Wednesday, November 28, 2007

HVAC designers should be using Upfront CFD everyday!?!

Seems logical, right? What other industry deals primarily in air flow and thermal management? A typical HVAC designer/engineer spends his time sizing duct work, fans/blowers and attempting to evenly cool or heat large areas. Seems like a no brainer that they would be using Upront CFD. They certainly have the need. But, in fact, it is not commonly used in this industry.

There are many guys/gals in this industry that have a tremendous amount of experience and designs are based on rules of thumb etc. I did a bit of this back in the day in the nuclear world and was priviledged to use a "ductometer". So, in general, it has worked up to this point. Unfortunately, it has worked at a cost. Units are often under and over sized, which results in high utility costs. Not to mention the impact on the environment. Flow straighteners are used in a pinch. The cost of retro-fitting existing designs can be tremendous. So, why isn't Upfront CFD being used?




I think there are many reasons. Primarily, I think that the traditional CFD tools are too expensive, too complicated and are quite frankly, just overkill. The Upfront CFD market has been primarily targeted to folks that are driving MCAD (Pro/e, SW, Inventor etc) tools. HVAC guys are designing in 3D, but are probably using AutoCAD and MicroStation. They actually have access to 3D CAD files via an SAT output from AutoCAD, but it can be clunky.

Times are changing. Many architectural firms running AutoCAD are being exposed to Inventor. Believe it or not, Rhino is popular in this world. There are other simple inexpensive modelers also being used, such as, Alibre. Not to mention new comers, SpaceClaim.


Check out the image above of a Server Room. This is becoming more and more critical in the last few months. Large rooms with tremendous amount of heat being generated by rack after rack of computers. The rules of thumb just aren't cutting it. We recently visited a company where they were popping floor tiles up so that they can control where the air would go. Pretty crazy.

There is a huge push to make everything "greener". So, I suspect that HVAC guys will be out there searching for a solution. There are tools out there that are primed and ready to address the issues. Go check them out... http://www.cfdesign.com/


Friday, November 23, 2007

The "Manufactured" vs. "Simulation" CAD Assembly

There is a clear distinction between the "manufactured" CAD assembly and the "simulation" CAD assembly. When using simulation "Upfront" in the design process, we prefer to have a conceptual model that does not include all of the nuts, bolts, interferences etc. We would rather only include those parts and features that are critical to the type of analysis being conducted. So, for a flow analysis, we only really care about the "flow path", everything else is just additional info that may take time to address with little to no value to the analysis. If we include the thermal effects, than we need only the critical components and can ignore tiny components (bosses, fillets, chamfers etc) that will only make the model larger but can be simplified or ignored. Often times, this can reduce the solution time by up to 1000%. So in real numbers, this can result in a model taking less than an hour vs. overnight. To go one step further, this can result in doing 10 Upfront CFD simulations in a day or two rather than a week or two. Pretty signicant.

Sometimes, we are lucky enough to start with a clean sheet and build a conceptual model from scratch. But more often than not, we have a legacy model that needs to be redesigned or the next generation design will leverage legacy parts. So, what are the things we are looking to simplify or eliminate so that our models will run as fast as possible? The easiest question to ask yourself "if I get rid of it, will it alter my results by more than 5%"? If you don't know, than you should probably keep it.

So, here is a quick checklist if you are doing an Upfront CFD analysis...

Always, always start simple and work to the more complex.

Get rid of all fillets, chamfers and small edges. Keep only those that are in the "flow path" and will alter the flow behavior substantially.

Get rid of interferences and tiny gaps. Best to ensure that parts are coincident and/or concentric.

Leverage "alternative" assemblies (simplifid reps in Pro/e, configurations in SW, Levels of detail in Inventor etc).

Don't be afraid to re-assemble a simulation-only assembly. It is sometimes quicker to assemble a model from scratch rather than simplifying the original.

These are obviously guidelines. You have to weigh the time needed to simplify the model versus that of the time we are saving. I have found that time spent on simplifying almost always pays off in the end. Being able to identify the"ideal" model may take some experience. But the vendor you choose should be able to give you quick guidelines that should be able to get you there. Make sure that they understand your design process.

