[ Oran/NASAChatHost - 3 - 09:33:05 ]
Thank you for registering for the Turning Goals Into Reality/Aerospace Team Online chat with Brent Nowlin from NASA Lewis Research Center. Be sure you have read Brent's autobiography at http://quest.arc.nasa.gov/aero/team/nowlin.html prior to joining this chat. This chat is scheduled to occur on Wednesday, October 7 at 10:00 a.m. Pacific Time.

[ Susan/NASAChatHost - 4 - 09:45:55 ]
Good Morning Everyone, This is your old pal Susan Lee! Oran is stuck in another chat so it is my pleasure to host this chat with Brent Nowlin until Oran can join us! Remember to read all the questions to check if someone asks the questions you wanted to ask!! Also Read all of Brent's answers they might give you a really good idea for a question!!

[ Deb-Mrs.Regal/YpsilantiCOPE - 6 - 10:00:38 ]
Ypsilanti COPE is pleased to log on and have the pleasure of chatting with Brent Nowlin.

[ Susan/NASAChatHost - 7 - 10:03:10 ]
Good morning Ypsilanti! How was your summer?

[ DebandDane-Mrs.Regal/YpsilantiCOPE - 9 - 10:04:50 ]
Fine, thank you! And now we are excited to participate in more ADTO chats and especially with the Wright Flyer Online activities.

[ BrentNowlin/LeRC - 8 - 10:04:01 ]
Hello, I'm here to answer any questions. Brent

[ Susan/NASAChatHost - 10 - 10:05:04 ]
Welcome Brent! Do a lot of planes use turbine engines?

[ BrentNowlin/LeRC - 12 - 10:09:01 ]
Any jet plane uses a turbine engine as its means of propulsion. If a plane has a propeller, it probably has what is known as a reciprocating engine, which is somewhat similar to the engine used in automobiles (a lot larger, with many modifications, of course!). There is now a hybrid engine called a turboprop, which combines the turbine engine with a propellor to try a use the higher power of the turbine engine, along with the good efficiency of a propellor.

[ Dane-Mrs.Regal/YpsilantiCOPE - 11 - 10:05:42 ]
Could you please describe a typical workday in your present job?

[ BrentNowlin/LeRC - 14 - 10:13:11 ]
A typical workday is hard to define. Most of my days are pretty different from each other! Usually I check my e-mail and phone messages first thing in the morning. I then take care of anything that needs to be done in the turbine testing facility. Work in the turbine facility may include designing new systems, checking out systems, or simply operating the systems. The facility is pretty complex and has a large number os invidual systems, each system having a large number of individual pieces/parts. I then check e-mail / voice mail again around lunch time, then I head back to the facility for more of the same. Meetings that may be sheduled are also mixed in there as well.

[ Dane-Mrs.Regal/YpsilantiCOPE - 13 - 10:10:07 ]
What is the largest turbine engine you've ever tested at your facility?

[ BrentNowlin/LeRC - 18 - 10:16:50 ]
Dane, We test just the turbine portion of a gas turbine engine. The current turbine has 2 stages, which means that it has 2 individual parts that rotate. The turbine is about 24 inches across, from blade-tip to blade-tip. It's designed to spin at around 8000 rpm (revolutions per minute), and it generates 2000 horsepower. The turbine facility itself is designed to be able to test turbines that spin up to 17,000 rpm and generate up to 3000 horsepower. That's a lot of horses!

[ Susan/NASAChatHost - 15 - 10:15:05 ]
Do you have any help running the facility Brent?

[ BrentNowlin/LeRC - 20 - 10:26:08 ]
Susan, Yes, I have lots of help. There's another electrical engineer to assist me, and we are in dire need of a mechanical engineer (our mechanical engineer just transferred). Also, there are 2 mechanics, and an electronics technician that help out. There are also a whole bunch of other people that are available if needed (electricians, computer programmers, etc). Even though most of the systems are automatic, a lot of people need to be present to run the facility. Deb, Some of the modifications include changing the blading of teh turbines. As you may or may not know, you can think of a turbine as a kind of glorified windmill - it's a device that converts the energy of moving air (or a liquid) into shaft power. Usualy, the best way to improve efficiency is to improve blading. Researchers also are experimenting with using higher temperatures of the air going into the turbine. That helps boost power and efficiency, but it can also damage the turbine (melt the blades). That would be bad! So, a lot of time and research is being spent on ways to oversome the drawbacks of all these issues. To answer your second question, our tests are not geared specifically to increase the safety. Usually we are only interested in making sure that no unsafe condition does happen in our facility. People that are interested in increasing the safety have different facilities, and are doing a lot of work in that area. But it's an area that has things going on that we are just now beginning to understand and determine. It's a developing science.

[ Susan/NASAChatHost - 19 - 10:23:52 ]
I would like to once again invite you to let us know at the end of the chat what you think of today's chat at http://quest.arc.nasa.gov/qchats/qchat-surveys.

[ BrentNowlin/LeRC - 24 - 10:31:09 ]
RE: [Dane-Mrs.Regal/YpsilantiCOPE] What is the size of the turbine used in an engine for a 747?
Dane, I don't know exactly what the size is for a 747 turbine. I can tell you that, depending on the manufacturer of the engine, the size for a one turbine section of a 777 engine is about 30 inches across, and the other turbine section is about 60 inches across. I read that the inlet to that engine is 120 inches across (that's 10 feet!). I mentioned two sections because most large turbine engines have 2 separate turbine sections, and high pressure turbine and a low pressure turbine.

