As Computational Fluid Dynamics (CFD) remains one of the most flexible and accurate tools for developing solutions involving fluid flows in a variety of industries, it is important of engineers to stay up to date on the software that makes it all possible: ANSYS.
Thanks to the latest version ANSYS Fluent, engineers now more than ever, can generate unexpected insights and additional value, helping to greatly improve the effectiveness of their product development process.
Join PADT’s CFD Team Lead Engineer, Clinton Smith, for a live webinar, covering the various improvements and enhancements made to the Fluent tool in ANSYS 18.2.
By attending this webinar, you will learn how Fluent 18.2 can help users to:
- Define a scalar transport equations to improve results for chemical species
- Visualize injection position and orentation during model setup
- Accurately predict cavitation in high pressure devices with non-condensable gases
- And much more!
Don’t miss your chance to attend this upcoming event,
click below to secure your spot today!
If this is your first time registering for one of our Bright Talk webinars, simply click the link and fill out the attached form. We promise that the information you provide will only be shared with those promoting the event (PADT).
You will only have to do this once! For all future webinars, you can simply click the link, add the reminder to your calendar and you’re good to go!
The A in PADT actually stands for Analysis. Back in 1994 when the company was started, computer modeling for mechanical engineering was called Analysis. It was such an important part of what we wanted to achieve that we put it in the name. Unfortunately, Analysis was a bit to generic so the industry switched to Numerical Simulation, or simply simulation. In the 23 years since we started, analysis… sorry, simulation, has been not just a foundation for what PADT does for our customers, it has become a defacto tool in product development. Through it all there has been a dedicated group here that is focused on providing the best simulation as a service to customers around the world.
Driving Designs with Simulation
Many companies know about PADT with regards to simulation because we are an ANSYS Elite Channel Partner – selling and supporting the entire suite of ANSYS simulation tools in the Southwestern US. The success of simulation in the design and development of physical products is a direct result of the fact that these fantastic tools from ANSYS can be used to drive the design of products. This can be done in-house by companies designing the products, or outsourced to experts. And that is where PADT has come in for hundreds of customers around the world. The expertise we use to support and train on ANSYS products derives directly from our real world experience providing CFD, structural, thermal, electromagnetic, and multiphysics simulations to help those customers drive their product development.
For those not familiar with simulation, or who only use the basic tools embedded in CAD software as a quick check, understanding why it is so important hinges on understand what it really is. Numerical Simulation is a methodology where a physical product is converted into a computer model that represents its physical behavior. This behavior can be many different physics: stresses, vibration, fluid flow, temperature flow, high frequency electromagnetic radiation, sloshing of liquids, deformation during impact, piezoelectric response, heating from static electromagnetic waves, cooling from air flow. The list goes on and on. Pretty much anything you studied in physics can be modeled using a numerical simulation.
The process of doing the simulation consists of taking the physical object and breaking it into discrete chunks, often very small relative to the size of the object, so that equations can easily be written for each chunk that describes the physical behavior of that chunk relative to the chunks around it. Imagine writing equations for the fluid flow in a complicated valve housing, very hard to do. But if you break it up into about one million small polyhedrons, you can write an equation for flow in and out of each polyhedron. These equations are then assembled into a giant matrix and solved using linear algebra. That is why we need such large computers. We mostly use the world’s leading software for this, from ANSYS, Inc.
More than Building and Running Models
Knowing how to build and run finite element and CFD models is key to providing simulation as a service. PADT’s team averages over 18 years of experience and few people come close to their knowledge on geometry preparation, meshing, setting up loads and boundary conditions, leveraging the advantages of each solver, and post processing. That is a good starting point. But what really sets PADT apart is the understanding of how the simulation fits into product development, and how the information gathered from simulation can and should be used. Instead of providing a number or a plot, PADT’s experienced engineers deliver insight into the behavior of the products being simulated.
