In case it is helpful, here are all the Flight Mechanics videos in a single playlist ruclips.net/p/PLxdnSsBqCrrEx3A6W94sQGClk6Q4YCg-h. You can support this channel via Patreon at www.patreon.com/christopherwlum. Please let me know what you think in the comments. Thanks for watching!
Thank you Prof. Lum. It is nice to have your videos of talking about the flight mechanics. For the nonlinear 6 DOF dynamic model, I expected something about the term ω ⃗×H ⃗, where H ⃗=(I_x p,I_y q,I_z r) which will cause nonlinear pitch instability as shown in my video: ruclips.net/video/gG2-mu6I11A/видео.html. I believe this nonlnear pitch instability is the root cause for two recent 737 Max crashes. You can also found my presentation about this claim at Slide 13 in www.aiaahouston.org/Horizons/ATS2019-Presentation-SS-Tang.pdf. I appreciate your thought about this phenomenon. Steve Tang
AE 512: Very cool to see all the different expressions we've developed in the last few weeks finally used to simulate the aircraft dynamics. Great video!
I'm glad it was helpful. There are several related videos on the channel. Please feel free to check them out and I would love to hear what you think in the comments. Thanks for watching!
Haha, I know, it would be great if we could simple models like this 😀. That being said, it is interesting to see what type of behavior is actually captured in this somewhat simplified model. We should talk on the other side about it, there are some things you might find interesting...
AA516 - I really enjoyed these RCAM videos. I had come across them for a couple years and always thought they looked cool. They are a large part of the reason I wanted to take this class. I added a basic 2D autopilot to mine, but want to use PID controllers to make a fly-by-wire system.
AA516: I am looking forward to seeing the Simulink implementation! Even before implementing, it helps me to think of this in terms of the blocks diagrams
Hi Thomas, I'm glad it was helpful. There are other similar videos on the channel, please feel free to check them out and let me know what you think in the comments. Thanks for watching and I hope to catch you at another video.
AE512: Great lecture, especially when we combine all the hard work into a state vector (i.e a system we can simulate via simulink). Spoiler for the next video!
Hi Christopher, thanks a lot for that very detailed and understandable explanation of the model! But at one point I got a little confused about the values used. At 25:25 alpha_L0 is defined as negative 11.5*pi/180 but later at 38:45 you used positive 11.5*pi/180 as alpha_L0 which actually matches the value which I found in the RCAM publication. I am thankful for any further explanation!
Hi Markus, thanks for catching that. I believe the correct value is -11.5*pi/180 so I made a mistake/typo at 38:45. I believe the RCAM document lists -11.5*pi/180 as the proper value. Out of curiosity, where did you find the RCAM publication? Can you send me the URL or link to the location of where you obtained the document.
@@ChristopherLum Alright, the negative value is much more sensible though. Here (garteur.org/wp-content/reports/FM/FM_AG-08_TP-088-3.pdf) I found a report on the RCAM model on the Garteur website where it says alpha_L0 is the positive value, but what confuses me is that the publication is from 1995 instead of 1997 but it has exactly the same title and the rest also seems pretty much the same.
@@dimitris.159 Markus, thanks for the link. It looks like the 1995 version has the typo/mistake that we are discussing. It was fixed in the 1997 version.
I know, it is great to finally capitalize on all the previous background knowledge to actually build something. I'm excited to see what you do for your final project!
I'm glad it was helpful. There are similar videos at ruclips.net/p/PLxdnSsBqCrrEx3A6W94sQGClk6Q4YCg-h. Please feel free to check them out and let me know what you think, thanks for watching!
I have a challenge for you. This model assumed that the airplane was flying in still air. Air is rarely still, it has updrafts, downdrafts and wind. I'd love to see how you add wind to the 6 DOF model. I have some ideas of my own, but I'd like to see how you would do it. Thanks !
AA 516: Really cool to see all the content from previous lecture come together in the RCAM model! Regarding the equation we derived for the AoA of the tail, I did not quite understand the reasoning behind why one of the terms was proportional to the pitch rate and horizontal distance to the tail. This discussion was at the 41:30 mark.
