An important evolution from the slides that were shown in class (v1.0). This document does a much better job of presenting the course as a whole, its objectives and limitations.
I wrote an important set of accompanying remarks on my blog regarding the course as a whole; a series of blog posts will follow, hopefully giving insights on the projects themselves, and how they went.
The slides and projects are very nearly similar to those shown in class in March (v1.0). I made minor modifications and replaced a few proprietary photos with free ones.
Authors whose work is used in these slides:
The slides are very nearly identical to those used in class last March (v1.0).
This project was by far the hardest of the course. A whole set of comments accompanies this release on my blog (your comments are welcome!).
Media used in these documents:
The following photos would be in the slides if they were free... I tried to purchase these shots to put them on Wikipedia but could not get in touch with the photographers. Any help getting in contact with these people would be very appreciated.
Documents I created that will be published on the Commons later this year:
A very rich lecture and an interesting, if rather unsuccessful, project. See my commentary about this project on my blog.
Many improvements, indeed far too many to list here, were brought to the slides since they were first used in class (v1.0).
Media used in these documents:
The following photos would be in the slides if they were free... I tried to purchase these shots to put them on Wikipedia but could not get in touch with the photographers. Any help getting in contact with these people would be very appreciated.
Documents I created that I then published on the Commons:
Documents I created that will be published on the Commons later this year:
The shortest and simplest lecture in the whole series, and quite a successful one as well. A set of comments accompanies this release on my blog.
Media used in these documents:
Documents I created that will be published on the Commons later this year:
Quite a hefty lecture, that will need some clean-up next year. An enormous amount of material was created for these slides.
A set of remarks accompanies this release on my blog.
Other people’s work used in these slides:
Public Domain media scanned/reworked from books and contributed back:
Derivative works:
Media built for this lecture and released on the Wikimedia Commons:
Media built for this lecture, not yet released:
The beutiful 1904 drawings by Ludwig Prandtl are not published on the Commons, because although they are public domain in the USA (published before 1923) they are not in Germany (Prandtl died in 1953). +70 years brings us to August 2023!
A rather conformal and straightforward lecture and project. A set of remarks accompanies this release on my blog.
Other people’s work used in these slides:
Media built for this lecture, that will be released later on this year:
This lecture features guest lecturer Hamassala David Dicko who also shares authorship for the lecture source files.
It must be noted that several data in the project appendix, such as the wing root dimensions, are wrong by a factor of more than two. We found this out too late in the project set-up process to be able to correct them (this will be done for the next edition). The overall meaning and solving process in the project are not affected.
This was quite an outstanding lecture, and a rather modest project. A set of remarks accompanies this release on my blog.
Media used in this release:
Many drawings were created for the purpose of this lecture but I don’t see any being published on the Wikimedia Commons (they only make sense within the context of a course).
The last project of the series, and one which leaves me rather statisfied. As usual, a set of comments accompanies this release on my blog, and conclusions will wrap up the whole saga tomorrow.
Media used in this release:
Media I authored, that are used in this lecture and will be released on the Commons later this year:
Next up, conclusions, and then we are finally done!
Minor changes only for this edition. I am simply insisting more on the importance of quantifying drag as a function of speed – and thus stressing the difference between ground and air vehicles in this respect.
In an effort to adapt to the students’ tastes, project 1, previously focused on a 320NEO, now features a stretched 380 (yikes!).
I skipped straight to project 4 (in the second class session) in an effort to help a few students get back on track. Project 4 is by far the easiest of the series; that should help soothe things out.
Virtually no change in the project (if it ain’t broken...). I removed the theoretical part (derivation of the Breguet range equation), which was covered as part of the lecture.
Added historical note about Lilienthal (this worked well in class);
Added Payload-range for the P-180 Avanti (I am buying one of those as soon as I can afford it);
Covered the Breguet range equation in the slides (rather than in the project).
Minor modification to the illustration
Clarified slides about drag as a function of speed ("Power and Speed on the Ground" section)
Re-drew helicopter and aircraft schematics used to illustrate downwash;
Clearer description of project at end of slides.
The structure and content of the lecture are almost unchanged. I did take the time, however, to re-draw a number of figures. The transition from 2D to 3D-lift (using the lifting-line theory), which I see as a pinnacle of the course, is better described and gives me full satisfaction.
