# Electric Aircraft for Engineering Senior Design Project

### Help Support HomeBuiltAirplanes.com:

#### pictsidhe

##### Well-Known Member
That chart doesn't list motor efficiency. It does show how much worse the thrust per watt is as power is increased.
It shows RPM, torque and power consumption. From those, efficiency can be calculated. I paid no heed to the thrust, as I'm expecting the students to use different props.

#### BBerson

##### Light Plane Philosopher
HBA Supporter
It shows RPM, torque and power consumption. From those, efficiency can be calculated. I paid no heed to the thrust, as I'm expecting the students to use different props.
Looks like 78% efficiency at 100% power (if I calculated correctly converting Newton to foot pounds)
I don't know if I would trust those chart numbers, I don't think the voltage stays a constant 60 volts. So I don't know how they test electric motors for efficiency. Surprised they don't list the efficiency on the chart.

#### tgcastleman

##### Member
Thank you all for the responses and interest. I know this might be a little bit harder to read, but I'm going to respond by number.

#5) Our assignment was to design "something that moves"... I took that and went with electric aircraft.
#6) In short, research. To state the somewhat obvious, battery technology isn't really quite there yet to create commercially practical aircraft. So this will serve as a platform for research and data for when the battery technology is mature enough for aircraft.
#8) We're essentially doing that. I would rather not say which design yet, but it will be somewhat obvious when the project progresses.
#9) I apologize for my snippy retort. I am so used to receiving flak and non constructive negativity over this project that I suppose I may sometimes interpret sarcasm where this isn't any. Thank you for clarifying that. In short why electric and why not steam, I would say it is less complex and emissions free (not counting manufacturing the battery)... Mostly that first part. I've never made a steam system before, so I'm not going to kid myself in thinking that I could build a steam engine capable of powering an aircraft with my current skill level. If you're so interested in a steam aircraft, then I suggest you pursue one! One doesn't need an engineering education to design an aircraft. I would say you would need some books and basic math skills but it sounds like you're already on the right path. I'm sticking with electric. Calling it inside the box and another version of the wheel honestly made me laugh out loud. I know I'm not the only one working on this. I'm one of many and happy to be a part of it.
#10) Yeah we don't even have an aerospace department here at Lamar. I'm in mechanical engineering. So it is unlikely this project will be finished. I would like to build it, but that's wishful thinking right now.
#11) Yes it's a lot of work.
#12) Could you recommend a better motor?
#!4) LOL! And thank you!
#15) I would want to avoid a forward swept wing, and I don't think I'm going with a canard (although I haven't ruled that out either).
#17) Yes thank you.
#18) I wasn't sure what you were trying to say.
#19) No. I'm doing the work. Posting on the internet for opinions is hardly cheating a design project.
#20) The short answer is research. It will have a very limited range, but the idea is that this will serve as a test bed for future aircraft that will perform better and more practically. I put the Davis DA-11 in the proposal as one of the design influences. I think I'm going to shoot for 1000' takeoff length, but that may be increased to up to 1800 (I believe I have easy access to a 2000' runway). A lot of "I think"s there.... lol
#21 & #22) I haven't gotten that far in calculations yet and I have to be honest electrical power is not my personal strong point. Another team member is focusing on that.

I appreciate the responses and enjoy the discussion!

#### stanislavz

##### Well-Known Member
HBA Supporter
Absolutely yes for 4 x 10 kw, than one 40kw. More power into one brick shaped motor - and air cooling is not sufficient. And if building same 40kw motor as a thin pancake - it will be roughly 80 cm in diameter, with 25mm stator thick.. Thicker stator - more rpm / less cooling area = water cooling and way more expensive solutions.

#### Aerowerx

##### Well-Known Member
Isn't getting outside help on a project you are supposed to be doing yourself sort of like, for lack of a more delicate term, cheating?
No.

Actual help yes, but "market research" and "prior arts" are an essential part of any project like that. And there is nothing wrong with asking for opinions and advice so long as the students do the actual work themselves. Many times such senior class projects are nothing more than collecting information from various sources, organizing them, and proposing a course of action for further work.

If you do get outside assistance, then it should be acknowledged in the written report on the project.

Last edited:

#### Pops

##### Well-Known Member
HBA Supporter
Log Member
Thank you all for the responses and interest. I know this might be a little bit harder to read, but I'm going to respond by number.

