In your book, you mention that you use a Vortex Lattice software called SURFACES to calculate the change in lift coefficient with aileron deflection. 1. How/where can I download SURFACES? 2. How do you calculate the change in lift coefficient with aileron deflection? I do not understand the method shown in parenthesis in Example 23-1that loosely mentions some deflections used to calculate this coefficient. Also, this book is great! I know absolutely nothing about aircraft design yet I am using your book to design one :)
Hi Goldenfang 57: Thank you for your kind words. Here are your answers. (1) Download a tryout from: www.in-flightsimulation.com/product/surfaces-aircraft-design-cfd-software/ (2) Unfortunately, the answer requires understanding of aerodynamics and stability and control well beyond what can be expressed here. Sorry about that.
Hello Mr. Gudmendsson I was wondering is it practical for someone of my age (25) to get good at building aircraft by just reading your book, watching your videos, and practice building aircraft designs in 3D CAD software? I want to get good at building my own RC planes (then hopefully full fledged aircraft) using 3D printers and other materials I can gather on my own. Maybe even getting help from engineers with experience? I'd really rather not go to a 4 year school if I can avoid it. Your response is much appreciated
Hi Midwest Lgecay. Sorry about the delay in responding. My book has a lot of math in it as it is intended for engineers. If you're not interested in getting an engineering degree, the book is probably not the right choice (trust me, I take no pleasure in saying that). It all depends on what appeals to you. If you are more interested in hands-on activities, then perhaps you should consider A&P (Airframe & Powerplant - also called aircraft mechanic). It takes two years of schooling and gives you a lot of options for employment, primarily with the airlines. This would certainly train you in aircraft construction. There are a lot of highly specialized tools used in the aviation industry and if, later in your life, you are interested in building your own kitplane, you would certainly know enough to do that. Aircraft design requires a lot of math, although simple ultralights require far less math than larger and heavier ones. I certainly encourage you to design and build your own RC aircraft. It does not require a whole lot of math. But first you should learn to fly them. I started out with a slow flying electric glider. It's a top choice for beginners. This helps you getting a "feel" for what is required to design good aircraft, not to mention piloting them. Whatever your goals are, I strongly urge you to get the necessary education while you're young. It is all-too easy to say, "well, I'll do it next fall or next spring," and before you know it, you have lost a lot of time. Just get it out of the way and you're bound to have a long, steady, and well-paying job. I hope this helps. Best of luck to you!
Each curve (including the green line) is what is called an "isopleth" (a curve of some constant value). An "isobar," which you may have seen on a weather map, is one kind of an isopleth (it shows constant pressure over some geographic area). So, the green line means that any combination of W/S and T/W on the line results in the same T-O ground roll distance (e.g. 350 m). The blue isopleth shows all combinations of W/S and T/W the result in some constant rate-of-climb (e.g. 1000 ft/min). I hope this helps clarify. Best wishes.
@@dr.gudmundssonaircraftdesign thank you very much, it is much clear now. (1)Your book is the best in aircraft design. You explain every symbol used which a lot other books don't. You put a variable explanation table below every chapter which a lot other books don't. The helpful notes: HE GREEK ALPHABET, LIST OF ABBREVIATIONS AND COMMON TERMS....I hate to guess what does a symbol mean when looking at a book or video. I wish you can make more videos with clarity like your book. If you don't have time, would you please simple record your lectures in class like MIT open course? Yours are better than MIT professors. This will help us a lot and probably help to sell ur books. (2) For now, I want to get general understanding in aircraft design without reading the whole book. what chapters do you recommend me read or do I read 1st section of each chapter? or perhaps you can make these most essential and conceptual parts to videos. There are a lot of mechanical, car, aviation enthusiast like me will love it.
I have found this video very informative and I'm currently reading your book. However, I'm struggling to understand in your example calculation for the desired rate of climb where "80KCAS at S-L amounts to 135 ft/s" comes from. This seems like a very high rate of climb. I would really appreciate your response, thank you .