How each project is conducted is also something that customers keep coming back for. Nothing is ever “thrown over the wall” our passed through a “black box.” From quote through delivery of final report, PADT’s engineers work closely with the customer’s engineers to understand requirements, get to the heart of what the customer is looking for, and deliver useful and actionable information. And if you have your own in-house simulation team, we will work closely with them to help them understand what we did so they can add it to their capabilities. In fact, one of the most popular simulation services offered by PADT is automation of the simulation process with software tools written on top of ANSYS products. This is a fantastic way to leverage PADT’s experience and knowledge to make your engineers more efficient and capable.
Unparalleled Breadth and Depth
Based on feedback from our customers, the other area where PADT really stands out is in the incredible breadth and depth of capability offered. Whereas most service providers specialize in one type of simulation or a single industry, more than twenty years of delivering high-end simulation to evaluate hundreds of products has given PADT’s team a unique and special level of understanding and expertise. From fluid flow in aerospace cooling systems to electromagnetics for an antenna in a smart toy, a strong theoretical understanding is combined with knowledge about the software tools to apply the right approach to each unique problem.
No where is this breadth and depth exemplified than with PADT’s relationship with ANSYS, Inc. Since the company was founded, PADT engineers have worked closely with ANSYS development and product management to understand these powerful tools better and to offer their advice on how to make them better. And each time ANSYS, Inc. develops or acquires a new capability, that same team steps up and digs deep into the functionality that has been added. And when necessary, adding new engineers to the team to offer our customers the same expert access to these new tools.
The best way to understand why hundreds of companies, many of them large corporations that are leaders in their industry, come to PADT from around the world for their simulation services needs is to talk to us about your simulation services needs. Regardless of the industry or the physics, our team is ready to help you drive your product development with simulation. Contact us now to start the discussion.
If you do CFD simulations then you know the struggle that is involved in meshing. It is a fine balance of accuracy, speed, and ease of set up. If you have complex geometry, large assemblies, or any difficulty meshing then this blog article is for you.
Why should I spend time making a good mesh?
The mesh is arguably one of the most important parts of any simulation set up. A good mesh can solve significantly faster and provide more accurate results. Conversely, a poor mesh can make the simulation have inaccurate results and be slow to converge or not converge at all. If you have done any simulation then you know that hitting the solve button can feel like rolling the dice if you don’t have a robust meshing tool.
When is it going to matter?
A good mesh is going to matter on a Friday afternoon when you need to get the simulation started before you leave for the weekend because it takes two days to run and you need to deliver results on Monday but you are up against the clock because you have to get to your kid’s soccer game by 5pm and the mesh keeps crashing.
A poor mesh can do more than just reorganizing you’re social agenda. A poor mesh can drastically change results like pressure drop in an internal flow passage or drag over a body. If you go into that meeting on Monday and tell your boss that the new design is going to perform 10% better than the previous design – you need to be confident that the design is 10% better not 10% worse.
What should I do when I need to create a good mesh?
If you’re the poor soul reading this on a Friday afternoon because you are trying to frantically fix you’re mesh so you can get your simulation running before the weekend – I pity you. Continue reading for my proprietary step by step approach titled “How to get you’re CFD mesh back on track!” (Patent pending).
Step 1) Know your tools
ANSYS has been developing its meshing technology since the beginning of time (not really but almost) – it’s no surprise that its meshing algorithms are the best in the business. In ANSYS you have a large number of tools at your disposal, know how to use them.
The first tool in your toolbox is the ANSYS automatic meshing technology. It is able to predictively apply settings for your part to get the most accurate automatic mesh possible. It has gotten so good that the automatic mesh is a great place to start for any preliminary simulations. If you want to get into the details, ANSYS meshing has two main groups of mesh settings – Global Meshing Parameters and Local Meshing Parameters. Global mesh parameters are great for getting a good mesh on the entire model without going into detailed mesh settings for each part.
But when you do have to add detailed meshing settings on a part by part basis then local mesh settings won’t let you down.
Step 2) Know your physics
What is your primary result of interest? Drag? Pressure drop? Max velocity? Stagnation? If you can quantify what you are most interested in then you can work to refine the mesh in that region so as to capture the physics accurately. ANSYS allows you set local sizing parameters on bodies, faces, lines, and regions which allow you to get the most accurate mesh possible but without having to use a fine mesh on the entire part.