The volume of slides has grown again and this worries me; chances are this lecture won’t quite fit within the 2,5 hr slot. Since the only content within the lecture which is critical to the project is the vocabulary, I will likely skip some parts as I go this week.
I simply changed the aircraft size from 150-pax to 400-pax and clarified the text a little.
Very little change in this edition. I would love to move to the study of nozzles, but I must do both with my own personal constraints at this time, and with the very uneven level of the class. It is better to go with proven content and projects right now.
I have moved away from the (very good) Barnard & Philpott example for propulsive efficiency, constructing my own example with the Dornier 328. Since the aircraft was built and flown with two different engine types, it is a perfect example in this matter. This keeps me clear from copyright infringement, and also back into my beloved civilian area.
The project (Turbofan Design) is left entirely unchanged.
The majority of the lecture sees only minor updates here; however, we made important mistakes in the last part ("A pilot’s perspective"). While our conclusions were correct, the explanations leading to them were not.
In this case, the center of pressure on a airfoil does not in fact move when speed is increased at constant attitude, regardless of whether it is cambered or not. An increase in speed at constant attitude (such as during a gust) would neither change the elevator neutral position, nor cause a net moment around the aircraft center of gravity.
It turns out that the reason why aircraft pitch towards their "trim tab setting speed" is much simpler. Any change in speed needs be compensated by a change in attitude; that in turns changes the lift force on the tail. This change must be compensated by the elevator, either with pilot control input or with the help of a new trim tab setting. Failure to compensate the net change on the tail force (by letting go of the controls) will result in the aircraft pitching. A quick sketch will reveal that the aircraft will pitch down if slowed down, up if accelerated. I hope the slides explain this clearly now.
No change at all since last year. I am still unsatisfied with the data and know some of it to be erroneous (in particular the mean aerodynamic chord). But I lost the source for the corrected information, and now lack the time to experiment with this ("if it ain’t broken").
Corrected a typo (the turbine power is in kJ/kg not J/kg).
Corrected a rather prejudicial typo in the quantification of root circulation for an elliptical lift distribution wing, at slide #93. Added slide numbering.
New diagrams to illustrate the concepts of static vs. dynamic (longitudinal) stability. They replace scans from the (most excellent) Engmann et al. 1994.
Minor re-wordings throughout the slides.
Minor re-wordings and improvement to the illustration. No substantial change.
I have explored the concept of airfoil aerodynamic moment coefficient in a much more rigorous way. In addition to the constant-speed (wind-tunnel) experiments, I have now drawn diagrams for the constant-lift (aircraft flight) case. This is much more satisfactory for several reasons:
This brings into light the relevance of using coefficients for forces and moments, rather than just the plain values;
This "wind tunnel" vs. "aircraft flight" (constant speed vs. constant lift) distinction is an important, difficult one – I wish we would more systematically insist on it in books and lectures.
Overall, an improvement I am particularly satisfied with. My understanding of the phenomenon certainly grew while drawing this out.
A minor update overall.
The hand-out for project 1 will be uploaded shortly.
New version of the project, this time based on the half-failed Eclipse 500 twinjet.
Inconsequential changes from the version used last year.
Minor changes relative to 2011 when I last gave this lecture.
Minor tweaks to the section on the Lanchester-Prandtl lifting-line theory
Changed aircraft to a four-engined mystery airliner.
Minor formatting changes.
Minor changes only.
Changed engine to a military afterburning turbofan, as per the request of a student. This required considerable work, since the constraints (known mass flow) are quite different. I hope this turns out well!
I think both the lecture and the project have reached a satisfactory level of maturity. This year they required almost no change.
Minor updates to the key slides about efficiency, in an attempt to clarify the difference between the general case and the specific case of a turbojet. I was not clear enough this time (or, as I like to think, simply too quick during the lecture) and important mis-interpretations cropped up in the students’ reports.
Just as last week: this project and the associated slides have reached a rather comfortable level of maturity and required almost no change since last year.
A new lecture and project inspired by the Solar Impulse project. There are a million ways this project can fail, so I shall wait before commenting.
Update May 8th, 2013: The files are now back offline. The session was a success but I feel the projects are too inaccurate to be published online. Next year I will give this topic much more coverage.
Minor update (financial data updated, typo fixed)
_03.jpg){kind=link}
.PNG){kind=link}
_taxiing_at_EKRN_(Bornholm_airport).jpg){kind=link}