Much more to come on this in the coming weeks. I'd love to spark a discussion on which product has the best tools for simulation folks. I definitely have my own opinions. Also sparks the question, how about a tool for the simulation guys that do not drive CAD? Well, appears as though SpaceClaim boys are here to save the day. http://www.spaceclaim.com/

Sunday, November 18, 2007

Communicating and Sharing our 3D Designs

I remember back in the late 90s, there was a huge push to transition companies from 2D to 3D. Believe it or not, there is still quite a bit of buzz about it. Probably has to do with the fact that there are 4 million+ 2D AutoCAD seats out there. So, companies like Inventor, SolidWorks and Solid Edge are slugging it out to convert companies to 3D. Perhaps I am spoiled, but I can't imagine designing anyting mechanical in 2D. 3D, seems to becoming the accepted standard. I think the creation of the "mid-range" market (SW, Inventor & SE) really exposed companies to the idea of 3D. Prior to 1995, a seat of Pro/e was $20k and required a machine that was equally priced to drive. SW exploded on the market and totally changed the playing field. One "wow" factor that SW used in the late 90s (and widely used today) is "edrawings". It is a standalone viewer that provides a means to share, mark up and view models in 3D. One of the cool things they did was allow users to package up the viewer and model and send it to someone. This bypassed the need to have to download the viewer on the other end. Very cool for the time, however, email servers tend to strip off the "*.exe" these days. As you can imagine, every other CAD vendor jumped on the bandwagon and provided their own viewer. I recently tested out Autodesk's version called, Design Review. I really like their interface. Check out some of the cool navigation tools in the model window.
Things have come even further. We now want the ability to share our simulation results with the world. Check out the video below. It is a 3D viewer for CFD results. It can act as a standalone application or can be embedded inside a power point presentation. So, imagine presenting results to a team of engineers, or even better, non-engineers and have the ability to pan, zoom, rotate and animate your results. Cool stuff...

Thursday, November 15, 2007

CFD is easier than other FEA Simulations!?!

Sounds as though I am going against the grain here a bit? There are many engineering management teams that feel CFD is beyond their reach. The perception is that it is complicated, difficult to use and require a PhD to drive it. However, Structrual FEA has become almost as common as 3D CAD in many organizations. Often done "upfront" in the design process. So are structural problems so much easier to setup and solve?

In fact, there are a fair amount of decisions to be made when setting up a structural simulation of a typical mechanical assembly. Often, constraining the model can be a challenge. Also, how the parts interact can pose some questions and requires some experience to choose the correct settings. Is it bonded, sliding, frictional contact etc? What exactly is a "penalty method"?Does the model undergo large deflection, causing the analysis to be non-linear? How about material properties - elastic or plastic? FEA vendors, such as ANSYS, MSC and COSMOS have improved their interfaces substantially over the years. Some allow you to read the CAD model directly into the FEA interface. Others leverage the CAD interface and are "CAD-embedded".

So why is CFD so scary? Well, for one the equations are intrinsically non-linear. Meshing has posed some challenges, as CFD simulations tend to be more mesh sensitive than structural problems. But, the need is there. There are 100s, 1000s of companies that manufacture valves, pumps, manifolds, flow meters, fans, nozzles, medical devices, ducts, hoses etc that could substantially benefit from a flow simulation tool. Not to mention thermal effects. Think of how many mechanical designers are working in the electronics industry that would love to be able to ensure their products will not overheat once they hit the market.

If we think about the decisions that need to be made to set up a flow simulation, they are actually quite a bit less than their structural counterparts. Typically, a flow rate or pressure at the inlet and a pressure at the outlet. Material properties are just density and viscosity. Still cautious? You should be.


There are many CFD vendors that have been around for along time and have been very successful. The merger of CFX and Fluent under the ANSYS umbrella makes them the super power of CFD. Right? How about the guys at Star-CD? They speak the language of fluid guys, analysts. They are very good at what they do and serve their market very well. It just doesn't seem like they are ready to enter the design community. Can't say that I blame them. It is a complete cultural shift for them. Sure, they have "entry-level" tools but there is a huge difference between entry-level and an upfront design tool.

Entry level is exactly that. It implies a first step, the need for more at some point. Perhaps OK for some companies. But it can have a mixed message. It can be a risk for a company to make the entry level product part of their design process, but then hit the ceiling very early and then have to move on to "the real deal". They are now required to learn yet another interface, a new process, make bigger more complicated decisions. This step typically requires a significant additional investment in implementation or worse, the need to hire a specialist. Regardless of which path is chosen, the end result is the same. Less productivity, more time wasted and a lack of ROI in the end.

