Posted on 09/14/2014 8:19:53 PM PDT by rey
He laughed at my ignorance of things aeronautical - until I took one of my RC models and fitted it out with a totally flat wing; a slab of balsa, it was, and flew it in front of him.
As a fellow R/C pilot, I need to remind you the Reynolds numbers that our models fly at compared to the Reynolds numbers of full scale aircraft.
Scale-wise, the air is much thicker to our models, and many such tricks as 3D hovering on the prop are easy at our scale, but has rarely been done full scale. (The Pogo being one full scale example.)
That being said, you could have just asked your friend if he's ever witnessed a full-scale aerobatic plane fly inverted. Or knife edge.
You didn’t mention the missing trim tab.
“I’m impressed getting that far along with a 10 year old girl. “
It is not as though she is well versed in all of this. She can find for the variable and for two variables if the problem is not overly difficult. More advanced work I hold her hand through it.
I think of it this way; our first admiral, Farragut, took command of a captured whaling vessel at the age of fourteen. He had to have a command of navigation (trig) and a command presence. John Adams’ son went with him to France, he was ten or twelve, he had a command of Greek and Latin and would soon learn French. At fourteen he went and served as secretary to the US Ambassador to Russia and was soon fluent in Russian.
I am woefully lacking at getting her up to where she could be, but she is better than most. Some people think I am mean (including her) as we are doing math at the fair and air show while others are running about being fools. I tell her that it is a metaphor for life and the sooner you come to terms with it the better.
“Too bad she has to miss out on the socialization benefits of public school - lowest common denominator education, crime, bullying, and such.”
Thanks. Your comment made me laugh. The socialization issue is one I am hit with all the time, especially from public school teachers. Socializing with whom, I ask? As you say bullying, as I had to cope with, lowest common denominator education as she had to (we are in an area with a lot of migrant labor, and while un PC, it lowers things drastically. The middle school she should be attending is a 55 out of 100 by the state’s admission.)? Certainly socialization is not more important than education; oddly, teachers reluctantly agree. Teachers are horribly shocked when I say that socialization will allow her to know more people in the unemployment line. They are further horrified that we support her playing golf and water polo for three reasons; one many girls’ scholarships go unanswered in these areas; two she meets a better class of people than out on the basketball court, softball and soccer field; and three, she wants to play them. Realistically, the people she will associate with in the future playing golf and polo are more likely to be the people that own businesses and hire. It sounds harsh but is analogous to hanging with your friends at the bar or associating with grad students in the library. The quality of life for one is vastly superior to the other.
Laminar flow, Reynolds numbers and boundary layer and how it applies to wing shape, materials, construction, speed through the air and the differing effects as they all interact.
The Doppler effect could be discussed and demonstrated as planes approach and pass, and neatly tied to discussion of weather and how it affects aircraft.
Sail a sunfish with her and experience the physics first hand!
“Keep in mind that lift is about 25% Bernoulli Effect and about 75% displacement depending on the wing cross section.”
THis was a pretty good explanation of what you were talking about.
http://www.allstar.fiu.edu/aero/airflylvl3.htm
Indeed, good points.
Nice post.
“...lift is easier to understand if one starts with Newton rather than Bernoulli.”
Bingo!!!!
Then try to explain the region of reverse command. Lots of fun there!
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