Who are Thermal Engineers? You might be one!

Brent Cullimore

I admit that I have chafed in the past at being called a thermal engineer. I have degrees in Mechanical Engineering and in Thermosciences. I consider myself more of a fluid/thermodynamics type: I love bubbles, and I think it is a sin if you stir cream into your coffee too fast and miss all the cool eddies. One of my hopes is to visit the grave of Boltzmann, where his legendary equation describing the entropy of systems like tossed coins is inscribed above his headstone, S = k * log(W).

What do any of those passions have to do with “thermal?”

Maybe you work in electronics cooling and don’t see any problem with the term “thermal engineering” (aka, thermal control, thermal management). Or perhaps you work with power generation systems, aircraft fuel systems, or liquid propulsion systems. What do those have to do with thermal?

I guess we could call ourselves “energy engineers” or even “thermal/fluid engineers.” I certainly like the sound of “power engineers!”

I’ve teased people that we are the Wet Side of Mechanical Engineering, to distinguish ourselves from the Dry Side: people who are way more gifted with gizmos and gears than I’ll ever be. Sigma doesn’t mean stress to us, it means either surface tension or the Stefan-Boltzmann constant. And no, we can’t change these values to make your latest wild idea work!

Some of the confusion is historical. As far as I can tell, the original thermal engineers came out of the shops of the early satellite makers, where vacuum testing was (and still is) very expensive. The value of thermal analysis (which unfortunately is itself a confusing term) was clear in that industry: any mistakes discovered after launch couldn’t be fixed.

But even that industry didn’t know what to do with us. Were we mechanical engineers? We sure aren’t like normal mechanical engineers. Were we designers? Except for the occasional heat pipe or radiator, we sometimes didn’t have any hardware associated with us. Were we systems engineers? We certainly tended to focus on the entire system in order to calculate energy flows and balances. Were we analysts? Well yes ... except for all the testing and the aforementioned heat pipes and radiators. Sometimes thermal engineers were placed in systems engineering, sometimes with materials folks. Most often thermal engineers were located where there was more overlap: with propulsion or environmental control (aka “climate control” in other industries).

Meanwhile, in the early electronics industry, some mechanical “packaging engineers” were tasked with making sure that chips and batteries didn’t overheat after they were designed. (Hey, I did say it was the early years, and if you were around then you know that electrical engineers were making all the decisions and we were left to deal with the consequences of those decisions.)

In the early automotive industry, the pressure to start from scratch and get the design right in terms of months instead of years did not exist. So people working fuel systems, AC systems, cabin climate control, engine oil systems, automatic transmissions, and so forth didn’t do a lot of analysis. Also, they all worked largely independently of each other. But when the need to catch up with the minivan craze (as one sad example) in 18 months became the norm in the 80s, CAD/CAE tools were quickly expanded and adopted. Gradually, engineers working diverse systems began to have more and more in common with each other.

I don’t know how you answer when asked “What kind of engineer are you?” But if you found this blog and bothered to read this far, I’m guessing something in the paragraphs above rang true for you.

These days, I’m OK being called a “thermal engineer.” If you aren’t OK with that label, at least maybe you can see why it is a convenient shorthand.

Choking and High-speed Flow

Tuesday December 17th, 2pm MST

When flow velocities get big, things gets interesting. Above Mach=0.1, the bulk fluid "sees" a wall that is warmer than the structural temperature due to deceleration within the boundary layer. Above Mach=0.3, kinetic energy changes cease to be negligible. And of course, nothing moves faster than Mach=1.0 for internal flow. When you also add in changes in flow area, or changes in phase ... well, let's just say that doesn't simplify anything.

This webinar will introduce you to the phenomena involved, with a focus on the FloCAD modeling parameters available and their associated correlations and assumptions.

Click here to register

Turbomachinery and Rotating Passages (Secondary Flows)

Thursday December 19th, 2pm MST

Are turbomachines a component in your system, and you'd like to treat them as a "black box"?

Or are they the focus of your work, and the cycle is just a boundary condition to you?

Either way, this webinar will have something to offer you. Each type of turbomachine will be covered: pumps and fans, positive and variable displacement compressors, and turbines (whether gas or hydraulic). Methods for modeling systems like turbochargers and turbopumps will be introduced. Tools for handling spinning flow passages and rotating cavities will be presented.

Click here to register

Starting in 2020, we will begin offering Introduction to Thermal Desktop and Introduction to RadCAD as either in-person training or online training, alternating between online and in-person every three months. The training uses lectures and demonstrations to introduce you to basic Thermal Desktop and RadCAD usage. Hands-on tutorials provide practice building models and interpreting results (tutorials are completed by students outside of the online class time).
 
The next training class will be an online format in January 2020:
  • Introduction to Thermal Desktop (and SINDA) - A three-part series on January 14, 16, and 21 from 9am to 12pm, Mountain time
  • Introduction to RadCAD - January 23 from 9am to 12pm, Mountain time
For up-to-date schedules, fees, and policies, visit our Product Training page. To register for the class above, complete our registration form and select "Online" for the Training Format.
 
If you are interested in product training for your company based on your schedule, please contact us to obtain a quote for training between 8-12 attendees. We can come to your facility or the lectures can be presented online. Descriptions of the available classes can be found in our course catalog.
 
To keep up with our training opportunities, take a look at our new Events and Training Calendar.