+James Morgan Hi James. I hope I am answering your question with the following: The 80 KCAS is not the Rate-of-Climb (ROC), but rather the airspeed at which the airplane climbs at 1500 fpm. Recall the ROC is a function of airspeed and the airspeed at which it reaches maximum is the "best ROC airspeed" or Vy. That is what the problem in the book (Problem 3-1) is dealing with. Does that answer your question?
+Professor Gudmundsson's Aircraft Design Channel Thank you very much for the reply Professor, I'm still struggling to understand how V is calculated, if the aircraft must be capable of climbing 1000fpm at 65KCAS at S-L. This gives Vv=16.7, what would the value of V be?
+James Morgan For propeller aircraft you could use Equation (18-27). Also re-read the paragraph below Equation (3-3). At this time you will actually have to make an "educated guess" about Vy. You can do this by researching what is common among the aircraft to which you compare your design. In fact, it looks like you have already done this with your V = 65 KCAS and Vv = 1000 fpm. Convert both to ft/s to obtain unit consistency. So, your Vv = 16.7 ft/s (like you show) and V = 65 x 1.688 = 109.7 ft/s (the coefficient 1.688 converts knots to ft/s). Hope this helps.
+Professor Gudmundsson's Aircraft Design Channel I really appreciate your response Professor, I finally understand it now! I think the confusion was due to the fact I usually work in SI units. Thank you very much for assisting me!
Very informative videos and am really happy and excited to have found your videos. (Thanks to google ML to have lead me to your channel😅) I was in a perception that Thrust / Weight should be always greater than 1(in terms of T>W means overcoming equilibrium). But it came as a shock to me when I discovered the commercial planes have T/W very much lesser than 1 (Source:Wikipedia). Could you please cast some light on this?
Hi Aushwath. Thank you for your question. T>W is only a requirement for VTOL (Vertical Take-Off and Landing). Yes, the reason why we fly fixed wing aircraft in the first place is that we only need thrust to equal drag, not weight. The forward motion develops L=W, while T=D and drag (D) is much less than lift (L). This is what makes fixed wing flight so much more efficient than VTOL. What is important to keep in mind is the rule: L/D=W/T. Sailplanes operate at very high L/D, around 20-50. This means that for level flight, they require thrust between 1/20 to 1/50 of their weight. Single engine trainer aircraft cruise at L/D around 8-11 and commercial jetliners around 12-16 or so. I hope this helps. Best wishes.
Hi sir, I've got a few questions. Context: I'm considering designing a WW2-era fighter aircraft and make it into a TH-cam series. I know some of what to expect since my final project in aerospace engineering was to do the conceptual design of a 12 PAX 650 nm aircraft (with Raymer and Roskam design books). Choosing specifications/mission, selecting the engine and plotting the constraint diagram with the climb, speed and turn radius curves won't be an issue. However, I don't know how I would estimate the wing weight and the fuselage weight. The equations given in Raymer/Roskam are for civil aircraft, while fighter aircraft are built to much higher loads, which would increase the wing weight over what the empirical equations would predict. For the fuselage, the equations again are for civil aircraft which are pressurized (and much bigger cross-section), so the empirical equations would predict a higher fuselage weight than what would actually be the case. Would you happen to have any advice for me regarding these weight issues (and any other issues if you happen to think of any while reading this)? Thanks in advance!
It is not easy to estimate component weight of WWII era aircraft. Manufacturers of that time did not leave a lot of hints behind. Regardless, today, we know a lot more about how to design aircraft than what was known in that time. So here are guesses; I would expect the wing and fuselage weight of WWII era aircraft to be less or equal to 15% of gross weight, each. Unfortunately, I can't provide greater accuracy. That said, properly utilizing today's knowledge of aircraft design, you should be able to design an airframe that weighs slightly less than these aircraft. Luckily, this will not prevent you from loading your design to match the gross weight.
