This Week in CFD

Special Easter Weekend Edition

  • Must read: Now available via the NASA technical reports server is CFD Vision 2030 Study: A Path to Revolutionary Computational Aerosciences.
  • Good advice: How engineers can communicate better (from 3Dconnexion).
  • From the Pointwise newsroom:
    • We released Pointwise V17.2 which extends the T-Rex hybrid meshing technique so that layers of hex cells are created in near-wall and near-wake regions.
    • The Call for Papers is now open for the Pointwise User Group Meeting 2014 to be held 29-30 October in Anaheim, California. Abstracts are due by 18 July.
CFD simulation of automotive paint curing. Simulation and image from Convergent Science.

CFD simulation of automotive paint curing. Simulation and image from Convergent Science.

The Bloodhound supersonic car may truly be the most exciting and dynamic engineering challenge going on today. Judging by this picture from The Economic Times, one of the challenges is 1980s vintage CFD of an airplane flying in a tube. (This is the mainstream media reporting on science.)

The Bloodhound supersonic car may truly be the most exciting and dynamic engineering challenge going on today. Judging by this picture from The Economic Times, one of the challenges is 1980s vintage CFD of an airplane flying in a tube. (This is the mainstream media reporting on science.)

3D Printed Voronoi Polyhedra

I could not pass up this image from Pinterest of work by Michiel Cornelissen of a 3D Voronoi structure done using Grasshopper and MeshMixer for 3D printing.

3D Voronoi structure by Michiel Cornelissen

3D Voronoi structure by Michiel Cornelissen

[Which reminds me that we should really finish tweaking the 3D printing plugin for Pointwise that lets you print your mesh.]

Posted in Software, News, Events, Applications, Hardware | Tagged , , , , , , , , , , , , , , , | Leave a comment

This Week in CFD

The First Heading

  • CRAFT Tech released CRUNCH CFD Version 3.0 with a new flamelet model, mesh adaption and more.
  • The 2nd AIAA Propulsion Aerodynamics Workshop will be held prior to this summer’s Joint Propulsion Conference in Cleveland, Ohio. The CFD test cases are available for download (registration required).
  • CGNS, the CFD data standard for portable and interoperable grid and flow solver data, is an AIAA recommended practice as well as an ANSI standard. An updated version of CGNS’ SIDS (standard interface data structures) is up for review and comment through 16 May.
  • Desktop Engineering writes about CAE simulation of arterial stents including CFD with STAR-CCM+.
CFD simulation of flow through a blood vessel with a stent by STAR-CCM+. Image from Desktop Engineering.

CFD simulation of flow through a blood vessel with a stent by STAR-CCM+. Image from Desktop Engineering.

The Second Heading

Flow visualization from FieldView for Concordia University's entry for the SAE Supermileage Competition. Image from Intelligent Light.

Flow visualization from FieldView for Concordia University’s entry for the SAE Supermileage Competition. Image from Intelligent Light.

The Third Heading

  • Scuderia Toro Rosso is looking to hire a CFD Aerodynamicist for F-1 work in the UK.
  • The Imperial College of London has an opening for a PhD studentship in high-order grid generation for CFD.
  • OpenBoundaries is looking for volunteers to test their “remote CAD on demand.”
  • Converge CFD is now available in the cloud via Rescale. [I can't remember whether I posted this already or not so forgive the possible duplication.]
  • Two eye-catching videos:
    • Realflow high viscosity chocolate test
    • XFlow simulation of an UCAS landing on an aircraft carrier
Mmmm. Chocolate. Screen capture from a video of a Realflow simulation.

Mmmm. Chocolate. Screen capture from a video of a Realflow simulation.