[ BrentNowlin/LeRC - 26 - 10:33:56 ]
RE: [Dane-Mrs.Regal/YpsilantiCOPE] What different kinds of fuels are used to power the turbines?
Dane, Teh fuel used to power turbine engines is Jet-A, although there are a lot of other fuels being investigated. In our turbine facility, we use natural gas to heat the air up before it enters the turbine. In a real engine, the air entering the turbine section is very hot, so we heat the air to simulate the air that the turbine would see in an actual engine.

[ BrentNowlin/LeRC - 28 - 10:40:56 ]
RE: [Deb-Mrs.Regal/YpsilantiCOPE] When you described the people necessary to operate the facility, you mentioned computer programmers and earlier referred to your use of e-mail. What roles do computers play in a testing facility such as yours?
Deb, You can't get away from computers anymore, even if you wanted to. Most of the devices used in our facility are either computerized or are used in computerized system. The data system, which measures and records the data from the facility, has 1100 pieces of information that come from the facility. Those pieces of information are things like temperatures, pressures, flow rates, and other parameters of interest. Also, the facility is controlled by something called a programmable logic controller. This is a device that controls the facility systems, like how much air is flowing through teh turbine, how much natural gas is being used (which determines the temperature of teh air entering the turbine), the speed of the turbine, and a lot of safety items. Also, we use computers with touchscreens as interafces for the facility operators. Those touchscreens have programs that the people use to open valves, turn pumps on, change the temperature, and things like that. All of these systems are computerized, as well a several that I haven't mentioned.

[ BrentNowlin/LeRC - 30 - 10:44:32 ]
RE: [Dane-Mrs.Regal/YpsilantiCOPE] How has your work changed since you began your career?
Dane, Yes, my job has changed quite a bit. The basics haven't changed, but the way we do things has. When I started 11 years ago, we still had turbine testing facilities to run. But, most of the systems were either manaully operated (run by people), or the controls were vaslty different. Now, most of the systems are automated, and have changed quite a bit. The mechanical aspects haven't changed as much, but some have changed. Most of the newer technology comes in the electrical/computer area, which is probably easy to see why.

[ BrentNowlin/LeRC - 31 - 10:48:22 ]
RE: [Dane-Mrs.Regal/YpsilantiCOPE] What kind of communication do you have with people who design the other parts of the turbine engines?
Dane, I also work in a compressor testing facility. The compressor section of a gas turbine engine does kinda the opposite of the turbine section - the compressor converts the energy of shaft power into the energy of moving air. It's very interesting to see the interaction of teh turbine and compressor sections. Changing the design of one may dramatically affect the performance of the other. I work somewhat closely with the people who design both the compressor section and the turbine section.

[ DaneandDeb-Mrs.Regal/YpsilantiCOPE - 34 - 10:56:24 ]
We need to log off soon. Thank you so much for your time and for your interesting and informative answers!! The best to you in your work.

[ Susan/NASAChatHost - 35 - 10:57:08 ]
Where does the time go? We're down to the last five minutes! Ypsilanti thank you for your interesting questions, I learned a lot from reading Brent's great answers! If you have time please let us know at the end of the chat what you think of today's chat at http://quest.arc.nasa.gov/qchats/qchat-surveys.

[ BrentNowlin/LeRC - 36 - 11:01:53 ]
RE: [Deb-Mrs.Regal/YpsilantiCOPE] What you wrote in your autobiography about the importance of integrity and ethics in your career is inspiring. Can you give us some specific examples of how the characteristics of diligence, honesty, and trustworthiness matter even in the world of "hard science?"
Deb, I guess I don't exactly know what you mean by "hard science". I'll interpret it to mean the world of applied science, that is, when people put scienfic principals to work in everyday life. That's what engineering is - applying scientific principals to solve a problem (as least, that's my definition!). When it comes to diligence, an example I have there is a system that a couple of us designed and built last year. It was a pretty complex system. We had an old system that worked, but not very well. So, we designed and built a new system. The system used parts made by several manufacturers. Some of the parts didn't work the way the manufacturers said they did (these are called "bugs"). We could have either abandoned the idea, and used the old system, or we could have stuck to the plan, found out ways around the bugs, and make it work. We chose to make it work. We were successful, and the system is now fully developed for what it was designed to do. The really great thing about that diligence is that the system can be easily changed to do a whole lot of wother things, as well. Honesty and trustworthiness are equally important. As a member of a team, I have to trust my fellow team members. I have to not only trust them to do their jobs, but also to help me out when I need them. I also have to be honest with them - if I can't do something, I have to tell them and we then find a different way. I find that honest is pretty common in the engineering profession, more so than with some of the other professions. In my job, though, we have to be honest with each other (and ourselves!) because there is a lot of expensive, powerful machinery involved in the day-to-day operation.

[ BrentNowlin/LeRC - 37 - 11:04:12 ]
RE: [Dane-Mrs.Regal/YpsilantiCOPE] What are your future career plans?
Dane, My future career plans currently consist of staying here at Lewis and investigating new things. I really enjoy building stuff - that's really what I love to do. Fortunately, at Lewis, I have that opportunity to do just that.

[ Susan/NASAChatHost - 38 - 11:05:47 ]
Brent, Thank you so much for this opportunity to learn about turbine engine engineering at Lewis Research Center. Your answers are terrific!

[ BrentNowlin/LeRC - 40 - 11:09:50 ]
RE: [DaneandDeb-Mrs.Regal/YpsilantiCOPE] Thank you!!!
It was my pleasure. I wish you the best in your future educational endeavours and hope that I have been helpful in answering your questions. Maybe our paths will cross again in the future. Have a great year!