@@dr.gudmundssonaircraftdesign Thanks for the answer! I found 1 "detailed" (rounded to nearest 50lb) weight breakdown for the P51 Mustang, which supports your 15% rule of thumb for wings and fuselage. Hopefully I can find some more weight breakdowns. If not, I'll use modern empirical wing weight equations to predict the wing weight of the P51 and compare with the real wing weight, and find the factor that separates the 2 values for future wing weight estimates.
I love your book about aircraft design, but at one point i have a big problem to understand the design process. In initial sizing phase we have to calculate the T/W for a desired RoC. There we need airspeed and vertical speed to calculate the T/W. We don`t know those two parameters and if we want to calculate them, we need to know the wing loading, which ist also unknown? You describe a method which is using historical trends for the best rate-of-climb speed, but this needs W/S too? I don`t know where i have to start if i want to calculate the T/W for RoC for an airplane with electric driven propellers with more then two engines.
What you need to do is to use a spreadsheet. Create a table where the first column has a range of W/S. For instance, make the first W/S be, say, 5 lbf/ft², the next one 6, and then 7, 8, 9,...etc, perhaps stopping at 40 lbf/ft². Then calculate Vy for each of these W/S values, and then the appropriate values of T/W for ROC (what is the ROC you are targeting? 600 fpm? 1500 fpm?). Plot these numbers using T/W as your y-value and W/S as your x-value. Then, repeat for all the other T/W values of interest. Yes, you don't know what W/S you need...at first. The purpose of the method IS to find a proper W/S that satisfies all your requirements. This is reflected in all the T/W values you plotted. To do this, you must know how to read the graph. In general for GA aircraft, look for the lowest W/S and lowest T/W for low speed aircraft and highest W/S and lowest T/W for high performance aircraft. I hope this helps.
You're welcome, Alexandra. I have yet to make a video on V-n diagrams. I'll consider it for future projects. In the meantime, I have a Step-by-Step on how to make one in Chapter 16 in my book. Best wishes.
Fundamentally, we want to extract the wing area and engine size for the aircraft using the constraint diagram. Both of these can be extracted if we can estimate a likely weight for the airplane. We start with the T/W because it gives the required thrust directly from the expression T = (T/W)∙W. This is basically all you need to select a suitable turbojet or turbofan. However, for propeller aircraft we must take one extra step and convert this thrust to power, using expected propeller efficiency at each flight condition. Thus, it is logical to also start with the T/W there as well. Of course, it is possible to develop P/W-expression directly, but this is not very common in my experience. So, in most books, only T/W-expressions are used. I hope this clarifies.
Is the optimum design point always the one that, laying inside of the acceptable region, has the lowest T/W ratio? Having a high W/S ratio might improve the aircraft's response to gusts. Hence, what about the intersection point of the green and blue curves, would that be another optimum point?
+jibeneyto All the intersections on the edge of the acceptable region are optimums. Typically, the one with the lowest T/W is the best since it has a chance of getting you the lightest and least expensive power plant. And the lower W/S lowers your stalling speed (and shorter T-O/ldg distances) over higher W/S and, thus, is desirable. Yes, you are correct about higher W/S giving better "ride" in turbulence and if this is more important to you than the lower stalling speed, then it is your perogative to select it over the lower W/S. I hope this helps.
+Professor Gudmundsson's Aircraft Design Channel Thanks for your response Professor. Could we say, as a generalization, that light aircraft aim towards the lowest T/W ratio, while transport category aircraft aim for the higher W/S ratio in order to increase passenger comfort?
+jibeneyto Yes, this would be possible to state for GA aircraft. However, one must be careful to state the opposite for commercial aircraft. There are simply too many different constraints to consider. While high W/S is desirable for ride quality, it is detrimental for other requirements, such as T-O and landing distances, cruise drag (since such aircraft cruise at similar Mach number, higher W/S leads to higher drag and higher fuel costs), and likely cost of powerplant. So, yes, ride quality is important, as long as other constraints are considered too and the right balance is struck.
