By: Kurt Nichol
This month APEX Turbine celebrates our seventeenth year in business! Over the years not only has our business grown, but more importantly, our understanding of our market and our customers’ needs has grown. It’s been quite an adventure. As with most anniversaries, it’s a good time to look back at how we came to be.
Prior to forming the company, I was working at the Arnold Engineering Development Center (AEDC) in the technology department where a team of us, civilians, contractors, and Air Force personnel, worked to streamline the structural test and evaluation process. We worked on a variety of things including test planning, test support, and data acquisition and data analysis technologies. As part of our work, it was a fairly common practice to work with universities as subcontractors. One of our subcontractors at the time was Vanderbilt University, and one of our primary consultants there was Dr. Csaba Biegl.
A key component of improving structural test was the development of the Computer Assisted Dynamic Data Monitoring and Analysis System, or CADDMAS for short. This project transpired in the late 1980’s and early 1990’s and culminated in a real-time test capability that offered the ability to not only acquire dynamic data, but also the ability to view real-time Campbell diagrams. Because CADDMAS performed all FFT signal processing online, we were able to store and record processed data in so-called “dat” files which were used for quickly reviewing the data offline. CADDMAS was truly revolutionary. You can read about the development in
Of course, data acquisition and online monitoring was only one tool in our toolbox to improve turbine engine structural test efficiency. At about the same time, we also tackled the problem of streamlining dynamic data analysis and signal processing. The signal processing part of this wasn’t too difficult to overcome since CADDMAS was already storing processed dat files. The real challenge was to get through all the data in a timely fashion. To understand why this was a problem, you must first understand how much data could be generated.
A typical aeromechanical test program at AEDC would involve perhaps 48 dynamic strain gage channels scattered over a variety parts in an engine. Each strain gage would record vibrations for on the order of 20 modes of vibration over a typical accel/decel of an engine. But, because testing at AEDC involves testing at simulated altitude conditions, it would not be unusual to do these engine transients at 20 or more flight conditions with variations on the way the engine was controlled, or with various inlet distortion patterns. This could produce maybe 50 or more individual test conditions. So, in order to understand what all the measurements meant, we had to analyze resonant responses for 50 conditions x 20 modes x 48 strain gages or 48,000 responses! Each response had to be compared against some success criteria or limit. Responses that exceeded limits had to be trended against various test parameters to understand what to do next. Whew!
To make this much faster and easier, we created a computer program to quickly scan through the dat files looking for maximum responses for each mode of vibration. These responses were then compared against pretest-defined limits and stored in a summary file within the program. This tool came to be known as DatWizard. The summary file produced by DatWizard could be filtered, and could also produce X-Y plots for evaluating responses against a variety of engine parameters which enabled us to make maximum use of the data. This was our first foray into the world of “Big Data”.
DatWizard-Campbell Plot
We developed a few more products under US Air Force funding that did even more detailed kinds of analysis, such as BladeOPS and SDRAC. Check these out by looking up these papers:
“Minimizing Vibratory Strain Measurement Error”, ASME 98-GT-257, Nichol et al, 1998
So, what does all this have to do with APEX Turbine? Many of these capabilities were being used regularly by the test customers at AEDC. It didn’t take long for these customers to begin asking whether similar capabilities were available commercially, or whether they could access these tools commercially. And, technology transfer out of the government to the private sector can be challenging.
I’m a big believer in living life with no regrets and I don’t want to ever get to the place where I wonder “what might have been” so in late 1999 I began to consider starting a company founded around the technologies I had been a part of for so long. After many conversations in a lot of barbeque places in central Tennessee, Csaba and I decided to launch Engineering Design & Analysis Solutions, Inc., or EDAS for short. As part of the new start we worked with our friends at AEDC on a Cooperative Research and Development Agreement, or CRDA to acquire rights to develop and market AEDC-developed technologies. This allowed us to carry on the work of developing the products while marketing them and it allowed AEDC to benefit from improvements we made.
CADDMAS eventually evolved into our DS product with commercial off the shelf (COTS) hardware. This is widely used at AEDC (albeit they still call it CADDMAS). DatWizard evolved into our DX product after several iterations through DataDetective and WorkFlow. BladeOPS and GageMap were combined into GageMap.
Seventeen years and millions of dollars later, our products benefit our many customers around the world. Being a business owner has been challenging, but looking back I would make the same decision. It’s one of the most challenging and interesting things I’ve ever done. The only bad part of it is that I can’t complain about the management!
What does all this mean looking forward? APEX continues to refine our core products to make them even better and to make them applicable to complementary markets. Additionally, we are working on some entirely new products that we think will continue to benefit our existing customers and grow our reach into new markets. One of the best ways to learn more is to attend our annual APEX User Conference. We’ll be meeting in March 2018 in Nashville, Tennessee. It’s a great chance to receive training in aeromechanics, signal processing, or on how to use our products. Mostly, it’s an excellent opportunity for you to get to know us better. 2018 Apex Annual Conference
So let me conclude with a simple “Thank you” to all of our customers who trust us for products that they use every day to make their products better. It has been, and will continue to be our privilege to work with each of you.