Instead, companies should make the assessment early on as to what their needs are for say the next three years. What kind of problems will you need to solve? What resources do you have or could you get to solve those problems? But more importantly, partner with a vendor that is focused on solving your types of problems, your way. If you are an Inventor house and design and manufacture valves, then the folks you are working with should surely be versed in both of these. They should speak your language, not require you to speak theirs.
There are vendors out there that are focused on this market- the Upfront CFD market. Certainly, don't want this to come across as a shameless plug. I am clearly a believer. But then again, I have seen all sides of the argument. Proof is in the pudding. Take a look for yourself. Jump on Google and see what all the hype is really about. I think you'll be pleasantly surprised. More to come..

Sunday, November 11, 2007

CFD is Cool..it's even on YouTube

Amazing to see how far along CAE software has come. It is becoming more and more mainstream. So cool to see it being used in so many different applications. Programs are becoming easier and easier to use, it simply allows more and more people to use them. It was only a year or two ago that SolidWorks had the boys from Orange Country Choppers guest speakers at SW World.

The fact that people are posting clips on YouTube simply proves that CAE and specifically CFD are becoming mainstream.

There are literally countless videos of CFD, CAD and FEA examples posted on YouTube and even MySpace. It's really awesome to see our little world becoming mainstream. See for yourself, go to http://www.youtube.com. Search for "SolidWorks", "Autodesk Inventor" or any of the other mainstream packages out there. Funny if you search for "CFD", you will get a bunch of Chicago Fire Department videos. But dig deeper, you'll find them - try "cfd flow".

It makes me wonder what the future brings? Meaning, exactly how mainstream will it become? We are already seeing the number of vendors reducing substantially due to acquisitions and mergers. Dassault Systemes has SolidWorks, Catia and ABAQUS (now re-branded Simulia). Siemens has Solid Edge, UGNx and its own NASTRAN version. Not to mention, ANSYS, who just seems to just be buying and buying. I posted earlier on PTC acquiring CoCreate. And last but certainly not least, Autodesk has finally entered the simulation market by purchasing Plassotech earlier this year.

What's next? Who else will get into the mix? Adobe has entered quietly with their version of a 3D pdf. It is only a matter of time before this is being used all the time. It simply will expose 3D models that we engineers build everyday to the rest of the world.

I wonder if Microsoft, Yahoo, Google or even Apple will get into the game. Can you imagine Google being a CFD vendor? Or better yet, Steve Jobs demonstrating at a user conference? I am probably getting carried away. But you never know...

Saturday, November 10, 2007

How to stay in touch when on the road...internationally

Many of us are required (or choose, depends on your perspective) to be on the road for work and be away from those that are close to us. There are many ways to stay in touch..email, mobile phones, ims, webcam etc..

Even a few years ago this was a challenge. Remember the days before high speed internet? Local mobile plans were a real treat and calling cards still cost too much. Things have definitely changed quite a bit. Nearly everyone in the US has a nationwide mobile phone plan. Many have PDA phones that allow emails and texting. So, as long as you are traveling in the US, you can stay connected fairly easily. Maybe even connected too much, by some standards?

But once we travel outside of the US, things can get complicated. Well, let's face it, things get expensive. Making international calls are getting more reasonable, but roaming is outrageously expensive. Even if you pay the "upgrade" fee to "get the best" price. It costs ~0.99/min in Europe. So even a quick call home can be a few bucks, but usually much more.

One option is to get a prepaid SIM card for the perspective country and make the long distance call home. Still expensive and a drag to have to go through the hassle. I just returned from a trip to England and have found new ways to "call home".

I recently began using Yahoo Messenger to call home. The exact service is referred to as Yahoo Voice.
So, assuming that I can get descent quality high speed internet access, it has worked out very well. If I call pc to pc, it is free. Yeah, free. If I call pc to phone it is $0.01/min. That is half of the cost of its primary competitor Skype. Another really cool feature is "phone in" service. Allows me to choose a local number that anyone can call that will then ring me at my computer. If I am not there, they can leave a message. I can also forward my US office phone to that number so that I can retrieve voice mails while on the road. Otherwise, even checking voice mail would be a long distance call.

As long as the internet connection is descent, the sound quality is not bad. I did have slower connection in one hotel and the delay was quite annoying. I find that it is more of a hassle to ensure that my headset is working properly. Seems to have a mind of its own. Mutes the mic, uses the computer speakers instead of the headset. Simple reboot seems to clear up the issues. I am using a Plantronics DSP-400 headset.