+Professor Gudmundsson's Aircraft Design Channel Thanks for your kind response! And please, keep uploading such interesting videos on aircraft design! :)
Absolutely. Common mistakes: Underestimation of CDmin and overestimation of CLmax and propeller efficiency. Small props have small max prop efficiency. Expect a maximum of the order of 0.45-0.55. Check Dr. Selig's research at UofIllinois for more details. Good luck and best wishes!
Yes, Rob, I had heard. It's sucks rocks. However, if you notice, there are important pages missing. All of them contain the very secrets of a successful design, so I suggest you buy the real thing. It's available from amazon.com. Cheers!
@@dr.gudmundssonaircraftdesign Hey Dr, I did go looking for a place I could buy it, but unfortunately I can't justify spending over $100 on an ebook, i'm only a hobbyist. It does look very good though
Outside of my book (and some other design texts) and a few academic papers there is surprisingly little on general design of fuselages. You may find "non-math" texts aimed at homebuilders (e.g. TAB books). You can also look at the fuselage design discussion in David Thurston's book "Design for Flying." If you have a specific question, I can try and answer it here.
Thank you Dr.Gudmundsson, it is very helpful video
@user-zr5vi9zg4c You're welcome. Glad to read you think so. Best wishes.
In your book, you mention that you use a Vortex Lattice software called SURFACES to calculate the change in lift coefficient with aileron deflection.
1. How/where can I download SURFACES?
2. How do you calculate the change in lift coefficient with aileron deflection? I do not understand the method shown in parenthesis in Example 23-1that loosely mentions some deflections used to calculate this coefficient.
Also, this book is great! I know absolutely nothing about aircraft design yet I am using your book to design one :)
Hi Goldenfang 57: Thank you for your kind words. Here are your answers.
(1) Download a tryout from: www.in-flightsimulation.com/product/surfaces-aircraft-design-cfd-software/
(2) Unfortunately, the answer requires understanding of aerodynamics and stability and control well beyond what can be expressed here. Sorry about that.
Thank you for your quick reply! Is there any literature you can direct me to that will thoroughly explain the concept? @@dr.gudmundssonaircraftdesign
Yes your channel is unique as your knowledge, really brilliant sir please teach on edx, or here thanks for having heare to teach,...
Thank you for your kind comment. Best wishes.
Hello Mr. Gudmendsson
I was wondering is it practical for someone of my age (25) to get good at building aircraft by just reading your book, watching your videos, and practice building aircraft designs in 3D CAD software? I want to get good at building my own RC planes (then hopefully full fledged aircraft) using 3D printers and other materials I can gather on my own. Maybe even getting help from engineers with experience? I'd really rather not go to a 4 year school if I can avoid it. Your response is much appreciated
Hi Midwest Lgecay. Sorry about the delay in responding. My book has a lot of math in it as it is intended for engineers. If you're not interested in getting an engineering degree, the book is probably not the right choice (trust me, I take no pleasure in saying that). It all depends on what appeals to you. If you are more interested in hands-on activities, then perhaps you should consider A&P (Airframe & Powerplant - also called aircraft mechanic). It takes two years of schooling and gives you a lot of options for employment, primarily with the airlines. This would certainly train you in aircraft construction. There are a lot of highly specialized tools used in the aviation industry and if, later in your life, you are interested in building your own kitplane, you would certainly know enough to do that. Aircraft design requires a lot of math, although simple ultralights require far less math than larger and heavier ones. I certainly encourage you to design and build your own RC aircraft. It does not require a whole lot of math. But first you should learn to fly them. I started out with a slow flying electric glider. It's a top choice for beginners. This helps you getting a "feel" for what is required to design good aircraft, not to mention piloting them. Whatever your goals are, I strongly urge you to get the necessary education while you're young. It is all-too easy to say, "well, I'll do it next fall or next spring," and before you know it, you have lost a lot of time. Just get it out of the way and you're bound to have a long, steady, and well-paying job. I hope this helps. Best of luck to you!