At Least It’s Not Paint

I promised to never post another photograph of thrown, spilled or tossed paint. So here’s one of sand from Claire Droppert’s series called Sand Creatures in which she seeks to “capture earth’s different elements and let them stand out in their natural surroundings using moments of zero gravity.”

capture earths different elements and let them stand out in their natural surroundings using moments of zero gravity.
Read more at http://www.visualnews.com/2014/03/23/sand-creatures-claire-droppert-captures-clouds-sand-mid-flight/#Me0xrf8fF5m2JL7R.99c
capture earths different elements and let them stand out in their natural surroundings using moments of zero gravity.
Read more at http://www.visualnews.com/2014/03/23/sand-creatures-claire-droppert-captures-clouds-sand-mid-flight/#Me0xrf8fF5m2JL7R.99
Sand Creatures by Claire Droppert

Sand Creatures by Claire Droppert

P.S. The headings are not a mistake. I simply wasn’t inspired to organize the links today.

P.P.S. My original “back page” article got too long so I’ll spin it off as its own post for next week. Sorry about the sand.

Posted in Applications, Events, Hardware, News, Software | Tagged , , , , , , , , , , , , , , | Leave a comment

9th Annual OpenFOAM Workshop

Pointwise will be participating in the upcoming OpenFOAM workshop hosted in Zagreb, Croatia from June 23 – 26, 2014. The flexibility of OpenFOAM provided a great platform to carry out a number of simple grid studies, and I will be presenting work intended to shed light on quantitative effects of poor grid quality on the accuracy of a solution. In essence, I am intentionally constructing bad grids to see what happens to the solution and which types of grid flaws have the greatest effect on solution accuracy.

Types of grid anomalies being investigated include flow alignment, skewness (both aligned and misaligned with the flow), volume ratio, grid line angle continuity, etc. The computations are being performed using OpenFOAM, but the goal is to find trends that should be similar across many different finite volume codes. Eventually, these studies will be expanded to include a wide array of different solvers. The idea is to isolate each type of shortcoming and quantify its effect on the cumulative error of the solution.

Quad grid

Figure 1 – A ‘worst case’ grid was constructed that has skewness, flow-misalignment and discontinuities in gridline angle.

The work is currently on-going, but I’ll leave you with a worst-case scenario that was intended to be a poor quality grid. A structured grid was made using Pointwise such that every gridline in the direction of the flow formed a regular zigzag pattern, as seen in Figure 1. When the solution was calculated on this grid, the maximum error introduced to the solution was on the order of 10%, as seen in Figure 2. Moral of the story, don’t make structured grids that look like disorienting wall-paper.

Figure 2 – Error between the exact solution and the solution calculated on the grid from Figure 1 shows significant errors arising from the poor grid quality. (Any color other than green is bad.)

Figure 2 – Error between the exact solution and the solution calculated on the grid from Figure 1 shows significant errors arising from the poor grid quality. (Any color other than green is bad.)

Interestingly, if we diagonalize those skewed quad cells, the resulting mesh is a nearly perfect triangular mesh as seen in Figure 3, and the solution (using the same solver settings) shows negligible error as demonstrated in Figure 4.

Tri grid

Figure 3 – Diagonalizing the domain results in a nice uniform triangular mesh.

Solution error

Figure 4 – The unstructured 2D mesh has negligible error.

I’ll be showing these results and other test cases that attempt to isolate the various grid contributors to overall solution error. If you have any suggestions for other grid attributes to investigate not mentioned above, please drop me a line. I hope you will be able to attend the workshop to ask questions and add your experiences of grid quality affecting solution accuracy and convergence. Vidimo se tamo!

Posted in Applications, Events, People & Places | Tagged , , | Leave a comment

How Pointwise Uses Social Media

The fact that you’re reading this tells me you know something about social media. Otherwise, why would you be reading a blog?

At Pointwise we’re trying to make the best use of social media to share information with people worldwide who are interested in CFD and mesh generation. In general, we view social media as a convenient method of engaging people in a conversation. At the top of this web page you’ll find a resource page of other companies and people using social media for CFD.

We have also seen a few technical support issues raised on Facebook and Twitter as opposed to conventional support forums like email or our website. Times they are a-changin’, especially for those of us who can remember when email was new.