Miles, good question. This is simply how they chose to model the dynamic pitch dampening effect of the tail. This is attempting to add behavior which makes it difficult to pitch the vehicle at a high rate. When q is large this creates a large AoA of the tail which in turn actually creates a negative pitching moment which counteracts the pitch rate. You could get a similar effect by adding this to the moment equation but for whatever reason, they chose to model it here. Let me know if you want to chat more about this at office hours.
I'm glad it was helpful. There are several related videos on the channel. Please feel free to check them out and I would love to hear what you think in the comments. Thanks for watching!
Hi Christopher, thanks for your wonderful videos. I have been looking for the document (GARTEUR TP-0883) On the web page, but I cant found it. please if you have a link where I can found it, let me know greetings from Ecuador
May I know where is the link to the "The Flat Earth Equations of Motion for a Rigid Body" video as mentioned in 0:11? I have been searching all the videos on your channel but still can't find it.
I'm glad it was helpful. There are other similar videos on the channel please feel free to check them out and let me know what you think in the comments. Thanks for watching!
Hi. Thank you for making this detailed lecture series. I have a question. When rolling through 180 deg, the roll plot typically does "weird" stuff. What I observe is that say it is a positive roll, around 180 degree it suddenly drops to the negative side and continues increasing. Why do we observe this behavior. It also makes the pitch result very unbelievable. How does one interpret the data?
AA516: In industry, do engineers typically start with something like this simplified model and add onto it? Or is it too hard to complicate an existing model such that it's better to start complex and end complex?
Hello dear teacher I am following your lessons Could you upload the video lesson 'the flat earth equations of motion for a Rigid body 'you mentioned at the beginning? Healthy Days...
AE 512: I'm curious how the stability/body typos you point out in the 1997 paper would affect implementing the model, my sense is under cruising conditions it won't do much but on takeoff/landing it could cause some real screwy behavior.
You're probably right. In many circumstances the stability and body axes are similar but in off nominal cases it could affect the system significantly.
Dear Lum and audiences: I cannot get access to the 1997 ver. document but only 1995 ver. on the website. Is there anyone can post a 1997ver. link or send me the relevant document. Lots of thanks @Christopher Lum
first i would like to present my gratitude for ur very helpfull lectures i have ever seen. next i would like u to give me the link for 2 videos; 1. "The Flat Earth Equations of Motion for a Rigid Body" 2. "Equations of motion for a planar vehicle"
Hi, Dr. Christopher Lum I hope you are fine. I enjoy the tutorials you post on your RUclips channel and I thank you. I am very interested in studying the field of tilt-rotor drones. But I didn't get a proper understanding of these types of drones through the articles. Can you help me to understand the model of this type of drones? Can you provide me with an instructional video or a resource that explains the modeling of these drones in detail? thank you.
Hi, Thanks for reaching out. If you have questions or would like to request a video, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video. I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching! -Chris
AE 512: Coming back from the next video, at 1:03:37 I believe there is a typo on the board for dCM/dx, it should have cbar^2 in the denominator of the middle term.
[AE 512] 1:23:47 Why is the throttle put in terms of degrees? Shouldn't it be in terms of percentage. I am having trouble visualizing a throttle setting in degrees or radians?
As usual with this channel, wonderful explanation once again. It is indeed amazing that the complex 6 DOF model is explained in such an easy to understand language. Thank you Dr. Lum for creating such content. I have a small query here at approx 01:22:27. The moments automatically are represented in body frame. However, what if 6 DOF simulation model is prepared in wind-frame? Does moments need to be transferred from body to wind frame? Once again, thank you for creating the Flight mechanics channel.
Hi, Thanks for reaching out, I'm glad you enjoyed the video. Unfortunately I'm unable to respond to questions on RUclips due to the sheer volume of inquiries that I receive. That being said, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum as I'll be able to answer questions there. Given your interest in the topic, I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching! -Chris
@@ChristopherLum Thank you for your response, Dr. Lum. I will surely become your patron when I become a professor in the Aerospace department in a couple of years.
Is it possible to do this for any aircraft? I’m looking to do a dynamic model for the Cirrus SR22 but without documentation as easily available (from what I’ve seen) such as that you referenced from the Aeronautical Research, is it feasible?