@8:35, why the green line represent take off distance since y axis=T/W and x axis=W/S?
Each curve (including the green line) is what is called an "isopleth" (a curve of some constant value). An "isobar," which you may have seen on a weather map, is one kind of an isopleth (it shows constant pressure over some geographic area). So, the green line means that any combination of W/S and T/W on the line results in the same T-O ground roll distance (e.g. 350 m). The blue isopleth shows all combinations of W/S and T/W the result in some constant rate-of-climb (e.g. 1000 ft/min). I hope this helps clarify. Best wishes.
@@dr.gudmundssonaircraftdesign thank you very much, it is much clear now.
(1)Your book is the best in aircraft design. You explain every symbol used which a lot other books don't. You put a variable explanation table below every chapter which a lot other books don't. The helpful notes: HE GREEK ALPHABET, LIST OF ABBREVIATIONS AND COMMON TERMS....I hate to guess what does a symbol mean when looking at a book or video. I wish you can make more videos with clarity like your book. If you don't have time, would you please simple record your lectures in class like MIT open course? Yours are better than MIT professors. This will help us a lot and probably help to sell ur books.
(2) For now, I want to get general understanding in aircraft design without reading the whole book. what chapters do you recommend me read or do I read 1st section of each chapter? or perhaps you can make these most essential and conceptual parts to videos. There are a lot of mechanical, car, aviation enthusiast like me will love it.
I have found this video very informative and I'm currently reading your book. However, I'm struggling to understand in your example calculation for the desired rate of climb where "80KCAS at S-L amounts to 135 ft/s" comes from. This seems like a very high rate of climb. I would really appreciate your response, thank you .
+James Morgan Hi James. I hope I am answering your question with the following: The 80 KCAS is not the Rate-of-Climb (ROC), but rather the airspeed at which the airplane climbs at 1500 fpm. Recall the ROC is a function of airspeed and the airspeed at which it reaches maximum is the "best ROC airspeed" or Vy. That is what the problem in the book (Problem 3-1) is dealing with. Does that answer your question?
+Professor Gudmundsson's Aircraft Design Channel Thank you very much for the reply Professor, I'm still struggling to understand how V is calculated, if the aircraft must be capable of climbing 1000fpm at 65KCAS at S-L. This gives Vv=16.7, what would the value of V be?
+James Morgan For propeller aircraft you could use Equation (18-27). Also re-read the paragraph below Equation (3-3). At this time you will actually have to make an "educated guess" about Vy. You can do this by researching what is common among the aircraft to which you compare your design. In fact, it looks like you have already done this with your V = 65 KCAS and Vv = 1000 fpm. Convert both to ft/s to obtain unit consistency. So, your Vv = 16.7 ft/s (like you show) and V = 65 x 1.688 = 109.7 ft/s (the coefficient 1.688 converts knots to ft/s). Hope this helps.
+Professor Gudmundsson's Aircraft Design Channel I really appreciate your response Professor, I finally understand it now! I think the confusion was due to the fact I usually work in SI units. Thank you very much for assisting me!
Very informative videos and am really happy and excited to have found your videos. (Thanks to google ML to have lead me to your channel😅)
I was in a perception that Thrust / Weight should be always greater than 1(in terms of T>W means overcoming equilibrium). But it came as a shock to me when I discovered the commercial planes have T/W very much lesser than 1 (Source:Wikipedia).
Could you please cast some light on this?
Hi Aushwath. Thank you for your question. T>W is only a requirement for VTOL (Vertical Take-Off and Landing). Yes, the reason why we fly fixed wing aircraft in the first place is that we only need thrust to equal drag, not weight. The forward motion develops L=W, while T=D and drag (D) is much less than lift (L). This is what makes fixed wing flight so much more efficient than VTOL. What is important to keep in mind is the rule: L/D=W/T. Sailplanes operate at very high L/D, around 20-50. This means that for level flight, they require thrust between 1/20 to 1/50 of their weight. Single engine trainer aircraft cruise at L/D around 8-11 and commercial jetliners around 12-16 or so. I hope this helps. Best wishes.