Another perk when traveling is using a webcam. Currently
I am using a Logitech Quickcam Deluxe for Notebooks. I love the size and the image quality is descent. But I have to say, the stability of the camera isn't the best. It tends to crash my computer (BSOD) quite often. So, I have to be very careful when I use it not to have too much else running on my machine.

The key to both the headset and camera that I am using is that they are both fairly portable. The camera is literally the size of a box of matches. The headset folds neatly, but does have a clunky "voice enhancer" thing of some sort. Looks like a battery pack.

I feel like gypsy because my bag has so many things in it. But staying connected is important to me, so its worth it. These are the gadgets I use for communicating. I am also way into music, I'll save that for another time.

Monday, November 05, 2007

A Day in the Life of the Virtual Engineer?

Probably the most fundamental part of being a virtual engineer is that I work remotely for a software company. So, I work from a home office and work in a virtual office environment. This lifestyle is certainly not for everyone, but I can't imagine it any other way. People constantly ask what exactly do I do all day since I don't go into an office.

My primary responsibilities include pre and post sales technical support and training. Something we refer to as Field Services. So, I work closely with a team of engineers scattered all over the world. Most are in a similar situation and are fortunate enough to work from home. We work with our customers to ensure that they are successful using our tool to help them design and engineer better products. The software we develop is a fluid flow and heat transfer (CFD) simulation package. Conveniently referred to as virtual prototyping software.

Being in a virtual working environment has many advantages but also has its challenges. You have to be pretty disciplined and communication is critical. I am somewhat obsessed with communicating efficiently. It is easy to get caught up in the latest gadget that hits the market. But inevitably, it is a crucial part of our lives.

So, what are some of the tools we use to stay connected?

Obviously phone and email play a big part. We recently implemented MS Office Communicator (OC). An instant messaging program from MS. Integrates with Outlook etc. It has alot of really cool functionality such as file sharing, web cam and voip capability. What I like about it is that it is easy to have everyone log into the same server etc. We can then quickly see who is online and who is available etc. http://office.microsoft.com/en-us/communicator/FX101729051033.aspx

Being in the software business, it is really handy to be able to have web meetings that allow us to share and view other's desktops. We have been using WebEx for quite a few years. Works fairly well. Many others out there like it, but we will probably stick with Webex for the time being.

When not in the office, I have a Treo750. Until the iphone hit the world, I thought the treo was the coolest phone out there. Easy to use, runs Windows Mobile. So grabbing calls, emails and texts are all very easy. I am in the process of seeing how I can incorporate
MS OC into my mobile device. This way I can be in instant contact with other members of the team.

Another service while on the road that has been invaluable is iPass (http://www.net-roamer.com). Essentially, it is a WiFi service that allows me to connect to the internet in airports, some hotels and coffee shops (Starbucks etc). Recently I found it very useful when traveling in England. Saved me having to pay ~$30 for a 24hr pass.

These are just some of the basics that we use. I would love to hear what others are using? I have recently gotten into using an im service to make phone calls. More on this very soon...

Sunday, November 04, 2007

Ease of Use: Unique vs. Innovative

Every vendor claims that their product is easy to use. But I think there is a misconception on what easy to use really implies. Easy to use to one user, may be in fact counter-intuitive to another. There is a major difference between being unique and innovative when it comes to ease to use. Take, for example, CATIA and SolidWorks. Both owned by the same company. Granted developed from the ground up separately and arguably targeted to different markets.

But I don't believe there are two codes on the market that do much of the same things but are orders of magnitude different from one another in what I consider ease of use. Does easier to use mean less powerful? I'll save that for a different post.

But back to ease of use. I have been driving SolidWorks since SW95. So, I consider myself pretty capable. I have been driving CATIA for half as long. However, I just attended a CATIA course this past summer. I love intro training classes. I really don't believe there is a better way to become a power user than learning the "method behind the madness".

So there I was in a room full of guys from my company all power users of at least 2-3 separate CAD systems and many of us walked in with a biased dislike for CATIA. Why is that? Well, because it is drastically different than most of the other CAD systems. Clearly, CATIA has some more functionality than many of the others, but why is it so different?

I am not that picky of a user. I can usually figure stuff out. Roll with it, as they say. RMB for this one, rather than LMB. Ok, all good, I'll figure it out. But CATIA is drastically different in all aspects. Extrusion/protrusion is a PAD!? A cutout is a POCKET!? Ever try and rotate, pretty funky.