1:05:32 Isn't Pitching Moment about aerodynamic center independent of alpha? Or is that in a different frame? ^The Aerodynamic center is the point at which the pitching moment coefficient for the airfoil does not vary with lift coefficient (i.e. angle of attack) en.wikipedia.org/wiki/Aerodynamic_center. Which frame is the wiki article referring to?
I'm glad it was helpful. There are other similar videos on the channel. Please feel free to check them out and let me know what you think. Thanks for watching!
Hi Sunny, your timing is perfect, we were just talking about this at office hours an hour ago. Once this gets published please check it out and let me know if this makes sense.
@@ChristopherLum Hi Chris, I am not sure I am seeing the video you are referencing. Where should I be looking for it? I can't see a cloud recording on Canvas and unfortunately, I could not make office hours last night.
AA516 - Hello Professor Lum, I noticed in the following video where we build the RCAM model in MATLAB, you have a squared term for the cbar variable in the dCMdx formula at 1:07:44 . In this video however, you don't have the squared term. Is this a typo?
When in double, go with the notes, it is likely I missed something when writing it on the board. Did you check against the RCAM document? Can you tell me which one appears to have the error?
@@ChristopherLum Yes, the RCAM document shows the cbar variable squared on page 17, so the error would be in this video not having the squared cbar for dCMdx. Thanks for the response!
Should the mu in the engine moment equation about the CG be (r_APTi - r_CG) instead of (r_CG - r_APTi) (at 1:30:00, not sure why the y element in mu is different either)? The value for ZAPTi probably should be positive instead of negative. The combination of these two errors save the day and generates acceptable final results.
EDIT: NVM, I saw that the table 2.4 is NOT at the body frame. Original: At around 1:30:37 you said that the moment due to the engine is cross (mu , Fe) You defined mu as being mu= [Xcg - XAPT; YAPT - Ycg; Zcg - ZAPT] Why is only the Y component "backwards"? I thought the moment should be something like rCG=[Xcg ; Ycg ; Zcg]: reng=[Xeng ; Yeng ; Zeng]; r = reng - rCG M = cross (r , Fe) just like at 1:20:08
I am so grateful to watch such educative videos, many thanks, i have a question, we talk always about derivative of stability, if we take pitch moment as an example, it depends on Va, alpha, alpha dot, q and elevator deflection, however during your presentation Alpha dot effecte is not considered, is there any raison ? Or just it is a simplified pitch moment computation? Thanks a lot
Hi, Thanks for reaching out, I'm glad you enjoyed the video. Unfortunately I'm unable to respond to questions on RUclips due to the sheer volume of inquiries that I receive. That being said, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum as I'll be able to answer questions there. Given your interest in the topic, I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching! -Chris
Erik, yes, that is how this model is setup. It does seem a bit low but keep in mind that how the AoA is defined varies from aircraft to aircraft so perhaps the RCAM model just uses a different reference line to measure AoA.
Thanks for reaching out. If you have questions or would like to request a video, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
Hello sir, thanks alot for this video, it is really helpful. I need to develop a working model of a B747 on matlab, so can I follow these steps to accomplish the task ? Also, how can I find the saturation control limits of the aircraft ? Thank you
In case it is helpful, here are all the Flight Mechanics videos in a single playlist ruclips.net/p/PLxdnSsBqCrrEx3A6W94sQGClk6Q4YCg-h. You can support this channel via Patreon at www.patreon.com/christopherwlum. Please let me know what you think in the comments. Thanks for watching!
Thank you Prof. Lum. It is nice to have your videos of talking about the flight mechanics. For the nonlinear 6 DOF dynamic model, I expected something about the term ω ⃗×H ⃗, where H ⃗=(I_x p,I_y q,I_z r) which will cause nonlinear pitch instability as shown in my video: ruclips.net/video/gG2-mu6I11A/видео.html. I believe this nonlnear pitch instability is the root cause for two recent 737 Max crashes. You can also found my presentation about this claim at Slide 13 in www.aiaahouston.org/Horizons/ATS2019-Presentation-SS-Tang.pdf. I appreciate your thought about this phenomenon. Steve Tang
4 years of aeronautical engineering and nobody taught me how to do that...while you just did it in less than two hours. Thanks, professor!