Hi sir,
I've got a few questions.
Context: I'm considering designing a WW2-era fighter aircraft and make it into a TH-cam series. I know some of what to expect since my final project in aerospace engineering was to do the conceptual design of a 12 PAX 650 nm aircraft (with Raymer and Roskam design books). Choosing specifications/mission, selecting the engine and plotting the constraint diagram with the climb, speed and turn radius curves won't be an issue.
However, I don't know how I would estimate the wing weight and the fuselage weight. The equations given in Raymer/Roskam are for civil aircraft, while fighter aircraft are built to much higher loads, which would increase the wing weight over what the empirical equations would predict. For the fuselage, the equations again are for civil aircraft which are pressurized (and much bigger cross-section), so the empirical equations would predict a higher fuselage weight than what would actually be the case. Would you happen to have any advice for me regarding these weight issues (and any other issues if you happen to think of any while reading this)?
Thanks in advance!
It is not easy to estimate component weight of WWII era aircraft. Manufacturers of that time did not leave a lot of hints behind. Regardless, today, we know a lot more about how to design aircraft than what was known in that time. So here are guesses; I would expect the wing and fuselage weight of WWII era aircraft to be less or equal to 15% of gross weight, each. Unfortunately, I can't provide greater accuracy. That said, properly utilizing today's knowledge of aircraft design, you should be able to design an airframe that weighs slightly less than these aircraft. Luckily, this will not prevent you from loading your design to match the gross weight.
@@dr.gudmundssonaircraftdesign Thanks for the answer!
I found 1 "detailed" (rounded to nearest 50lb) weight breakdown for the P51 Mustang, which supports your 15% rule of thumb for wings and fuselage. Hopefully I can find some more weight breakdowns. If not, I'll use modern empirical wing weight equations to predict the wing weight of the P51 and compare with the real wing weight, and find the factor that separates the 2 values for future wing weight estimates.
I love your book about aircraft design, but at one point i have a big problem to understand the design process. In initial sizing phase we have to calculate the T/W for a desired RoC. There we need airspeed and vertical speed to calculate the T/W. We don`t know those two parameters and if we want to calculate them, we need to know the wing loading, which ist also unknown? You describe a method which is using historical trends for the best rate-of-climb speed, but this needs W/S too? I don`t know where i have to start if i want to calculate the T/W for RoC for an airplane with electric driven propellers with more then two engines.
What you need to do is to use a spreadsheet. Create a table where the first column has a range of W/S. For instance, make the first W/S be, say, 5 lbf/ft², the next one 6, and then 7, 8, 9,...etc, perhaps stopping at 40 lbf/ft². Then calculate Vy for each of these W/S values, and then the appropriate values of T/W for ROC (what is the ROC you are targeting? 600 fpm? 1500 fpm?). Plot these numbers using T/W as your y-value and W/S as your x-value. Then, repeat for all the other T/W values of interest. Yes, you don't know what W/S you need...at first. The purpose of the method IS to find a proper W/S that satisfies all your requirements. This is reflected in all the T/W values you plotted. To do this, you must know how to read the graph. In general for GA aircraft, look for the lowest W/S and lowest T/W for low speed aircraft and highest W/S and lowest T/W for high performance aircraft. I hope this helps.
Thank you for your video. Do you have sth about V-n diagram? :)
You're welcome, Alexandra. I have yet to make a video on V-n diagrams. I'll consider it for future projects. In the meantime, I have a Step-by-Step on how to make one in Chapter 16 in my book. Best wishes.
Hi!
Why do we always begin the process with the thrust-to-weight ratio?
