download your copy. These same pages will have resources to help you learn and understand the product.
Let me state categorically that PADT was not consulted on the image that ANSYS, Inc. used for the “student” user that was so happy to find out that there is now a free version of the ANSYS software suite. Here is their picture:
Just kidding. We were happy to see this product come out and thought the picture was hilarious. In all seriousness, we will also plug the recent #ilooklikeanengineer twitter hash tag , highlighting the diversity of female engineers. that was awesome and we would love to see more chances for engineers to show their true selves.
Simulation has revolutionized flow and heat transfer dependent systems over the past decades by minimizing costly physical testing and accelerating time to operation around the world. But for many companies, such simulation has largely focused on components and proved to be very time consuming. The technology advancements delivered by Flownex SE now offer a fast, reliable, and accurate total system and subsystem approach to simulation.
With the release of FLOWNEX 2015, users now have access to advanced combustor system level modeling and they can interact with more system and component simulation tools. This is on top of the already considerable capabilities found in the tool
Gas Turbine Combustor Heat Transfer Library
During the Preliminary design phase or when considering modifications to existing combustor designs it’s essential to make realistic predictions of mass flow splits through the various air admission holes, total pressure losses liner temperatures along the length of the combustor etc.
Although very powerful, 3D CFD solutions of combustors are specialized, time consuming processes and therefore are seldom exclusively used during initial sizing of a combustor.
It has been demonstrated that 1D/2D network tools, like Flownex, are capable of predicting with reasonable accuracy the same trends as more detailed numerical models.
The advantage, however, is Flownex’s rapid execution, which allows design modifications and parametric studies to be conducted more simply than ever before. The ease of use and incredible speed of Flownex allows 1000s of preliminary designs to be evaluated under all modes of operation for steady state and dynamic cases. Furthermore, the data obtained from the one-dimensional analysis can be used as boundary conditions for a more detailed three-dimensional model, ultimately supplementing a typical combustor design work flow.
While the simulation of combustor systems was previously possible in the Flownex environment, much of the work of implementing industry standard heat transfer correlations was left to the user through scripting .Now in Flownex SE 2015 it’s all been built in to the tool, while maintaining the flexibility required to model any combustor configuration.
New components include
- Film convection component
- Fluid radiation component
- Jet impingement heat transfer component
To sum up Flownex allows more accurate initial designs, less time is spent on advanced 3D combustor simulations and rig tests, thus reducing development time and cost.
Here is a Video that shows off these features:
Added importers and integration features
AFT Fathom/Impulse/Arrow importer
An importer was added to import the file formats of AFT products. The importer imports all the diameters, loss factors heights, etc. so 90% of the effort is done, and in some cases the networks solve without any modifications.
ROHR2 Integration (pipe stress analysis software)
Flownex has the ability to calculate forces during dynamic simulations. This is very useful in pipe stress analysis for surge or water hammer cases. The ability to import complete geometries from ROHR2 and export results in the format that ROHR2 expects natively has been added. This means a user can perform these combined analysis now with ROHR2 with the minimum of effort.
An Importer was added to import liquid and gas properties from CoolProp an open source fluid property library. The existing Aspen/Hysys fluid importer was changed to be a generic Cape-Open compliant importer. This means that fluid properties can now be imported from any Cape-Open compliant server software.