Your aero degree made you watch this kid.
AE512: Love to see all the physics of a simplified aircraft in one video!
And that RCAM paper is pretty cool.
Great comprehensive overview of what became a critical part of the last 1/3 of the class.
AE 512: Very cool to see all the different expressions we've developed in the last few weeks finally used to simulate the aircraft dynamics. Great video!
Perfect. Thank you for the video. You deserve at least a million subscribers. And finally the Matlab simulation is coming :)
Yes, the Matlab sim video is coming this week. If you are subscribed hopefully you'll be notified when it goes live.
AA516: I referred to this video A LOT throughout the quarter. This was very helpful in troubleshooting my own RCAM model
AE512: Thanks for breaking down the dynamics equations for the RCAM model! This should help as we look at the aircraft response to inputs in Simulink.
Glad it was helpful!
AA516: These brewed up equations will be interesting to see implemented and visualized in simulink. Thanks Professor.
AE512: this video in particular was very helpful in understanding where the major simplifications are in the RCAM model.
As a Mechanical Engineer trying to implement Active Stability control, this is amazing!
I'm glad it was helpful. There are several related videos on the channel. Please feel free to check them out and I would love to hear what you think in the comments. Thanks for watching!
AE 512: great video prof. Lum. Looking forwards to the simulink part of this.
AA516: Thank you for this great video! I'm looking forward to building and implementing the model in simulink.
thanks for helping me get better at Kerbal Space Program
AA516: Looking forward to applying this in Simulink!
AE512: Thanks Chris for explaining the dynamics model of the RCAM aircraft. If only the aircraft we work on were this simple
Haha, I know, it would be great if we could simple models like this 😀. That being said, it is interesting to see what type of behavior is actually captured in this somewhat simplified model. We should talk on the other side about it, there are some things you might find interesting...
Such great work, as always....thank you.
AE512: I'm looking forward to implementing the RCAM model!
AA516 - I really enjoyed these RCAM videos. I had come across them for a couple years and always thought they looked cool. They are a large part of the reason I wanted to take this class. I added a basic 2D autopilot to mine, but want to use PID controllers to make a fly-by-wire system.
AE512: This is really cool. I'm honestly surprised how simple this can be.
AA516: I am looking forward to seeing the Simulink implementation! Even before implementing, it helps me to think of this in terms of the blocks diagrams
Great Video, great one stop refresher for us in industry
Hi Thomas, I'm glad it was helpful. There are other similar videos on the channel, please feel free to check them out and let me know what you think in the comments. Thanks for watching and I hope to catch you at another video.
AE512: It’s starting to seem fun to begin our simulation from this lecture
AE512: Great video, thanks!
AE512: Great lecture, especially when we combine all the hard work into a state vector (i.e a system we can simulate via simulink). Spoiler for the next video!
AA516: Very useful video, good pace
AA516: Very nice functional decomposition.
AA516: Excited to see the Matlab/Simulink implementation
Jason-AE512: Thanks professor. I understand much better by combining code and hand writing equations.
Thanks a Lot , i am really new in modelling complex system and this video can give me a hint
Hi Christopher, thanks a lot for that very detailed and understandable explanation of the model! But at one point I got a little confused about the values used. At 25:25 alpha_L0 is defined as negative 11.5*pi/180 but later at 38:45 you used positive 11.5*pi/180 as alpha_L0 which actually matches the value which I found in the RCAM publication. I am thankful for any further explanation!
Hi Markus, thanks for catching that. I believe the correct value is -11.5*pi/180 so I made a mistake/typo at 38:45. I believe the RCAM document lists -11.5*pi/180 as the proper value. Out of curiosity, where did you find the RCAM publication? Can you send me the URL or link to the location of where you obtained the document.
@@ChristopherLum Alright, the negative value is much more sensible though. Here (garteur.org/wp-content/reports/FM/FM_AG-08_TP-088-3.pdf) I found a report on the RCAM model on the Garteur website where it says alpha_L0 is the positive value, but what confuses me is that the publication is from 1995 instead of 1997 but it has exactly the same title and the rest also seems pretty much the same.