The challenge with social media is figuring out which channel to use and how best to use it. There are also the obvious issues with how specific social channels are optimized for specific types of content – text, image, video.

Let’s face it – Facebook is not the Journal of Computational Physics so we’re not going to use it as such. Twitter only gives you 140 characters to work with so mostly you’re going to get a link to something.

So what exactly are we using these social media platforms for?

sm_Pinterest_20X20Pinterest is the most recent addition to Pointwise’s social media portfolio. You’ll find there a collection of pictures from our newsletter, grids we’ve generated, and other imagery. www.pinterest.com/pointwise

sm_LinkedIn_20X20On LinkedIn we post articles about upcoming events like training courses and webinars. We also mirror posts from our blog. www.linkedin.com/company/pointwise-inc.

sm_Facebook_20X20We use Facebook as a forum to share a more personal look at what’s going on here at Pointwise with updates about our people, places they visit, and people who visit us. www.facebook.com/pointwise

sm_Twitter_20X20Pointwise and some of our staff are very active on Twitter. Not only do we post about the usual things – conferences, courses, software releases – but we also share and retweet interesting news from the CAE world. We try to participate in the weekly #SimulationFriday event in which people from around the globe post images of simulations in work or recently completed. twitter.com/pointwise

sm_Another_Fine_Mesh_20X20You obviously already know about our blog, Another Fine Mesh. Here we try to post articles, some long, some short, about interesting topics in CFD. These posts can include notes about our products, summaries of conferences we attend, news items, and the results of interesting projects we have going on. Each week we write a post called This Week in CFD in which you can find summaries and commentary on notable news items from around the CAE industry. blog.pointwise.com

sm_YouTube_20X20YouTube is our home for video content ranging from recordings of our webinars, demonstrations of how to build meshes, and quick “how-to” style instructions. www.youtube.com/user/CFDMeshing

sm_YPlus_20X20While not strictly a social medium, we turned the Y+ Calculator on our website into an app for iOS and Android mobile devices. Remember all those times you were out on the town and wanted to compute wall spacing to achieve a desired y+? There’s an app for that. www.pointwise.com/yplus

sm_GitHub_20X20 You might call this social meshing. We use GitHub to host our Glyph Script Exchange where you can find Glyph scripts that make Pointwise do things it wasn’t designed to do. This includes macros, templates, command extensions, and sometimes just toys.  pointwise.github.io

sm_The_Connector_20X20The Connector is our email newsletter. Every other month you get an issue with product news, application stories, and related content. We also use The Connector to announce product updates and events. www.pointwise.com/theconnector

We’d like to learn what you think about the intersection of CFD and social media. Maybe you have tips on other social channels we should consider.

  • We hear that Google+ is becoming more and more popular. Should we use it?
  • Should we expand our use of GitHub? We have ideas for other content we can share.
  • Is there something up-and-coming that we should evaluate?

Join the conversation by emailing blog@pointwise.com or commenting on this post.

Posted in Uncategorized | Tagged | Leave a comment

This Week in CFD

Business

  • If you’re interested in the state of the Russian MCAD market, a bilingual research paper is available from Ralph Grabowski, editor of upFront.eZine.
  • Two perspicuous posts from MonicaSchnitger:
    • Exa had a good Q4 rounding out a good 2014. Revenue was up 12% to $54.5 million of which $44.6 million was license revenue (up 8%). The forecast for 2015 includes double-digit license growth. Regarding the needs of their automotive customers Exa stated “regulatory changes are forcing them to get more accurate, more realistic simulation capabilities.” [Because Exa is, to my knowledge, the only publicly traded, purely CFD company, we should all be interested.]
    • Materialise, the company behind the Magics software for CAD-STL conversions and manipulations, is preparing apparently for an IPO. Their 2013 sales totaled 68.7 million euros, a 16% increase relative to the prior year. [Because 3D printing is so closely coupled to meshing, I'm interested.]
  • It was announced that NUMECA is now an official supplier to Oracle Team USA for the America’s Cup.
  • Metacomp Technologies’ CFD++ software will now be distributed in the UK by CFD Technologies. [Disclosure: CFD Technologies also distributes Pointwise.]
This image from Sail World relates to Oracle Team USA's use of NUMECA.