It’s not a series of articles until there’s at least 3, so here’s the second article in my series of ‘what not to do’ in ANSYS…
Just in case you’re not familiar with thin sweep meshing, here’s an older article that goes over the basics. Long story short, the thing sweep mesher allows you to use multiple source faces to generate a hex mesh. It does this by essentially ‘destroying’ the backside topology. Here’s a dummy board with imprints on the top and bottom surface:
If I use the automatic thin sweep mesher, I let the mesher pick which topology to use as the source mesh, and which topology to ‘destroy’. A picture might make this easier to understand…
As you can see, the bottom (right picture) topology now lines up with the mesh, but when I look at the top (left picture) the topology does not line up with the mesh. If I want to apply boundary conditions to the top of the board (left picture), I will get some very odd behavior:
I’ve fixed three sides of the board (why 3? because I meant to do 4 but missed one and was too lazy to go back and re-run the analysis to explain for some of future deflection plots…sorry, that’s what you get in a free publication) and then applied a pressure to all of those faces. When I look at the results:
Only one spot on the surface has been loaded. If you go back to the mesh-with-lines picture, you’ll see that there is only a single element face fully contained in the outline of the red lines. That is the face that gets loaded. Looking at the input deck, we can see that the only surface effect element (how pressure loads are applied to the underlying solid) is on the one fully-contained element face:
If I go back and change my thin sweep to use the top surface topology, things make sense:
The top left image shows the thin sweep source definition. Top right shows the new mesh where the top topology is kept. Bottom left shows the same boundary conditions. Bottom right shows the deformation contour.
The same problem occurs if you have contact between the top and bottom of a thin-meshed part. I’ll switch the model above to a modal analysis and include parts on the top and bottom, with contact regions already imprinted.
I’ll leave the thin sweeping meshing control in place and fix three sides of the board (see previous laziness disclosure). I hit solve and nothing happens:
Ah, the dreaded empty contact message. I’ll set the variable to run just to see what’s going on. Pro Tip: If you don’t want to use that variable then you would have to write out the input deck, it will stop writing once it gets to the empty contact set. Then go back and correlate the contact pair ID with the naming convection in the Connections branch.
The model solves and I get a bunch of 0-Hz (or near-0) modes, indicating rigid body motion:
Looking at some of those modes, I can see that the components on one side of my board are not connected:
The missing contacts are on the bottom of the board, where there are three surface mounted components (makes sense…I get 18 rigid body modes, or 6 modes per body). The first ‘correct’ mode is in the bottom right image above, where it’s a flapping motion of a top-mounted component.
So…why don’t we get any contact defined on the bottom surface? It’s because of the thin meshing. The faces that were used to define the contact pair were ‘destroyed’ by the meshing:
Great…so what’s the take-away from this? Thin sweep meshing is great, but if you need to apply loads, constraints, define contact…basically interact with ANYTHING on both sides of the part, you may want to use a different meshing technique. You’ve got several different options…
- Use the tet mesher. Hey, 2001 called and wants its model size limits back. The HPC capabilities of ANSYS make it pretty painless to create larger models and use additional cores and GPUs (if you have a solve-capable GPU). I used to be worried if my model size was above 200k nodes when I first started using ANSYS…now I don’t flinch until it’s over 1.5M
Look ma, no 0-Hz modes!
- Use the multi-zone mesher. With each release the mutli-zone mesher has gotten better, but for most practical applications you need to manually specify the source faces and possibly define a smaller mesh size in order to handle all the surface blocking features.
Look pa, no 0-Hz modes!Full disclosure…the multi-zone mesher did an adequate job but didn’t exactly capture all of the details of my contact patches. It did well enough with a body sizing and manual source definition in order to ‘mostly’ bond each component to the board.
- Use the hex-dominant mesher. Wow, that was hard for me to say. I’m a bit of a meshing snob, and the hex dominant mesher was immature when it was released way back when. There were a few instances when it was good, but for the most part, it typically created a good surface mesh and a nightmare volume mesh. People have been telling me to give it another shot, and for the most part…they’re right. It’s much, much better. However, for this model, it has a hard time because of the aspect ratio. I get the following message when I apply a hex dominant control:
- The warning is right…the mesh looks decent on the surface but upon further investigation I get some skewed tets/pyramids. If I reduce the element size I can significantly reduce the amount of poorly formed elements:
- That’s going on the refrigerator door tonight!
And…no 0-Hz modes!
- Lastly…go back to DesignModeler or SpaceClaim and slice/dice the model and use a multi-body part.