Sounds like I am just bashing poor ole CATIA. Not really. About half way through the first day of the training, I was actually digging it. Check out a faucet in CATIA R17 above. Keep in mind though, I was psyched that I was able to create a LOFT, SWEEP, booleans etc. Very basic things. I was beginning to understand what they expected me as the user to do. Seems counter-intuitive to me. Remember, I am looking at CAD from a simulation perspective. I don't really care about the detailing capability. But, I need to open a production level model and have a handle of the basic modeling functionality. I appreciate uniqueness, but not at a cost of learning "their" methodology. Rather I want them to adopt to "mine and yours".

Now on the opposite end of the spectrum, we have SolidWorks. I gotta admit, I really like SW. I always have. In the beginning, I was drawn to them because they were the underdog. Up against big bully Pro/e. But literally, SW changed the way people view CAD. But I will go one step further. I think they changed the way engineer's look at software in general. They have blazed the trail for FEA and CFD vendors to actually follow suit and concentrate on developing GUIs that can be driven by the masses. What I love about SW is that "they allow you to do what you want, how you want to do it". If that enters their marketing literature, I want my cut. Check out the same faucet in SW2008 below.

The look and feel of SW is pretty straight forward. They took a little fromn Pro, a little from UG etc and alot of their own special sauce all wrapped into one. So, if you like to have to fully define your sketch, ok. If you don't, ok. Are you a RMB kind of guy or do you prefer dialog boxes? When in a command there are no less than three ways to click "Ok". That is innovation in my book. It's not over crowding the interface but rather appealing to people from all walks of life. They definitely do things different than others, but when you see it, you get it right away.

Quite frankly, others are falling in line. Inventor has come leaps and bounds and is becoming a true competitor. UGNX5 is slick. I never thought I would say that. Others have some catching up to do, sorry Solid Edge. Pro/e, well, they are definitely unique.

I am fortunate to be working closer with european companies this year. So, perhaps, I will have a different take on CATIA as we move forward. Sitting in a Starbucks in London right now about to kick off a week visting companies in the UK. More soon..

Thursday, November 01, 2007

PTC buys CoCreate...why?

I just grinned ear to ear when I read this. Not sure exactly why? Perhaps, because I can't for the life of me figure out how PTC will incorporate yet another technology that is quite different than Pro/engineer into their portfolio. But maybe that's the cool part, I am now intrigued and will be watching it closely.

I have used both CoCreate and Pro. Definitely, not a power user of either but can drive both fairly well. They couldn't be any more different. That, again, that is what intrigues me. Also, how will ICEM Surf come into play? Are all three going to be merged into a new hybrid blend?? Lots of buzz out there about hybrid modelers.

I'd love to be in the product management meetings. Maybe I am the only one? But what a challenge - both technically and commercially.


I wonder if PTC is feeling the heat from the new comer, SpaceClaim? SC has a similar non-feature based approach that CoCreate has been preaching all along. I have been driving SC for the last few months. I think the interface is awesome (check the image above). Totally different approach than the traditional CAD tools on the market. Lots of grabbing and dragging. I use it primarily to create and modify models for analysis. So it works nicely for me. But then again, I am in the targeted market for SC. Check out the cool image below.

What is it like growing up in the CFD world?

I have worked in the Computer Aided Engineering (CAE) world for over 10 years. I have been fortunate enough to have worked with numerous products ranging from nearly all commercial CAD tools to ANSYS and other FEA tools. But the majority of my time has been devoted to the CFD world. Graduate work involved doing fluid flow measurements in the lab.

I then moved into writing small portions of CFD code to using some developed by others for specific applications. At the time, these codes seemed awesome. It was amazing what they could do at the time. Imagine spending a few weeks creating a grid by hand and being fascinated at seeing a few vectors on the screen.

But as we all know computer power and commercial CFD codes have come leaps and bounds since then. I love the fact that CAD vendors are being pushed to make their products easier and faster etc. Simulation software is not far behind.

There has always been a belief that if an analysis product is too easy to use, than it must not be any good? Pretty funny when you read it, isn't it? But its been a myth out there for along time.

I think we owe it to ourselves to push the vendors to create products that are not only cutting edge, but easy to use and make us more productive engineers.

PTC buying CoCreate? More on that in a bit....