#5) Our assignment was to design "something that moves"... I took that and went with electric aircraft.
#6) In short, research. To state the somewhat obvious, battery technology isn't really quite there yet to create commercially practical aircraft. So this will serve as a platform for research and data for when the battery technology is mature enough for aircraft.
#8) We're essentially doing that. I would rather not say which design yet, but it will be somewhat obvious when the project progresses.
#9) I apologize for my snippy retort. I am so used to receiving flak and non constructive negativity over this project that I suppose I may sometimes interpret sarcasm where this isn't any. Thank you for clarifying that. In short why electric and why not steam, I would say it is less complex and emissions free (not counting manufacturing the battery)... Mostly that first part. I've never made a steam system before, so I'm not going to kid myself in thinking that I could build a steam engine capable of powering an aircraft with my current skill level. If you're so interested in a steam aircraft, then I suggest you pursue one! One doesn't need an engineering education to design an aircraft. I would say you would need some books and basic math skills but it sounds like you're already on the right path. I'm sticking with electric. Calling it inside the box and another version of the wheel honestly made me laugh out loud. I know I'm not the only one working on this. I'm one of many and happy to be a part of it.
#10) Yeah we don't even have an aerospace department here at Lamar. I'm in mechanical engineering. So it is unlikely this project will be finished. I would like to build it, but that's wishful thinking right now.
#11) Yes it's a lot of work.
#12) Could you recommend a better motor?
#!4) LOL! And thank you!
#15) I would want to avoid a forward swept wing, and I don't think I'm going with a canard (although I haven't ruled that out either).
#17) Yes thank you.
#18) I wasn't sure what you were trying to say.
#19) No. I'm doing the work. Posting on the internet for opinions is hardly cheating a design project.
#20) The short answer is research. It will have a very limited range, but the idea is that this will serve as a test bed for future aircraft that will perform better and more practically. I put the Davis DA-11 in the proposal as one of the design influences. I think I'm going to shoot for 1000' takeoff length, but that may be increased to up to 1800 (I believe I have easy access to a 2000' runway). A lot of "I think"s there.... lol
#21 & #22) I haven't gotten that far in calculations yet and I have to be honest electrical power is not my personal strong point. Another team member is focusing on that.

I appreciate the responses and enjoy the discussion!

#9 --- So you had the freedom to go in a lot of different ways. Have to agree, electric is far less complex, but don't let a complex and unknown subject stop you from learning. Isn't that what this is all about.
When my youngest son was doing his Senior Design Project,( 1989), he designed and built a GPS type of Navigational system that used the earths magnetic field to replace the GPS transmitters in satellites . Designed and built the computer and all the electronics from scratch. ( I had the job of designing all the PC boards). Worked great except for the various iron ore deposits on the earth but that error could have been programed in.

Last edited:

#### pictsidhe

##### Well-Known Member
Looks like 78% efficiency at 100% power (if I calculated correctly converting Newton to foot pounds)
I don't know if I would trust those chart numbers, I don't think the voltage stays a constant 60 volts. So I don't know how they test electric motors for efficiency. Surprised they don't list the efficiency on the chart.
I got 70 something for full power. At part power, mid 80s. I converted rpm to rad/s to get shaft power in watts. They probably don't list it as it isn't particularly good.

#### RonL

##### Well-Known Member
HBA Supporter
Making steam using electricity, might be the cleanest and simplest thing you could do.

#### Pops

##### Well-Known Member
HBA Supporter
Log Member
Making steam using electricity, might be the cleanest and simplest thing you could do.
Electricity is not clean just a little cleaner. How are you going to make the electricity in the aircraft ? Aren't we back to batteries again ?

#### pictsidhe

##### Well-Known Member
About 20 years ago, I drove past a power station belching huge amounts of black smoke. I have never seen anything like it. That was in Nevada, where they don't care about air quality. Every single Watt went to California, who exports their pollution while claiming to be 'green'...