3 operations, ~2 minutes of work (I was eating at the same time)
That’s a purdy mesh! (Note: most of the lower-quality elements, .5 and under, are because there are 2-elements through thickness, reducing the element size or using a single element thru-thickness would fix that right up)
Phew…this was a long one. Sorry about that. Get me talking about meshing and look what happens. Again, the take-away from all of this should be that the thin sweeper is a great tool. Just be aware of its limitations and you’ll be able to avoid some of these ‘odd’ behaviors (it’s not all that odd when you understand what happens behind the scenes).
We just recieved a new tech tip bundle from ANSYS, Inc on Electromechanical Simulation. You may remember when we published the Mechanical and Fluids ANSYS tech tips a few weeks ago. This latest kit continues with information for people making devices and systems that have mechanical and electrical systems. The focus of the kit is the application of ANSYS Maxwell and Simplorer – Maxwell to model low frequency electromagnetics and Simplorer to model systems.
Here is a link to “The Electromechanical Simulation Productivity Kit ” here. The kit includes:
- ANSYS Maxwell Automation and Customization Application Brief
- ANSYS Maxwell Magnetic Field Formulation Application Brief
- Electric Machine Design Methodology Whitepaper
- Electromagnetics And Thermal Multiphysics Analysis Webinar
- Rechargeable Lithium Ion Battery Whitepaper
- Robust Electric Machine Design – ANSYS Advantage Article
We also have a collection of videos that are a great introduction to the tool set and how to use it. Check out the overview and the video on the washing machine at a minimum. Even if you have a simple EMAG or do hand calcs, you need to look at Maxwell and Simplorer.
One way to really unleash the power of APDL is to become familiar, and ultimately fluent, with array parameters. The APDL student will quickly learn that array manipulation involves heavy use of the *V commands, which are used to operate on vectors (single columns of an array). These commands can be used to add two vectors together, find the standard deviation of a column of data, and so on. *V commands consist of what I like to refer to as “action” commands and “setting” commands. The action commands, such as *VOPER, *VFILL, and *VFUN * have their own default behaviors, but these defaults may be overridden by a preceding setting command, such as *VABS, *VLEN, or *VMASK.
*VMASK is one of the most useful, but one of the most difficult to understand, *V command. At its essence it is a setting command that directs the following action command to a “masking” array of true/false values. Only cells corresponding to “true” values in the masking array are considered for the array being operated on in the subsequent action command.
For example, a frequently used application of *VMASK is in the compression of an array—for instance to only include data for selected entities. The array to be compressed would consist of data for all entities, such as element numbers, x-locations for all nodes, etc. The masking array would consist of values indicating the select status for the entities of interest: 1 for selected, –1 for unselected, and 0 for not even in the model to begin with. Only array cells corresponding to a masking array value of 1 would be included in the compression operation, with those corresponding to a value or 0 or –1 being thrown out. Here is a slide from our APDL training class that I hope illustrates things a little better.
What we’ve learned so far is that the masking array contains a list of true/false (or not true) values to refer to when performing its vector operation. But actually, it’s much more general than 1, 0, and –1. What *VMASK does is include cells corresponding to all positive numbers in the masking array (not just +1) and exclude cells corresponding to all values less than or equal to zero in the masking array (not just 0 and -1), which broadens the possibilities for how *VMASK can be handy.
Everything I’ve used *VMASK for up to this point in my career has involved array compression, and I figured I’d be put out on a sweep meshed ice floe into a sea of CFD velocity streamlines (that’s what happens to old CAE engineers; you didn’t know that?) before I came up with anything else. However, I recently ran into a situation where I needed to add up just the positive numbers in an array. I was about to construct an algorithm that would test each individual number in the array to see if it was positive and, if so, add it to the total. It would’ve been cumbersome. Then I came up with a much less cumbersome approach: use the array as it’s own masking array and then perform the addition operation. Let’s look at an example.
Take the following array:
The sum of all values in the array is 1.5 whereas the sum of just the positive values is 11.5. What’s the most efficient way to have APDL calculate each?