This image from Sail World relates to Oracle Team USA’s use of NUMECA.

Meshing and Other Stuff

  • Desktop Engineering asked the question “How can novice users determine whether the mesh model is good enough?” In their article Meshed up or Messed up? you can read several opinions. [Disclosure: One of those opinions is mine.]
  • Convergent Science announced that their CONVERGE User Group Meeting 2014 will be held in Madison, WI on 23-25 September.
  • AeroDynamic Solutions published the March 2014 issue of The Flow, their newsletter for turbomachinery designers.
This tweet from #SimulationFriday made the art lover in me very happy. I cannot find the original image source. (If you're on Twitter you need to follow the #SimulationFriday hashtag.)

This tweet from #SimulationFriday made the art lover in me very happy. I cannot find the original image source. (If you’re on Twitter you need to follow the #SimulationFriday hashtag.)

Applications

  • This season’s rule changes in Formula 1 have challenged car designers to do more with less. Here’s a video from Ferrari about aerodynamics and CFD.
  • The naval architects at Robert Allan Ltd. have expanded their CFD capabilities.
  • From ENGINEERING.com comes this CFD study using STAR-CCM+ of pipe erosion caused by particle impingement.
  • From CFD Apps comes this slide deck with tips on conducting an aerodynamic vehicle study.
  • The University of New South Wales uses Fluent to improve the aerodynamics of their vehicle for the World Solar Challenge.
Fluent CFD simulation of a crosswind situation for the Sunswift entry in the World Solar Challenge. Image from the Leap CFD blog.

Fluent CFD simulation of a crosswind situation for the Sunswift entry in the World Solar Challenge. Image from the Leap CFD blog.

Software

In Any Other Carafe Would Tap Water Taste the Same?

In order to encourage the consumption of tap (as opposed to bottled) water it was decided to emphasize the quality of water through the design of glass carafes. This project, named Transparente, combines fluid properties (altitude, temperature, hardness, conductivity, pH), Italian artistic flair, and plenty of geometric design using Rhino.

Transparente: glass carafes sculpted to represent water quality. Image from the MecSoft blog.

Transparente: glass carafes sculpted to represent water quality. Image from the MecSoft blog.

 

Posted in Applications, Events, News, Software | Tagged , , , , , , , , , , , , , | 2 Comments

This Week in CFD

Mesh pattern applied to the Stanford bunny in Meshmixer for 3D printing.

Mesh pattern applied to the Stanford bunny in Meshmixer for 3D printing.

  • Autodesk Meshmixer has new 3D printing capabilities such as patterning.
  • Lloyd’s Register has an opening for CFD Principal Specialist.
  • In the wake of CD-adapco’s STAR Global Conference…
    • Want to feel like you were there? Check out the photo gallery.
    • Read CD-adapco‘s own summary of the event. (The 2015 event will be in San Diego.)
    • ENGINEERING.com wrote about the STAR-CCM+ product strategy. (FEA is coming in 2015.)
    • EVP Bill Clark‘s video interview on YouTube gives great insight into the company. (ANSYS Fluent & CFX and OpenFOAM are their two main competitors.) [Bill is one of the good guys in CFD. He is worth knowing.]
  • Rhino users might want to get the new Android-based ViewER for viewing 3DM files.
  • For those of you interested in GPU programming, NVIDIA announced their GPU roadmap.
  • Here’s a brief case study of how JAXA uses Femap for their FEA analyses.
  • And here’s simulation of wave impact on submarines.
CFD simulation of wave impact loading on a submarine hull. Simulation by the Naval Surface Warfare Center. Image from ENGINEERING.com.