Step 3) Know your mesh quality statistics
Mesh quality statistics can be a good way to gauge the health of your mesh. They are not a foolproof method for creating a mesh that will be accurate but you will be able to get an idea of how well it will converge. In ANSYS meshing there is a number of mesh quality statistics at your fingertips. A quick and easy way to check your mesh is to look at the Minimum Orthogonal Quality statistic and make sure it is greater than 0.1 and Maximum Skewness is less than 0.95.
Step 4) Know your uncertainty
Every test, simulation, design, process etc… has uncertainty. The goal of engineering is to reduce that uncertainty. In simulation meshing is always a source of uncertainty but it can be minimized by creating high quality meshes that accurately model the actual physical process. To reduce the uncertainty in meshing we can perform what is called a mesh refinement study. Using the concept of limits we can say that in the limit of the mesh elements getting infinitely small than the results will asymptotically approach the exact solution. In the graph below it can be seen that as the number of elements in the model are increased from 500 – 1.5million the result of interest approached the dotted line which we can assume is close to the exact solution.
By completing a mesh refinement study as shown above you can be confident that the mesh you have created is accurately capturing the physics you are modeling because you can quantify the uncertainty.
If you currently just skip over the meshing part of your CFD analysis thinking that it’s good enough or if your current meshing tool doesn’t give you any more details than just a green check mark or a red X then it’s time dig into the details of meshing and start creating high quality meshes that you can count on.
If you still haven’t figured out how to get your mesh to solve and its 5pm on Friday see below*
*Common pitfalls and mistakes for CFD meshing:
- Choose your turbulence model wisely and make sure your mesh meets the quality metrics for that model.
- Make sure you don’t have boundary conditions near an area of flow recirculation. If you are getting reverse flows at the boundary then you need to move your boundary conditions further away from the feature that’s causing the flow to swirl in and out of the boundary.
The Speed of Simulation – with Velox Motorsports
With thoroughly engineered components including the use of Finite Element Analysis (FEA), thermodynamics, heat transfer, and Computational Fluid Dynamics (CFD), PADT Startup Spotlight Velox Motorsports strives to produce aftermarket parts that can effectively outperform the factory components.
Join Velox Co-Owners Eric Hazen and Paul Lucas for a discussion on what they use ANSYS simulation software for and how they have benefited from it’s introduction into their manufacturing process.
This webinar will focus on two projects within which the engineers at Velox have see the impact of ANSYS, including:
Using Finite Element Analysis (FEA) to reverse engineer a Subaru fork, find the cause of failure and develop an improved replacement part.
Using Computational Fluid Dynamics (CFD) to rub a shape sensitivity study on Nissan GT R strakes, and develop a replacement that increases down-force without significantly increasing drag.
In support of the ANSYS Startup Program, PADT is proud to introduce the PADT Startup Spotlight.
We here at PADT are firm believers in the opinion that today’s startup companies are tomorrow’s industry leaders and thus should be give every possible opportunity to thrive and succeed.
As a result we are offering full access to our promotional capabilities in order to help startup companies developing physical prototypes to grow and develop in a competitive environment.
We will look through those startups that have purchased the ANSYS Startup Package through PADT, and select one to feature and promote, that we believe clearly represents the drive and entrepreneurial spirit that is key in order to succeed in today’s day and age.
Presenting the first Startup Spotlight:
Since their inception in 2014, Velox Motorsports has always been focused on speed; whether that be the speed of the NASCAR teams they have worked with or the desire their customers have for speed, which drives their competitiveness and fuels the demand for their products.
They even show a passion for speed in the company’s name (Velox), which translates from Latin to “swift or speed”.
Visit www.padtinc.com/startupspotlight for more information on Velox Motorsports and The PADT Startup Spotlight.
One of the cool new features in CFX 18 is the ability to actively review results while the calculation is running. It is supported for steady state and transient calculations, and now includes support for rotating reference frames as well.