In the case of summing all values in the array, it’s easy, just simply execute
which gives you
But what about summing just the positive values? That’s easy, just use SUM_EXMPL as its own masking array so that only the positive values are included in the operation.
Now why was I doing this? I had to create a macro to calculate total nodal loads for an unconstrained component in just the positive direction (to ignore the loads counteracting in the negative direction), and this was my approach. Feel free to download the macro: facelds.mac and try it out yourself.
This video will show you how you can optimize a part using Topology Optimization with GENESIS through ANSYS Mechanical with support from ANSYS SpaceClaim
With the introduction of ACT, the ANSYS Workbench editors have gained capabilities and shortcuts at much faster rate than what can be introduced in a development cycle. One of first and most far-reaching extensions is the acoustics. Inevitably I was called on by one of our customers to show them how to do a vibro-acoustics analysis (harmonic with acoustic excitation), which I did. Since the need for this type of analysis is quite broad, I’ll share it here too.
There was an extra level of excitement with this, in that I’m a structures specialist with no prior acoustics experience. So, I did my own self-training on this topic. I have to give tons of credit to Sheldon Imaoka of ANSYS Inc., who took the time to thoroughly answer the questions I had. That being said, this article will be from the standpoint of a structures engineer who’s just recently learned acoustics.
It’s at the very top, under ‘A’ for “Acoustics”
One thing you’ll notice when you unzip the Acoustics Extension package is that it contains and entire Acoustics training course. Take advantage of this freebie when learning acoustics analysis. I’ll note that, most of the process outlined in this article comes from the Submarine workshop in the acoustics training course.
Once you’ve installed and turned on the Acoustics extension, insert a Harmonic Analysis system into the project schematic, link to the solid geometry file, and specify the material properties for the solid. You’ll specify the properties for the acoustic region in Mechanical under the appropriate Acoustics extension objects.
Rename as you see fit
Assuming you just have the geometry for the solid and not the acoustics domain, create two acoustics regions around the solid. The first region, surrounding the solid, will function as the fluid region itself, through which the acoustic waves travel and interact with the structure. The second region, surrounding the first acoustics region, will function as the Perfectly Matched Layer (PML). The PML essentially acts as the infinite boundary of the system. (If you’re an electromagnetics expert, you already know this and I’m boring you.) You can easily create these domains using the enclosure tool in DesignModeler.
Now we’re ready for the analysis. Open up Mechanical. Look at all those buttons on the Acoustics toolbar! Yikes! Fortunately we just need a few of them.
Here they are
Insert an Acoustic Body and scope it to the acoustic region surrounding the structural solid. In the Details, enter the density and speed of sound for the fluid. Also set the Acoustic-Structural Coupled Body Options to Coupled With Symmetric Algorithm.
Pay attention to the menu picks, Details, and geometry scoping here and in the rest of the image captures
“Coupled” refers to coupled-field behavior, i.e. the mutual interaction between the structure and the fluid. You’re probably familiar with this. You need that, otherwise the acoustic waves are just bouncing off the structure and the structure isn’t doing anything. Regarding the Symmetric Algorithm: The degrees of freedom for the acoustic system consists of both structural displacements and fluid pressures, giving you an asymmetric stiffness matrix. However, ANSYS has incorporated a symmetrization algorithm to convert the asymmetric stiffness matrix to a symmetric matrix, resulting in half as many equations that need to be solved and thus a faster solution time yadda yadda yadda, so go with that.
Now insert another Acoustic Body, this time scoped to the outer acoustic region (body). This is your Perfectly Matched Layer. Specify fluid density and speed of sound as before. This time, leave the Coupled Body Option as Uncoupled. But, set Perfectly Matched Layers to On.
Apply an Acoustic Pressure of zero to the outer faces of the PML body (Boundary Conditions > Acoustic Pressure). As you may have guessed from the menu pick, this is your acoustics boundary condition.