CFD simulation of wave impact loading on a submarine hull. Simulation by the Naval Surface Warfare Center. Image from ENGINEERING.com.

One Mesh, Two Mesh, Red Mesh, Blue Mesh

Artist Michael Sandstrom writes “My artwork explores how camouflaged political controls filter our understanding of history and relinquish our ability to accurately observe and respond to current socio-political events.”

Michael Sandstrom, Red Mesh, 2006

Michael Sandstrom, Red Mesh, 2006

Posted in Software, News, Applications, Hardware | Tagged , , , , , , , , | 1 Comment

This Week in CFD

Watch

Screen capture from a video illustrating a FLOW-3D solution of Combined Sewer Overflow. Image from Flow Science.

Screen capture from a video illustrating a FLOW-3D solution of Combined Sewer Overflow. Image from Flow Science.

See

Buy*

  • ESI’s financial results as commented upon by Monica Schnitger look good and the income from OpenCFD and CyDesign appears to be in the 1 million euro range. One factoid that caught my eye is that ESI’s top 20 clients account for 46% of their revenue while for ANSYS that percentage is only 5%.

Read

  • The March 2014 issue of DEVELOP3D is 100 pages of 3D printing goodness.
  • On a related note, Scan&Solve for Rhino now supports 3D printing materials for your simulations.
  • The SolidWorks World 2014 proceedings are now available online including CFD and simulation topics.
  • From Aerospace America comes Ready, Set, Export (PDF) on the pending changes to export regulations for defense related articles (i.e. ITAR and AECA). [IMO, the changes described are good but only the first steps required to make export regulations less burdensome while also providing the desired protections.]
  • In the article Closing the CAD to CAE Gap, we read about how several organizations are moving more and more simulation from dedicated analysts to designers. For example, Northrop Grumman reports that the ratio of designers to analysts has changed over the years from 6:1 to 1:1.2. In other words, everyone’s doing simulation.
  • The secrets of CFD are revealed on the Secrets of Science website with their Introduction to CFD.
This image id described by The Secrets of Sciences as a Fluent solution on a polyhedral mesh for a Formula 1 car.

This image id described by The Secrets of Science as a Fluent solution on a polyhedral mesh for a Formula 1 car.

Use

  • At the STAR Global Conference, CD-adapco president Steve MacDonald announced that over the next year they’ll be adding FEA to STAR-CCM+.
  • AeroDynamic Solutions released ADS Release 6.0 for turbomachinery CFD.
  • Design World shares three free CAD programs for engineers: IronCAD COMPOSE, AutoCAD Inventor Fusion, and Solid Edge 2D Drafting. [I know there are others. Please include your favorite in the comments.]

Apply

  • From Today’s Medical Developments comes news that Menges Roller won an award for their use of CFD to design heat transfer rollers.
  • Build2Design is a new service for ship builders to ensure that their ships perform as designed. Even though optimized using CFD during the design phase, there can actually be wide performance differences in the as-built products.
  • The University of Oslo has an opening for a PhD Research Fellow in fluid mechanics.

The Grids of Agnes Martin

How can engineers not like the work of Agnes Martin? After all, imagine the reams of green quadruled graph paper we’ve all used during the course of our careers. Engineers will also probably be the first to dismiss her work with the cliché “I could do that” retort.

As Agnes Martin said, her paintings have nothing to do with geometry. They’re about finding perfection which can only be found by reading between the lines. Keep in mind that she was strongly influenced by the same desert southwest landscapes that also influenced Georgia O’Keeffe. The amazing comparison there is how the two painters expressed that influence so differently on canvas.

Agnes Martin, Leaf, 1965

Agnes Martin, Leaf, 1965

P.S. If “you can do that,” I really, really wish you would.

*Buy is not a recommendation, just wordplay. You don’t want stock tips from me.

Posted in Applications, Events, News, Software | Tagged , , , , , , , , , , , , , | 1 Comment