@@dimitris.159 Markus, thanks for the link. It looks like the 1995 version has the typo/mistake that we are discussing. It was fixed in the 1997 version.
I think there is a typo in dCMdx matrix, in the element 22, cbar should be squared (1:05:04). Great video, thank you!
AA516: This is really exciting - I can't wait to get into building the flight simulator!
I know, it is great to finally capitalize on all the previous background knowledge to actually build something. I'm excited to see what you do for your final project!
so,great teacher,so great tutorial!
I'm glad it was helpful. There are similar videos at ruclips.net/p/PLxdnSsBqCrrEx3A6W94sQGClk6Q4YCg-h. Please feel free to check them out and let me know what you think, thanks for watching!
I think I noticed a "typo" at 1:15:02. You used q (pitch rate), but I think you meant to use Q (aerodynamic pressure)
Justin, yes, great catch! This indeed is supposed to be dynamic pressure.
Really good video. Thanks Christopher
Such a fascinating lecture ! I can not find the 1997 document , I only have the 1995 which is a bit different , can you please post it ?
did you get this document
Have you got it? I need it too!
I have a challenge for you.
This model assumed that the airplane was flying in still air. Air is rarely still, it has updrafts, downdrafts and wind. I'd love to see how you add wind to the 6 DOF model. I have some ideas of my own, but I'd like to see how you would do it.
Thanks !
AA 516: Really cool to see all the content from previous lecture come together in the RCAM model! Regarding the equation we derived for the AoA of the tail, I did not quite understand the reasoning behind why one of the terms was proportional to the pitch rate and horizontal distance to the tail. This discussion was at the 41:30 mark.
Miles, good question. This is simply how they chose to model the dynamic pitch dampening effect of the tail. This is attempting to add behavior which makes it difficult to pitch the vehicle at a high rate. When q is large this creates a large AoA of the tail which in turn actually creates a negative pitching moment which counteracts the pitch rate. You could get a similar effect by adding this to the moment equation but for whatever reason, they chose to model it here. Let me know if you want to chat more about this at office hours.
You are an angel!
I'm glad it was helpful. There are several related videos on the channel. Please feel free to check them out and I would love to hear what you think in the comments. Thanks for watching!
Hi Christopher, thanks for your wonderful videos. I have been looking for the document (GARTEUR TP-0883) On the web page, but I cant found it. please if you have a link where I can found it, let me know
greetings from Ecuador
garteur.org/wp-content/reports/FM/FM_AG-08_TP-088-3.pdf
Here you go.
May I know where is the link to the "The Flat Earth Equations of Motion for a Rigid Body" video as mentioned in 0:11? I have been searching all the videos on your channel but still can't find it.
the same question asked again and again but still no answer from chriss. help me with the link incase u found it please
Great video!! Can you re-upload the missing videos please?? Thank you very much :)
That's what I was waiting for
I'm glad it was helpful. There are other similar videos on the channel please feel free to check them out and let me know what you think in the comments. Thanks for watching!
Hi. Thank you for making this detailed lecture series. I have a question. When rolling through 180 deg, the roll plot typically does "weird" stuff. What I observe is that say it is a positive roll, around 180 degree it suddenly drops to the negative side and continues increasing. Why do we observe this behavior. It also makes the pitch result very unbelievable. How does one interpret the data?
AA516: In industry, do engineers typically start with something like this simplified model and add onto it? Or is it too hard to complicate an existing model such that it's better to start complex and end complex?
May I know where can I get the RCAM report (preferably the latest one) you are referencing throughout the lecture?
Thank You
Hi, professor.I can't find the report in the internet.Can you tell me where to download it? Thank you very much!
AA516: Allie S, Im excited to apply this in Simulink and mess around with it to describe other aircraft
Hello dear teacher I am following your lessons Could you upload the video lesson 'the flat earth equations of motion for a Rigid body 'you mentioned at the beginning? Healthy Days...