Now we’ll apply some acoustic wave excitation to this thing. From the Excitation menu, select Wave Sources (Harmonic). In the Details, set the Excitation Type to either Pressure or Velocity, set the Source Location and specify the excitation pressure or velocity value. In this example, I went with Pressure since that’s what MIL-STD-810 specifies, but this option will be based on your customer requirements. I also assumed an external acoustic source (hence, Outside the Model), but again, that will be based on your particular project. You also need to specify the vector of the wave source, via rotations about the Z and Y axes (f and q). In this case I chose 30 and 60 degrees, respectfully, to make it interesting. Once again, enter the density and speed of sound for the fluid.
Insert Scattering Controls under the Analysis Settings menu and specify whether the Field Output should be Total or Scattered. Total gives you constant pressure waves that interact with the solid but not each other. Scattered gives you wave that interact and interfere with each other as well as the solid.
Set up the Fluid-Structural Interaction boundary condition where the structural faces are “wetted” by the acoustic domain. The FSI Interface is found under the Boundary Conditions menu.
Apply structural constraints and specify harmonic analysis settings just like you would with a standard harmonic analysis. Make sure you request Stresses under the Output Controls. Solve the model.
Plot your structural results as you would for a typical harmonic analysis. Acoustic Pressure wave results may be found under the Results menu in the Acoustics toolbar. If you used Total field output for the scattering option, you can verify your wave source direction by looking at the Acoustic Pressure Contours. Keep in mind that the contours will be orthogonal to the axis of the sine wave; you may need to put some extra spatial thought into it to fully understand what’s going on.
Acoustic Pressures: Field Output = Total
Acoustic Pressures: Field Output = Scattered
Von-Mises Stresses, Max Over Phase: Field Output = Scattered
As you’ll note in the training course, there are a number of design questions that can be answered with acoustics analysis. In this article, I’ve addressed what I thought would be one of the more popular applications of acoustics simulation. If the demand is there, I’ll research and compose more articles on various acoustics applications in the future. For instance, another area I’ve examined is natural frequencies of a structure that’s submerged in a fluid. If there’s another acoustics topic you’d like us to write about, please let us know in the comments.
ANSYS PExpert is a fantastic tool for the design, modeling, and analysis of transformers and inductors. Using a combination of classical and finite element analysis (FEA) techniques, ANSYS PExprt determines the core size and shape, air gaps, and winding strategy for a given power converter topology. What we and our customers have found very useful is the ability to then evaluate the magnetic design in ANSYS Maxwell to view such things as flux density in the core and current density distribution in the windings. Powerful stuff.
The first step in implementing ANSYS PExprt with ANSYS Maxwell is installing and configuring them correctly. We created a step-by-step guild for our ANSYS customers here in the Southwest, and thought others would find it useful.
This Thursday we had the first of seven free seminars on how to deal with geometry created with 3D scanning, how to repair faceted geometry, and how to deal with old CAD geometry. Don’t panic, we have six more scheduled. Scroll down to see the schedule and register for upcoming versions of this seminar. The inaugural session was held in PADT’s Tempe office and engineers from several departments across the company shared the tools we use in consulting and the lessons we have learned over the years to a pack room full with customers that represented everything from the home inventor to engineers from some of Arizona’s largest aerospace and electronics companies.
As more and more companies do 3D printing we are finding that they struggle with imperfect geometry. Whether it was scanned, from another CAD system, or an STL (3D Printer) file from someone else, when it came time to print parts people were having difficulty getting valid geometry. So we created a road show to go over the tools we use here to 1) get good scan geometry in the first place, 2) convert scan geometry into something useful, and 3) repair bad STL and CAD files.
Things got kicked off with a presentation on the various ways you can scan 3D geometry. Our scanning engineer, Ademola, also demonstrated our Geomagic Capture and Steinbichler scanner on some real parts.
After some food, we moved on to looking at Geomagic Design X. This is the tool we use to convert our scan data to a fully usable and clean CAD model. If you have tried to go from scan to CAD without this tool, you know how much work it is.
