13 years on and this has just helped me massively for my POF exam ! Thankyou 😊
@MrGuily1
7 жыл бұрын
Thank you! So much easier to understand visually than from a textbook
@pejmanjavaheri9758
11 ай бұрын
Thank you so much for the excellent explanation of the relative airflow on a propeller. I have watched so many videos and I did not get my answer until now. Now, I understand the vectors and the resultant relative airflow for a rotating propeller. I can confidently say that no other video has explained how these vectors are derived.
@srisutharsan3089
6 жыл бұрын
Seriously you've done a great job explaining this, keep going
@b.o8144
4 жыл бұрын
Definitely the best explanation with proper visuals! Thank you Roddy
@tomizzo11
10 жыл бұрын
This is a great video. Very informational and cleared up several misconceptions I had regarding angle of attack vs blade angle. Keep up the great work!
@johnroberts7529
6 ай бұрын
What a beautifully paced and well structured video this is. Many thanks for all your hard work.
@gracehu4692
3 жыл бұрын
Thank you so much. I am working on CFI. I was trying to find this perfect explanation for a while. Finally I got it here. Good Job!
@WordofSpirit
3 жыл бұрын
this is what i was looking for. Now i can understand the other aspects of propeller blade bitting the air, blade and pitch. Thank you very much
@richardthuman3209
9 жыл бұрын
Roddy, thanks so much for this video. This is the first time that I actually understand how the different forces changes the Aoa
@RoddyMcNamee
12 жыл бұрын
Absolutely! The direction of the relative airflow should be pointing towards the propeller and not away from it!
@abdelazizmounji7798
11 ай бұрын
Cristal clear explanation. Thank you so much for putting this together
@st-rochguy4909
3 жыл бұрын
I ve been researching that for a whole week, thanks mate
@NikitaKaminskyy
2 жыл бұрын
Amazing explanation! Simple, clear and precise
@joaopedromuller7266
7 жыл бұрын
Dudee, thank you so much.. You have no idea how it got simple after i watch yur video...
@janicewong9622
7 жыл бұрын
Thank you so much you explained it so well with those clearly-illustrated diagrams
@BengalMailbyDeep
3 жыл бұрын
Thanks man...the way u explained made me understand everything in 4 mins..which I wasn't being able to do by going thru the book fr hours
@user-ey2jz2sh4s
9 ай бұрын
Thanks so much ! This help me to visualise AOA of propeller which is much more clear than those text books !
@doenja3319
3 жыл бұрын
Wow, ive been looking for a video like this for a while. Finally i understand this. thanks!!!
@Andreas20a
10 жыл бұрын
Sir, thank you very much, from you i understood how the propeller works.
@chandrashekhar-oq8io
5 жыл бұрын
Superb sir. Hats off to your explanation.. Thank u so much
@stvrstc
2 жыл бұрын
Best explanation I have ever seen, thanks so much....
@DetEJagDe
6 жыл бұрын
Cheers man! I didn't understand it at PPL theory, but thanks to you I do!
@lsx001
6 жыл бұрын
Thank you so much you explained it so well!
@jonnyball9375
7 жыл бұрын
Great, well explained. Good for PPL learning.
@RoddyMcNamee
11 жыл бұрын
Thanks for the feedback
@Elizabethlc26
8 жыл бұрын
YES. UGH YOURE BETTER THAN MY INSTRUCTOR. THANK U
@AeroMarko
7 жыл бұрын
It's just that the rotation in this case as you have shown is anticlockwise or left hand rotation. You have to look at the propeller from inside the cabin. Most of single engine pistons have clockwise rotation, so probably this propeller is also clockwise rotating, which would mean that it is rotating in the other than shown direction. Cheers mate
@invershin
13 жыл бұрын
Thank you so much!!! Finally I got it!!!
@funfacts5821
2 жыл бұрын
wow best explanation i was confused now its all clear thank you so much🙏🙏
@jeremyloyam7094
7 жыл бұрын
very well illustrated thanks man..
