The math and speculating gets you a starting point for buildng the test wings... Then you evaluate the results of the test wings and... build a better wing.

BTW... yuo can do some homebrew "wind tunnel" testing... Refrigerator box on its side (cut a hole in the side of the box and ut a sheet of plexiglass in so you can see), and a box fan pulling air out. Not too good for high speed stuff... but it can give you a clue for the low speed project. If you can borrow a fire stations smoke blower... you can get a 40 mph breeze in the box eazilly.

Disagree with Ben.

Professor Emeritus Jim

???????? What? No supporting information?

And besides, I disagreed with Ben once and still have the virtual scars to show for it....

<As I set up a deck chair and open my bag of microwave popcorn to watch this match up..... >

Supporting information... instead of urban myth..
Yeah, that should be good.

I have arguments with myself all the time and I tend to win half and lose half. It is all very confusing.

Anyway, I did not leave any scars on Bruce. He should have seen the ones I got as I tried to work this out with a bunch of old time aero types. It was not a pretty sight, Ben - fresh out of college and knows everything. Old Timers - not fresh at all but have seen everything. They tended to be kind but not all the time as they lead me through my misconceptions.

It's like the apprentice said to the boss one day" Jim over there taught me all I know about this stuff". Jim over at the bench looks up at hearing his name and says" But I didn't teach you all that I know.....".

Ben, You commented that a professor might think negatively about the approach to problem solving the students are using. I am a professor, and I think what they are doing is just fine. In fact I would criticize them if they did not use all the resources they could find. As you say, some professors might, just not this one.

Jim

A very long trip.


Sorry... couldn't resist THAT setup.

man you guys did the research and all the leg work for these guys. That is a fairly easy problem. All they need to do is study what a wing does. Think outside of the box.

I think that full access to all written material both on the internet and libraries is fine - all of the theory and practical data is there but hopefully, not the answer to that particular question. I as a teacher would like to see what their little brains could come up with, not what some other old aero types might hint at. I think asking someone else for approaches to the solution, that is not in the problem solving group, is not finding out what they can do, but instead finds out how well they can get and use others' ideas.

I want to see them sweat bullets for that grade. No mercy.

I am a little jealous though, we just didn't have interesting stuff like that back in '65 and I did walk through the snow backwards several days at good old Purdue U. The only real thinking that went on were the contests we had in the Purdue Aeromodellers Club. We would make a set of rules of some sort (usually involving very little money) and after several weeks of secret work would have the meet.

One of them was a .049 CL contest to be done after a long break - 3 events one airplane. They were measured on speed, endurance with a given fuel supply and stunt. One guy came back to school with what looked like good airplane but he had trike landing gear about 6 inches long. He said that he hadn't bent the wire for wheels yet. We all chuckled at how funny the airplane on stilts looked.

The day of the contest he came to the event in the ROTC armory with little wheels on the end of the stilts and a 10 inch very light reworked wooden prop. He put in some shims in the TeeDee and fuel and fired up the engine. It went put.... put.... put.....etc. It barely got the plane off the ground and ran for ever. After the endurance part of the meet he cut the legs short (we had to ROG for each task) and proceeded to get great stunt and speed runs.

But in aero courses, not a chance.

I am replying to a reply to my reply (hahaha) earlier in the message board. Of course doing math is important, but without a lot of training in the area and without sophisticated equipment, you are just wasting your time trying to do complicated math formulas when you could be out experimenting. When I did my project, my team and I obviously did math and crunched numbers, but we only got a very small amount of data from it (data that we understood). But, when we started building, we learned and observed a lot of stuff that would have taken many months to learn from a book. Plus, math isnt fun, building and experimenting is the FUN part. My group and I had the best designed plane, the lightest plane, the highest weight of cargo to weight of plane ratio, the coolest looking plane, the slowest flying plane, and a third place finish. So, we must have done something right.

there is nothing like having theory and practice come together. I learned exactly how slow of mind I was while watching my son get a doctorate in EE. Developing new math to fit what he was working on, etc. My mind just doesn't warp around those things. I accept it. I proof read it for sentence structure (which was perfect) but after the first page I had no idea what the heck he was writing about. But watching him working I realize how it must feel when math is indeed fun.

However for most of what we need to do to work in aerodynamics on a practical level the math is easy and fits so well. It took me what seemed to be years to be able to watch an airplane motion and be able to put some math with it. I worked next to a brilliant aero who did the departure and spin work on the F-15. He would watch a film of the spin work and go through the process of determining what drove it so we could know what to do as a result, I was amazed at the depth of his understanding of the equations of motion and tried to pick up as much as I could. Unfortunately I am a slow learner. Drat.

What it does let you do is observe things and realize that tails do lift, etc. You will be more satisfied in your aero work in the future if you make the math fun too. It helps dispel all the old wives tales that seem to prevail amoung pilots and model airplane folks (no insult meant, don't beat me up because I said it, I am must trying to encourage the lad).

Ben, I worked with and for an autopilot genius who could observe the various parameters of an autopilot as they came out on a Brush recorder, and make instant fixes to the gains and adjustments to improve the performance.
Nasty person in person, but a true genius with numbers and why autopilots do what they do.