Thin airfoil theory [Aerodynamics #12] 

I'm glad you resonate with it and I felt a lot like you did during my first few aerodynamics courses!

Thanks! Hope you find it useful

I'm glad you found it! Good luck on the exam.

HAH. Sup Max. I am also here watching this through tears before tomorrow morning.

@@curtisgoldin oh yeah, it's cry time. I'm shooting for any grade higher than an F.

That's all pretty sweet. I got a job related to flight mechanics which I have never done before in my life since I studied control system engineering, so here I am now watching these videos :D They are so darn good tho I kinda regret. not studying aerospace before

Aw thanks! Glad you liked them

Thanks for the kind words and I'm glad you find them useful! Sometimes even just changing a learning format can help. Right now I am finishing the Fluid Mechanics series with a few more videos to go. After that, I will definitely consider something that connects these courses to real life engineering problems.

Thanks for the kind words!

Happy to do it!

Thanks!! I'm glad you find it useful!

Thank you!

Glad you liked it!

Thanks! Definitely, the writing can get small and fast, and I have horrible handwriting. If it helps, a PDF of the notes themselves are uploaded to my website: sites.udel.edu/vanburen/education/ those notes should be zoomable and may be a good reference for the older videos with small font

@@prof.vanburen oo thank you bro this is really nice of you , Thanks for replying.👏👏👏

@@prof.vanburen I dont find the handwriting so bad to read, in some lectures letters do get small (e.g. in previous lecture in integration it is hard to distinguish N/A and L/D). I think both writing and illustration is quite pleasant to watch and it is quite different from many other video lectures that just feel "dry". Also, even tho sometimes content is quite fast (you can always pause and ponder), there is a well structured and logical flow. Small improvements are always good, but overall - a very quality content. Reminds me on one of my favorite lecturers on control system theory: ru-vid.com

@@amirpasagic162 Thanks for the kind words! Brian Douglas at Control Systems Lectures is actually what inspired the format, their channel is awesome

Hi and sorry I am late to this! Where in the previous video are you referring to? The vortex panels can vary in strength distribution.

I hadn't seen that! Where are you referring to? I have only ever seen the derivation that considers the zeroth and first mode.

Yes, it must be 3 modes with A0, A1 and A2. A3 is zero. MIT website is a good reference on this

Hi John, that's a great idea! I definitely think adding a video about how to read the basic performance plots of an airfoil, like you would see in "Theory of Wing Sections" for example, and noting important features of the plots would be really helpful. I will add that to the list of upcoming videos!

@@prof.vanburen Thank you much appreciated for your support

Thanks for the keen eyes Amir!! I think you're right, there's a bit of a signage mix-up here. In this case, I think it would be a PLUS theta and the dx is technically negative so it would be tan^-1(-dy/dx). Ultimately, the next line has the correct signs. For your second part of the comment, it depends on your tolerance for small angle approximations, but atan(x) = x within 1% for angles up to 10 degrees. I think the line of equation (1) already has the small angle approximation you suggested.

Thanks for the reply! I was a bit confused since approximation was written for tan(X) = x and theta was define as atan(dy/dx) so I wasn't sure if we can just replace atan(dy/dx) with dy/dx. Somehow intuitively I expected an inverse which is dx/dy, but that is not how this works at all :) In fact, when I gave it a bit of thinking, I think if some function like tan(x) can be approximated faithfully with a linear function of unity slope, then per definition its inverse can as well be approximated by the linear function of the same slope, (for same range of small perturbations) since function y = f(x) = x is an inverse function of itself. Anyways, I've plotted in matlab both tan and atan around 0 and they look very much the same, so it all adds up :)

@@amirpasagic162 Plotting it out always helps me! I plotted it out in Wolfram before replying just to make sure

I think this translates roughly to "I don't understand"? Happy to help if you have any specific questions!