@pravinchavan643
6 жыл бұрын
Perfectly explanation!!!! Cheers
@DaudpotaArt
7 жыл бұрын
Awesome! Just what I was lloking for! Thanks sir! :-)
@abdullahmaruf7912
3 жыл бұрын
A very very clear presentation
@AlexanderMcAllister
8 жыл бұрын
Made perfect sense. Thank you.
@samnz502
11 жыл бұрын
A Short clip and so useful , Thank u very much :)
@saif8912
11 жыл бұрын
Omg thank you!! You literally saved my ass!!!
@user-js1lj3uz5t
6 жыл бұрын
Very clear explanation indeed
@anishkumarsingh1019
8 жыл бұрын
Very well explained.
@patteo8886
3 жыл бұрын
Thanks. It is very clear. Way to go!
@anandkelkar89
12 жыл бұрын
just to check, the relative air flow should be pointing opposite (as in pointing towards upper right corner)?
@mossmh3866
5 жыл бұрын
Great explanation thank you
@jonammp
4 жыл бұрын
Superb explanation.
@rustammaniiazov1208
2 жыл бұрын
very good explanation.
@040_shivangpatni_aero3
2 жыл бұрын
Well explained, thank you
@yoonjaekim8523
5 жыл бұрын
Thank you I couldn't learn this in my college
@RoddyMcNamee
11 жыл бұрын
You're welcome. Glad it was of some use.
@Kyoze0
9 жыл бұрын
thanks m8. thats very helpful
@am-pb4ci
4 жыл бұрын
Great video
@samythebull
7 жыл бұрын
easy to understand Thank you
@RoddyMcNamee
12 жыл бұрын
AviationMy, sorry for the tardy resonse, but I''Ve just seen your comment. For me, Blade Angle and Blade Pitch are the same thing.
@stevepegg2269
7 ай бұрын
yea...but air speed is determined thrust/clime/Descent relative to earth/gravity. So to increase air speed- either pinch change (less gravity) or increase in power
@ssunthra
11 жыл бұрын
Thank You...nice and simple...
@nicholasgenest352
4 жыл бұрын
Yes perfect explanation!!!
@samoo8933
2 жыл бұрын
I canot understand how the relative airflow is opposite to the propeller motion ? Should the realtive airflow comes from behind the falt side of blades not from the ground as your drawing them ?
@waynepetrevan
3 ай бұрын
For me the cross section of the blade looks wrong for a clockwise rotating prop and the airflow direction vectors you show. Maybe its just me......
@aviationMY
12 жыл бұрын
Hi I want to ask, in aircraft if blade angle increase what happened to the propeller blade pitch? (increase or decrease)
@pancake-de5iv
Ай бұрын
thanks, i was going to claw my eyes out playing flyout
@maierj-m2621
3 жыл бұрын
great job!
@fjficm
10 жыл бұрын
I'm not sure that this is correct. But I look at this from a wind turbine perspective but the principles are the same. Angle of attack (i) =Angle of incidence b/w relative wind and direction of motion of the plane (I) - Pitch angle (alpha). Given that the pitch angle remains the same an increase in I will increase the AoA. This is done via increasing wind speed or increasing plane velocity. Is this correct. Im unsure about propeller planes but can the pitch of the blades vary accordingly to optimise the AoA(i) so as to optimise Fd/Fl
@bikashburnwal2029
4 жыл бұрын
Elaborate what would be the effect when both acts at the same time sir...this video was really helpful, still there are some doubts
@elroydsouza7196
5 жыл бұрын
Amazing video Thanks. I had a doubt though , So the angle of attack at tip of the propeller would change because it moves at a higher angular velocity that the root of the , Blade correct? If not can someone clear this doubt for me ?