Next we looked that the tool that we use to import, modify, and clean existing geometry: SpaceClaim. As the presenter Tyler Smith said “No matter the source of geometry, SpaceClaim is the tool to help”
We finished up with topological optimization. Where we spent most of the event talking about how to get good geometry, in this last presentation we talked about how to make the geometry better by using simulation to optimize the shape of your parts.
It was a great crowd with the kind of questions you hope for when doing a seminar. If you are in the Southwest, there is still time to attend one of these lunch & learns being held in other locations. Click on the event you want to register.
Or you can contact PADT directly to learn more about the products and services we covered, which included:
- Geomagic Capture Scanners
- Steinbichler 3D Scanners
- Geomagic Design X
- ANSYS SpaceClaim
- VR&D GENESIS
- PADT geoCUBE Computers
In a recent press release, PADT Inc. announced the launch of CoresOnDemand.com. CoresOnDemand offers CUBE simulation clusters for customers’ ANSYS numerical simulation needs. The clusters are designed from the ground up for running ANSYS numerical simulation codes and are tested and proven to deliver performance results.
POWERFUL CLUSTER INFRASTRUCTURE
The current clusters available as part of the CoresOnDemand offering are:
1- CoresOnDemand – Paris:
80-Core Intel based cluster. Based on the Intel Xeon E5-2667 v.2 3.30GHz CPU’s, the cluster utilizes a 56Gbps InfiniBand Interconnect and is running a modified version of CentOS 6.6.
2- CoresOnDemand – Athena:
544-Core AMD based cluster. Based on the AMD Opteron 6380 2.50GHz CPU’s the cluster utilizes a 40Gbps InfiniBand Interconnect and is running a modified version of CentOS 6.6.
Five Key Differentiators
The things that make CoresOnDemand different than most other cloud computing providers are:
- CoresOnDemand is a non-traditional cloud. It is not an instance based cluster. There is no hypervisor or any virtualization layer. Users know what resources are assigned exclusively to them every time. No layers, no emulation, no delay and no surprises.
- CoresOnDemand utilizes all of the standard software designed to maximize the full use of hardware features and interconnect. There are no layers between the hardware and operating system.
- CoresOnDemand utilizes hardware that is purpose built and benchmarked to maximize performance of simulation tools instead of a general purpose server on caffeine.
- CoresOnDemand provides the ability to complete high performance runs on the compute specialized nodes and later performing post processing on a post-processing appropriate node.
- CoresOnDemand is a way to lease compute nodes completely and exclusively for the specified duration including software licenses, compute power and hardware interconnect.
CoresOnDemand is backed up by over 20 years of PADT Inc. experience and engineering know-how. Looking at the differentiating features of CoresOnDemand, it becomes apparent that the performance and flexibility of this solution are great advantages for addressing numerical simulation requirements of any type.
Or contact our experts at email@example.com or 480.813.4884 to schedule a demo or to discuss your requirements.
Once ANSYS started doing more regional user group meetings, we here at PADT decided to stay out west where we felt comfortable. So we have only attended the California and Texas events in the past. This year we decided to venture further East and go to the Convergence meeting in Chicago. I have to say it was a great experience, different then the Santa Clara meeting a few weeks ago.
Being from Arizona, I was a bit worried about the weather. It was appropriately windy, and unfortunately overcast with low clouds so my pictures of the famous skyline was a bit stunted.
What was so great was that the same type of smart people who get simulation were there, the products they work on were very different. From train locomotives to exercise equipment to automotive electronics, we were exposed to a variety of very unique and very cool applications. And as usual, the people from ANSYS, Inc. had a lot to contribute and show off that was new or coming in various programs.
The event started off with a great presentation from Sin Min Yap, VP of Marketing at ANSYS, on how simulation can be used to turn good ideas in to great products. Some great customer stories were shared and it really set a foundation as to why we do this thing called modeling and simulation.
