SpinOffs

In my last blog I wrote about visiting a local middle school to give a talk on ‘What is Turbomachinery, and How Does It Work?’   The quiz at the end of the talk was for the students to list all the turbomachinery in their home. I had a few examples in mind to get the list started but was impressed with how long of a list we were able to generate after the students thought about it for a while. Since then the list has grown to include 40 items.   I will present those 40 below, but first let me repeat the assignment and the ground rules to see if you can think of more:

1. List every piece of turbomachinery in your home.
2. Inside and outside (in your yard is OK).
3. Positive displacement equipment is OK to list.
4. Don’t include turbomachinery in your cars or any vehicle or wheeled yard equipment (that’s another list…)

On occasion I’m invited to a local middle school to give a talk to one of the science classes about ‘What Is Turbomachinery, and How Does It Work?’.   I teach in several of the turbomachinery design courses we give at Concepts NREC, and while I’m comfortable in those courses, presenting at this level was different. I originally found it a challenge to come up with a good presentation that would keep the students' attention, while still providing some science education as requested by the science teacher that invited me. Derivation of the Euler turbomachinery equation was probably out. The attention getters that seemed to work best to get the conversation going included bringing our turbocharger cut-away (definitely the biggest hit of anything I brought), along with other interesting impeller samples. From there getting into the purpose of various types of turbomachinery (compressor vs turbine vs pump) and a very high level discussion of energy transfer to/from a fluid, seemed to flow. Getting them thinking about some of the physical aspects of turbomachinery operation (Just how fast is 100,000 rpm?) also seemed to keep their attention.

If there’s one thing good about sitting in snarled traffic in Boston, it’s that you get to see some very original bumper stickers. The most recent bumper sticker I saw was probably the strangest one, no doubt created by some engineering professor who doesn’t see that the glass is half full, but that it has a safety factor of 2! Nevertheless, the bumper sticker stated the obvious when one thinks about it: ENTROPY HAPPENS! And then, to emphasize the point, the artist has the letters slowly “evaporating,” demonstrating graphically that entropy proceeds from order to chaos.

I recently got back from my favorite annual conference: ASME’s Turbo Expo. This year, someone thought it would be a good idea to hold it in Phoenix, Arizona…in the summertime.  While that’s not the choice I would have made, I did enjoy the conference very much and thought it was well worth attending. 

Turbomachinery equipment is generally segmented based on whether it extracts energy (e.g., turbines) or adds energy (e.g., pumps and compressors). The addition of energy is usually used to compress or move a fluid. When the fluid is a gas, the turbomachinery equipment is typically referred to as a fan, blower or compressor. This blog will explore the differences between these three devices and where they are used.  

Our CTO, Mark Anderson, takes a fundamental look at simple stall and its impact on turbochargers stability and range. This is the second video in this 2-part series. Be sure to watch Part 1 first!

Turbomachinery performance is almost always analyzed and tested with a fixed inflow condition. In other words, the assumption is that the inflow fluid temperature and pressure is defined and unchanging over the map of machine performance. Since varying conditions often exist in practice, the performance maps are sometimes normalized, as shown in the figure below. The pressure ratio of a compressor is plotted versus a corrected mass flow range and rotational speed. 

Our CTO, Mark Anderson, takes a fundamental look at simple stall and its impact on turbochargers stability and range. This is the first video in this 2-part series. 

In a previous blog, Fluid Phenomena Primer: Energy Versus Temperature, Specific Heat, I explained the behavior for gas phase fluids and how the temperature is affected at high energy levels.  In another blog, When Perfect is Good Enough - Perfect Gas Models, we looked at the simple perfect gas model.  In this blog, we’ll explore the next step up in the hierarchy of gas thermodynamic modeling: semi-perfect gas.

Valentine’s Day is February 14, and while some cynics refer to it as a “Hallmark holiday”, most people commemorate the day in some way. One of the biggest challenges is finding a card that perfectly captures the way you feel about someone, while also reflecting who you are.  Well, Concepts NREC has created some turbomachinery-themed Valentine’s Day cards for engineers. These fall into the Art end of our Art-to-Part Solution.