@RoddyMcNamee
5 жыл бұрын
No, the blade angle at the tip is smaller because the rotational velocity (V) is greater at the tip. The angular velocity ( omega) is the same all along the blade. The equation is: V = omega.radius At the tip the radius is at the maximum so the velocity is at the maximum.
@PilotBossify
3 ай бұрын
This one is great
@HossainSiddiqui
2 жыл бұрын
at the end, i think there is a typo error with "a decrease increase in AoA". Need to remove 'increase'. You have simplified a hard stuff.
@captainduffman1
10 жыл бұрын
great job ,thanks
@larryphotography
4 ай бұрын
This is the best video I found on the subject thank you! What really got me every time was that cross section diagram with the graphs. I had no clue what part of the propeller we're actually looking at. From what I can understand (and it would REALLY help to have an animation of an airplane going into the position of the graph before disappearing and leaving just that cross section) we are looking at the SIDE of the propeller as the plane is flying in from the right (and thus airspeed coming from the left). Is this correct? Thank you!
@RoddyMcNamee
4 ай бұрын
Yes, the cross section is of the propeller blade looking in from the side, with the aircraft flying from right to left.
@airmett8939
4 жыл бұрын
I don't understand why the propeller is always drawn pointing so far forward of the plane of rotation (such as at 1:46). Aren't the propeller blades flat with the plane of rotation?
@kevinoulahan9779
8 жыл бұрын
Why don't we have compact telescopic 3 tears propeller blades today for use in PAV's ( personal air vehicles) so that they can be extended in flight and retracted for driving on the ground ? For a real life all terrain vehicle?
@737silver
11 жыл бұрын
Thanks a lot. Bristol Atpl books are far away of fully understable explanation in principles of flight and other subjects :((
@yasiruilesinghe2611
5 жыл бұрын
what happens if the air speed is constant
@Jmaster009
5 жыл бұрын
BRILLIANT
@tintinfan007
4 жыл бұрын
Sir, can u tell me how this value of "vector due to rotational speed" is obtained ? is this actually the centrifugal force acting on the blades?
@RoddyMcNamee
4 жыл бұрын
No, it is the velocity vector due to the rotational speed. V= omega.r. where omega is the rotational speed in radians per second.
@tintinfan007
4 жыл бұрын
@@RoddyMcNamee oh u mean angular velocity ?
@djvinrapacitiez
11 жыл бұрын
very useful..thank you very much...more videos on gas turbine please:)
@RoddyMcNamee
12 жыл бұрын
Have a look at another screencast I made about blade asymmetric loading. If that doesn't help, come back to me.
@prathameshvichare8517
7 жыл бұрын
That relative wond component is wrong, please correct it. By the way the video is informative, Thankyou.
@animexd5083
2 жыл бұрын
How we have to Check the Direction of propeller rotation. Whether it is Clockwise or anti clockwise. From which position we have to check? I mean. by Standing infront of a/c or Sitting in pilot Seat?
@RoddyMcNamee
2 жыл бұрын
Standing behind the aircraft and looking forward.
@animexd5083
2 жыл бұрын
@@RoddyMcNamee thank you Sir!
@clipoff
3 жыл бұрын
Angle of Attack ??? what does it effect
@ramanpal1763
3 жыл бұрын
straight fire
@ericnelson4651
2 жыл бұрын
So the final question to tie this all together.. can a Fixed pitch propeller, operating normally (no malfunctions), engine operating normally to spin the prop, etc…..Can it stall?
@RoddyMcNamee
2 жыл бұрын
In flight, I would say the answer is no, it is very unlikely to stall.
@vikingpary
7 ай бұрын
Thank you
@ambition221
6 жыл бұрын
I did not understand the vertical speed. From where it comes from? 😔
@codyprice0295
5 жыл бұрын
Vertical speed is a result of higher propeller RPM that line is the measurement in force hitting the bottom of the airfoil. The lengths of the lines are 2d representation of the amount pressure exerting on the airfoil as the propeller moves faster or slower in that clockwise direction (vertical) or forward in airspeed (horizontal)
@brokozor
5 жыл бұрын
If the airspeed increases, this will cause a DECREASE INCREASE in angle of attack? Please DECREASE or INCREASE?