What follows are some tutorial-esque steps to get you started.crm_10275-active-solution-monitoring-CFDPostR18
If you have used or are using CFD tools like ANSYS Fluent or ANSYS CFX, then you already know how much of a pain extracting the fluid volume can be from a CAD model. Whether the extraction fails because of geometry issues, or if you’ve forgotten to create capping surfaces for all your openings it can be quite frustrating when you get the “non-manifold body” error.
We’ve done it the same way for a long time – create some super solid and do a Boolean subtract or try to close everything off and try to use a cavity function to fill in the model. Both can have headache inducing issues.
CLICK HERE for a PDF that shows how ANSYS SpaceClaim uses a different approach which can make the fluid volume extraction much easier for engineers.
CLICK HERE for a video demo of this as well
Joining Two of PADT’s Favorite Things: Simulation and 3D Printing
Recent advances in Additive Manufacturing (3D Printing) have removed barriers to manufacturing certain geometry because of constraints in traditional manufacturing methods. Although you can make almost any shape, how do you figure out what shape to make. Using ANSYS products you can apply topological optimization to come up with a free-form shape that best meets your needs, and that can be made with Additive Manufacturing.
A few months ago we presented some background information on how to drive the design of this type of part using ANSYS tools to a few of our customers. It was a well received so we cleaned it up a bit (no guarantee there all the typos are gone) and recorded the presentation. Here it is on YouTube
Let us know what you think and if you have any questions or comments, please contact us.
Vibration induced by vortices in off shore oil rigs are a significant area of concern, and understanding them is a major area of research. In this paper, PADT’s Clinton Smith, PhD, and Tyler Smith are joined by Lubeena Rahumathulla from ANSYS, Inc. to describe how they used ANSYS FLUENT to model this situation. Get the paper here: proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleid=2465497
The design of semi-submersible platforms for offshore oil and gas operations requires an iterative process between early-stage design, numerical simulation, measurements, and full-scale design. Early stage designs are evaluated using numerical simulations, which are typically validated using measurements of a scaled model tested in a wave tank. Full-scale semi-submersibles present a unique challenge, because of the sheer size of the structure. Since VIV measurements of full scale structures are not possible, numerical simulation plays an important role for evaluating vortex-induced vibration (VIV) effects in the appropriate physical regime. The quantification of error in numerical simulation results is limited to verification-type studies, in which the error is reduced by converging the solution on the computational grid. The importance of grid convergence studies in this field cannot be understated, since it is the only way to judge solution accuracy in the absence of measurement data at the full scale. In this paper, a method for a grid convergence study of vortex-induced vibration (VIV) of a model scale semi-submersible platform is presented, in which solutions are obtained using the ANSYS Fluent CFD solver. Five levels of grid refinement are used, with the finest mesh acting as the reference solution for the coarser four levels. Qualitative results of vorticity, pressure and Q-criterion (vortex identification) are presented. Quantitative results such as the nominal amplitude (A/D) of the sway motion are used for judging the convergence of the solution as the grid is refined.
This video shows a really quick and easy way to extract a fluid domain from a structural model without having to do any Boolean subtract operations.
We have been talking a lot about ANSYS AIM lately. Mostly because we really like ANSYS AIM and we think a large number of engineers out there need to know more about it and understand it’s advantages. And the way we do that is through blog posts, emails, seminars, and training sessions. A new tool that we have started using are “Resource and Productivity Kits,” collections of information that users can download.
Earlier in the year we introduced several kits, including ANSYS Structural, ANSYS Fluids, and ANSYS ElectroMechanical. Now we are pleased to offer up a collection of useful information on ANSYS AIM. This kit includes:
- “Getting to know ANSYS AIM,” a video by PADT application engineer Manoj Mahendran
- “What I like about ANSYS AIM,” a video featuring insights on the tool
- Six ANSYS AIM demonstration videos, including simulations and a custom template demonstration
- Five slide decks that provide an overview of ANSYS AIM and describe its new features
- An exclusive whitepaper on effectively training product development engineers in simulation.
You can download the kit here.
Watch this blog for more useful content on AIM in the 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 email@example.com. 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…)
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.