Fundamentally, we want to extract the wing area and engine size for the aircraft using the constraint diagram. Both of these can be extracted if we can estimate a likely weight for the airplane. We start with the T/W because it gives the required thrust directly from the expression T = (T/W)∙W. This is basically all you need to select a suitable turbojet or turbofan. However, for propeller aircraft we must take one extra step and convert this thrust to power, using expected propeller efficiency at each flight condition. Thus, it is logical to also start with the T/W there as well. Of course, it is possible to develop P/W-expression directly, but this is not very common in my experience. So, in most books, only T/W-expressions are used. I hope this clarifies.
Is the optimum design point always the one that, laying inside of the acceptable region, has the lowest T/W ratio? Having a high W/S ratio might improve the aircraft's response to gusts. Hence, what about the intersection point of the green and blue curves, would that be another optimum point?
+jibeneyto All the intersections on the edge of the acceptable region are optimums. Typically, the one with the lowest T/W is the best since it has a chance of getting you the lightest and least expensive power plant. And the lower W/S lowers your stalling speed (and shorter T-O/ldg distances) over higher W/S and, thus, is desirable. Yes, you are correct about higher W/S giving better "ride" in turbulence and if this is more important to you than the lower stalling speed, then it is your perogative to select it over the lower W/S. I hope this helps.
+Professor Gudmundsson's Aircraft Design Channel Thanks for your response Professor. Could we say, as a generalization, that light aircraft aim towards the lowest T/W ratio, while transport category aircraft aim for the higher W/S ratio in order to increase passenger comfort?
+jibeneyto Yes, this would be possible to state for GA aircraft. However, one must be careful to state the opposite for commercial aircraft. There are simply too many different constraints to consider. While high W/S is desirable for ride quality, it is detrimental for other requirements, such as T-O and landing distances, cruise drag (since such aircraft cruise at similar Mach number, higher W/S leads to higher drag and higher fuel costs), and likely cost of powerplant. So, yes, ride quality is important, as long as other constraints are considered too and the right balance is struck.
+Professor Gudmundsson's Aircraft Design Channel Thanks for your kind response! And please, keep uploading such interesting videos on aircraft design! :)
+jibeneyto You're welcome. And thank you for your kind words about this work. :-)
Thank you!
You're welcome.
Thanks for your book professor. One question. On page 78 in it, you mention "Appendix C" - provided on line. Could you point where's the link for it?
Yes, you should be able to download it from booksite.elsevier.com/9780123973085/appendices.php
Dear Dr., can I use this Constraint Diagram for Small Prop-Driven UAV?
Absolutely. Common mistakes: Underestimation of CDmin and overestimation of CLmax and propeller efficiency. Small props have small max prop efficiency. Expect a maximum of the order of 0.45-0.55. Check Dr. Selig's research at UofIllinois for more details. Good luck and best wishes!
@@dr.gudmundssonaircraftdesign Thank you very much, Dr.
Good video Dr. I am living in Cameroon 🇨🇲. How can i get your book ?
Thank you. The book is available on the Elsevier website, amazon.com, and frankly, most outlets of books online. Best wishes!
Hey peeps, you didn't hear this from me, but if you want to check out Dr G's book it's available on google books to read for free
Yes, Rob, I had heard. It's sucks rocks. However, if you notice, there are important pages missing. All of them contain the very secrets of a successful design, so I suggest you buy the real thing. It's available from amazon.com. Cheers!
@@dr.gudmundssonaircraftdesign Hey Dr, I did go looking for a place I could buy it, but unfortunately I can't justify spending over $100 on an ebook, i'm only a hobbyist. It does look very good though
Any online material on fuselage design?
Outside of my book (and some other design texts) and a few academic papers there is surprisingly little on general design of fuselages. You may find "non-math" texts aimed at homebuilders (e.g. TAB books). You can also look at the fuselage design discussion in David Thurston's book "Design for Flying." If you have a specific question, I can try and answer it here.
@@dr.gudmundssonaircraftdesign (UAV) Fuselage loading action and sizing...I need details on how to go about these.
Yes, understand. Unfortunately, the answers to those questions require much more than what can be answered here. Sorry about that, mate.
Yeah Mr. White! Yeah Science!