AE 512: I'm curious how the stability/body typos you point out in the 1997 paper would affect implementing the model, my sense is under cruising conditions it won't do much but on takeoff/landing it could cause some real screwy behavior.
You're probably right. In many circumstances the stability and body axes are similar but in off nominal cases it could affect the system significantly.
Great video!!But I can’t find the wind tunnel video. Can you re-upload the missing videos please?? Thank you very much :)
Dear Lum and audiences: I cannot get access to the 1997 ver. document but only 1995 ver. on the website. Is there anyone can post a 1997ver. link or send me the relevant document. Lots of thanks @Christopher Lum
first i would like to present my gratitude for ur very helpfull lectures i have ever seen. next i would like u to give me the link for 2 videos;
1. "The Flat Earth Equations of Motion for a Rigid Body"
2. "Equations of motion for a planar vehicle"
Hey - lovely videos! thanks for these. A question - at 1:36:31, you reference flat earth equations. which video would that be? thanks again!
Many thanks！！！ KEEP GOING!!
AA 516: Will be interesting to see these utilized in the hw
Hi,
Dr. Christopher Lum
I hope you are fine.
I enjoy the tutorials you post on your RUclips channel and I thank you.
I am very interested in studying the field of tilt-rotor drones. But I didn't get a proper understanding of these types of drones through the articles. Can you help me to understand the model of this type of drones? Can you provide me with an instructional video or a resource that explains the modeling of these drones in detail?
thank you.
Hi,
Thanks for reaching out. If you have questions or would like to request a video, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum or via the 'Thanks' button underneath the video. I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
-Chris
AE 512: Coming back from the next video, at 1:03:37 I believe there is a typo on the board for dCM/dx, it should have cbar^2 in the denominator of the middle term.
AA516: I might have missed it and I can check the RCAM doc later. Was it specified which engine # corresponds to which side?
If you have your model working, you can simply test it. Apply asymmetric throttle settings and see which way the aircraft yaws.
[AE 512] 1:23:47
Why is the throttle put in terms of degrees? Shouldn't it be in terms of percentage. I am having trouble visualizing a throttle setting in degrees or radians?
As usual with this channel, wonderful explanation once again. It is indeed amazing that the complex 6 DOF model is explained in such an easy to understand language. Thank you Dr. Lum for creating such content. I have a small query here at approx 01:22:27. The moments automatically are represented in body frame. However, what if 6 DOF simulation model is prepared in wind-frame? Does moments need to be transferred from body to wind frame? Once again, thank you for creating the Flight mechanics channel.
Hi,
Thanks for reaching out, I'm glad you enjoyed the video. Unfortunately I'm unable to respond to questions on RUclips due to the sheer volume of inquiries that I receive. That being said, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum as I'll be able to answer questions there. Given your interest in the topic, I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
-Chris
@@ChristopherLum Thank you for your response, Dr. Lum. I will surely become your patron when I become a professor in the Aerospace department in a couple of years.
Is it possible to do this for any aircraft? I’m looking to do a dynamic model for the Cirrus SR22 but without documentation as easily available (from what I’ve seen) such as that you referenced from the Aeronautical Research, is it feasible?
1:05:32 Isn't Pitching Moment about aerodynamic center independent of alpha? Or is that in a different frame?
^The Aerodynamic center is the point at which the pitching moment coefficient for the airfoil does not vary with lift coefficient (i.e. angle of attack) en.wikipedia.org/wiki/Aerodynamic_center.
Which frame is the wiki article referring to?
amazing ！
I'm glad it was helpful. There are other similar videos on the channel. Please feel free to check them out and let me know what you think. Thanks for watching!
you are a superstar
I'm glad it was helpful, thanks for watching!
AE 512: I thought the moment transfer would be M + (r x F) rather than M + (F x r). Could you explain why you had M + (F x r)?
Hi Sunny, your timing is perfect, we were just talking about this at office hours an hour ago. Once this gets published please check it out and let me know if this makes sense.
@@ChristopherLum Hi Chris, I am not sure I am seeing the video you are referencing. Where should I be looking for it? I can't see a cloud recording on Canvas and unfortunately, I could not make office hours last night.