However, the customer keynote address stole the show. It was from Jim Kennedy at Mars Corporate Innovation. No, there is no corporation on Mars (outside of SciFi movies). This is the Mars Corporation that is famous for their candy (M&M’s!!!!) and also does several well known pet foods, Wrigley chewing gum, a bunch of food brands, and drinks. His talk was how the manufacturing of food can be improved with simulation. Here is a bad picture of a great slide showing the modeling in FLUENT of their gum Kneaders.
And here is a model of forming Skittles:
For an engineer, it doesn’t get much cooler than that. He had other great examples, and tied it all together to show how they do some very sophisticated simulation to improve their efficiency, product quality while reducing cost and minimizing their energy footprint.
Several of us sitting in the back were just amazed at the complex material models they must be using. Candy, chocolate, gums – much more difficult than stainless steel for sure!
The next speaker talked about the Internet of Things (IoT) and the Industrial Internet, which is the IoT applied to the machines that are used to make things, and to monitor products in the field. My key takeaway is that those of us who are responsible for designing new products have to start figuring out how we are going to make it all work. Simulation can be used to solve difficult packaging issues with batteries, antenna, and sensors the will soon be in most products we develop. And ANSYS has the tools to do the simulation.
ANSYS also talked about their new ANSYS Enterprise Cloud solution. A very impressive effort to do a true Cloud solution for simulation… not just call time-sharing “cloud computing.” Working with Amazon they have introduced a truly scalable, interactive, secure, and robust solution that sets the industry standard for Cloud based simulation. We also got a chance to play with it, because ANSYS’s Judd Kaiser was in the booth next to me. It really is easy to implement and use. I took a picture when Judd was not looking:
Renee Demay, the head of the ANSYS Customer Excellence team explained how ANSYS, Inc. is delivering a new more effective solution for customer support and services – focused as the name says on giving the customer and excellent experience.
And then the morning session finished on my favorite combined topic: Simulation and 3D Printing. John Graham from ANSYS SpaceClaim gave a great talk on how SpaceClaim can be used to improve 3D Printing and serve as the bridge between scanning, 3D Printing, and simulation.
Here he is talking about the repair functionality in the tool. Something we use here at PADT all the time:
That finished up the morning session, which was followed by a nice lunch where we were able to interact with people a lot. Several of you who read this blog stopped by to say hi. That really made my day.
PADT had a booth:
Several of our fiends and partners were also there, so I did a selfie with them all to say hi. First stop was our good friends and fellow ANSYS Channel Partners SimuTech. They have a local office in Chicago:
Right across from them were a team from VR&D, our favorite topological optimization tool:
And NICE was there as well, showing of the remote visualization tool DCV that we use for CoresOnDemand.com and ANSYS uses in EKM and the ANSYS Enterprise Cloud:
The afternoon sessions were great. Lots of ANSYS and customer applications that showed the breadth and depth of usage of ANSYS products in the Midwest.
Then we had a reception, which for a Friday evening where everyone had a big commute ahead of them, was well attended. Wine was drunk, HFSS models were shared, and the best strategy for disk array RAID configuration was debated… among other less interesting things.
A great trip, where I caught up with some old friends and made some new ones. I look forward to exploring further east in the future!
And at least one of us will be in Houston, so if you are going make sure you stop by and say hi!
Personal Note – A Saturday of Frank Lloyd Wright
So instead of trying to red eye it back to Phoenix, I spent the night and on Saturday I went on a pilgrimage I’ve wanted to do some time: a visit to some of Frank Lloyd Wrights early creations. I won’t bore you all with my ineloquent ramblings on what a genius he was. Let me just say it was better than I expected. His studio in his first home was nothing short of amazing (there I go, rambling…) anyhow, here are few shots I took from the outside. I didn’t take any inside pictures because: 1) I take crappy pictures, and 2) I wanted to look and explore instead of take selfies.
The first studio.
The house attached that the studio is attached to. You should see the playroom on the top floor. Here is a link to a great blog posting about the house.
I then went to the Unity Temple which is just down the street. It was covered in scaffolding, but the inside, although worn and in need of repair, was so amazing:
A day well spent.