#### Hephaestus

##### Well-Known Member
Are they seriously running old school coal power generation anywhere?

We've been decades on 'clean' coal up here. (The greenies don't differentiate) the big uproar a few years back, when the nutty communists decided to outlaw coal - funny some are less carbon intensive than the natural gas they're being replaced by, without the billion $conversion costs. #### Richard Schubert ##### Well-Known Member No. Actual help yes, but "market research" and "prior arts" are an essential part of any project like that. And there is nothing wrong with asking for opinions and advice so long as the students do the actual work themselves. Many times such senior class projects are nothing more than collecting information from various sources, organizing them, and proposing a course of action for further work. If you do get outside assistance, then it should be acknowledged in the written report on the project. Fair enough. Did you read this part? I would prefer not to post too many details here on the internet right now, but we are seeking experienced advice on general aircraft design and electric propulsion for aircraft. If you are interested in being involved, please send me a message on this website with a brief description of your applicable experience/education and interest in participation. . At any rate, I wish him good luck. The best engineering job in the world may very well be one that allows you to design cool stuff that will never actually see the test of actual practical use. #### Pops ##### Well-Known Member HBA Supporter Log Member A lot of my work in the 1970's was installing the air pollution equipment in the coal powered generation plants in the eastern U.S. #### pictsidhe ##### Well-Known Member Are they seriously running old school coal power generation anywhere? We've been decades on 'clean' coal up here. (The greenies don't differentiate) the big uproar a few years back, when the nutty communists decided to outlaw coal - funny some are less carbon intensive than the natural gas they're being replaced by, without the billion$ conversion costs.
I don't know if they still are. But they certainly were in Nevada in the 90s. Plants like that were all closed in Europe a very long time ago. 60s or 70s, I think. the fact that the Nevada one was powering a state that had also long since banned such plants was particularly poignant. it was right on the border...

#### Pops

##### Well-Known Member
HBA Supporter
Log Member
About 9 large coal fired power plants on the Ohio river and one on the Kanawha river. If they went off line, DC would probably be dark. WV major exporter of grid power to the NE. I worked building and maintained almost all of them.
The greenies in the NE must think the power magically appears out of the wall socket.
I have lived without electric, a lot of people don't have a clue what it would be like.

Last edited:

#### RonL

##### Well-Known Member
HBA Supporter
Electricity is not clean just a little cleaner. How are you going to make the electricity in the aircraft ? Aren't we back to batteries again ?
I base my thoughts on the facts that drag on a plane increases at a square factor, while the energy in a mass airflow increases by a cube factor (hence my comments about a tornado tube in the recent past).
Steam for a plane makes sense to me in one way because on many occasions I have watched planes land and on the approach, the wingtips generate vortexes that produce moisture condensation that trails 100's if not 1000's of gallons of water separated from the atmosphere.
With proper engineering wind-generated electricity and a collection of water from the sky might just negate a lot of battery capacity.

#### BJC

##### Well-Known Member
HBA Supporter
With proper engineering wind-generated electricity and a collection of water from the sky might just negate a lot of battery capacity.
I don’t follow you there. Can you explain what you mean?

Thanks,

BJC

#### pictsidhe

##### Well-Known Member
I base my thoughts on the facts that drag on a plane increases at a square factor, while the energy in a mass airflow increases by a cube factor (hence my comments about a tornado tube in the recent past).
Steam for a plane makes sense to me in one way because on many occasions I have watched planes land and on the approach, the wingtips generate vortexes that produce moisture condensation that trails 100's if not 1000's of gallons of water separated from the atmosphere.
With proper engineering wind-generated electricity and a collection of water from the sky might just negate a lot of battery capacity.
Ron. How strong are you? Can you lift your own body weight?
You can? Great!. Skip the plane, you don't need it! Get a couple of straps, put one under each foot, and lift. Flight! This will work exactly the same way as your complex wind generated electric driven aircaft. Except that you don't need the aircraft!

#### Pops

##### Well-Known Member
HBA Supporter
Log Member
I base my thoughts on the facts that drag on a plane increases at a square factor, while the energy in a mass airflow increases by a cube factor (hence my comments about a tornado tube in the recent past).
Steam for a plane makes sense to me in one way because on many occasions I have watched planes land and on the approach, the wingtips generate vortexes that produce moisture condensation that trails 100's if not 1000's of gallons of water separated from the atmosphere.
With proper engineering wind-generated electricity and a collection of water from the sky might just negate a lot of battery capacity.
Water is not the problem using a condenser to recycle the water with a little lost. The energy to make the steam is the problem with weight and volume. Lots of low rpm torque to swing a long prop.

Ultimate green aircraft, Put a sail on it like a sail boat How many mast ?

#### Dan Thomas

##### Well-Known Member
The greenies in the NE must think the power magically appears out of the wall socket.
I have lived without electric, a lot of people don't have a clue what it would be like.
A nationwide blackout for a couple of days would be highly educational for a lot of those people. A month or two without oil and natural gas would further enlighten them. The average journalist would learn a bunch of true stuff for a change.