Sir your video is amazing. But sir I want to know where are wind tunnel testing and data reduction video lecture?
Exactly I am also looking for the same.
Thank you very much, I'm looking for 1997 document version and I can't find it; could you please send me the link for it?
Have you got it? I need it too!
AA516 - Hello Professor Lum, I noticed in the following video where we build the RCAM model in MATLAB, you have a squared term for the cbar variable in the dCMdx formula at 1:07:44 . In this video however, you don't have the squared term. Is this a typo?
When in double, go with the notes, it is likely I missed something when writing it on the board. Did you check against the RCAM document? Can you tell me which one appears to have the error?
@@ChristopherLum Yes, the RCAM document shows the cbar variable squared on page 17, so the error would be in this video not having the squared cbar for dCMdx. Thanks for the response!
@@icevarnaguleswaran7138 Great, thanks for cross checking. I'm glad we got this worked out.
Should the mu in the engine moment equation about the CG be (r_APTi - r_CG) instead of (r_CG - r_APTi) (at 1:30:00, not sure why the y element in mu is different either)? The value for ZAPTi probably should be positive instead of negative. The combination of these two errors save the day and generates acceptable final results.
EDIT: NVM, I saw that the table 2.4 is NOT at the body frame.
Original:
At around 1:30:37 you said that the moment due to the engine is
cross (mu , Fe)
You defined mu as being
mu= [Xcg - XAPT;
YAPT - Ycg;
Zcg - ZAPT]
Why is only the Y component "backwards"?
I thought the moment should be something like
rCG=[Xcg ; Ycg ; Zcg]:
reng=[Xeng ; Yeng ; Zeng];
r = reng - rCG
M = cross (r , Fe)
just like at 1:20:08
Sounds like it got sorted out. Thanks for watching!
Thanks a lot!
I am so grateful to watch such educative videos, many thanks, i have a question, we talk always about derivative of stability, if we take pitch moment as an example, it depends on Va, alpha, alpha dot, q and elevator deflection, however during your presentation Alpha dot effecte is not considered, is there any raison ? Or just it is a simplified pitch moment computation?
Thanks a lot
Hi,
Thanks for reaching out, I'm glad you enjoyed the video. Unfortunately I'm unable to respond to questions on RUclips due to the sheer volume of inquiries that I receive. That being said, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum as I'll be able to answer questions there. Given your interest in the topic, I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
-Chris
Thank you, I graduated 25 years ago, you make me feel so much younger! is there any possibility to get the slx file directly?
Thank you so much! Also is the alpha_L=0 really -11.5 deg? The absolute value of that seems larger than I'd expect.
Erik, yes, that is how this model is setup. It does seem a bit low but keep in mind that how the AoA is defined varies from aircraft to aircraft so perhaps the RCAM model just uses a different reference line to measure AoA.
Great work. Very useful lectures. I've a doubt how to find alpha coefficients a0, a1, a2 and a3? Thanks
Thanks for reaching out. If you have questions or would like to request a video, I hope you'll consider supporting the channel via Patreon at www.patreon.com/christopherwlum. I'd love to have you as a Patron as I'm able to talk/interact personally with Patrons. Thanks for watching!
Hello sir, thanks alot for this video, it is really helpful. I need to develop a working model of a B747 on matlab, so can I follow these steps to accomplish the task ? Also, how can I find the saturation control limits of the aircraft ?
Thank you
Your video came to me like rohirrims arriving at pelennor fields
can we attach bldc motors with this and check how the battery drains with how we fly in the simulink model?
I can’t find the wind tunnel video :(
Me neither :( did you find it in the end?
For trim condition i want to run my program how can i do it
Thank you!
sir where is the video of flat earth equations of motion?
I think you never uploaded that video.
@@bhaveshjoshi33 pls let me know if u have any idea where i can find this video. thanx
me neither can't find it...let me know the link incase u found it please.
I didn't find it
Hi, I would like to watch wind testing and flat earth equation video, but I can find it in your play list.
AA 516: Celeste Yuan
A A 516: realized I forgot to leave comments!
Don't worry, I've seen all your notifications and know that you're watching the videos. 10/10 for participation so far!