@RoddyMcNamee
5 жыл бұрын
All other things being equal (Blade angle, RPM), as airspeed increases, angle of attack will DECREASE.
@brokozor
5 жыл бұрын
Thank you Roddy, I was refering to last few seconds of the video, there is both decrease increase. Yup, speed up = angle of attack going down:) thanks for the video! Well made!
@ejanocrowsnatcher6785
4 жыл бұрын
When he says tree blade propeller and you think wow what a funny accent and then you remember that no wait tree is actually how you say it
@iruxcheri
Жыл бұрын
At 1:44 , the direction of relative airflow vector is incorrect. It should be opposite to what you have drawn. Great explanation though.
@RoddyMcNamee
Жыл бұрын
Yes, it is drawn incorrectly. I only noticed it after I’d posted and fully intended to remake the video. It’s now years later and I still ave great intentions of remaking it. 😀
@iruxcheri
Жыл бұрын
@@RoddyMcNamee Naah , it’s a great video. Why spend time on it when you can make one on a different topic for us :)
@gabrielsleiman69
10 жыл бұрын
If you increase the RPM therefore increasing the speed, how would it affect the AOA?
@RoddyMcNamee
10 жыл бұрын
How are you increasing RPM? Are you increasing the power to the engine, then there will be an increase in power delivered by the propeller, or are you increasing RPM by selecting a more fine blade angle?
@KingRichard920
10 жыл бұрын
*Assuming a fix pitched propeller for simplicity.* An increase in RPM does not necessarily assume an increase in airspeed. For example, slow flight relies upon pitch for airspeed and power for altitude.
@June-lf5hx
4 жыл бұрын
@@RoddyMcNamee Hi, i have the same question. why increase the RPM but the airspeed is the same? I didn't understand from your reply. Could you please explain more??
@omkarghase4653
9 жыл бұрын
nice one propeller blade ................i understand
@tintinfan007
4 жыл бұрын
I SUBSCRIBED
@07015678
9 жыл бұрын
Thanks Roddy. I presume this is for a fixed propeller?
@RoddyMcNamee
9 жыл бұрын
Yes, this was for a fixed pitch propeller but the principle can still be applied to a variable pitch prop.
@CapitanoGUC-gf6el
5 жыл бұрын
And what is the ideal angle of attack ?
@RoddyMcNamee
5 жыл бұрын
It depends on the prop, but usually the best lift / drag ratio of an airfoil occurs at about 4 degrees.
@eemtech1606
9 ай бұрын
If the airspeed increases, AoA decreases. How can we increase the airspeed?
@RoddyMcNamee
9 ай бұрын
Put the aircraft into a dive.
@eemtech1606
9 ай бұрын
@@RoddyMcNamee I see, make sense.
@RoddyMcNamee
11 жыл бұрын
You're welcome.
@chickenpineapple3213
5 жыл бұрын
Thanks
@MrAlwaysBlue
3 жыл бұрын
"Tree bladed propeller". I assume its a wooden one then?
@comctrevor864
2 жыл бұрын
Is there a video of solving the aoa?
@RoddyMcNamee
2 жыл бұрын
There are some videos called Propeller Analysis 1, 2 and 3. If they’re not helpful I’ll do one for you next week.
@comctrevor864
2 жыл бұрын
@@RoddyMcNamee you're the best!
@RoddyMcNamee
2 жыл бұрын
@@comctrevor864 have a look at this: kzitem.info/news/bejne/pJeMr4Kqo396pKQ is this what you were looking for?
@yanngumbs97133
2 жыл бұрын
GOD DAWM thanks finaly i understand !
@hsfhaz
3 жыл бұрын
So my textbook explain it right too but instead of talking about movement of airflow it use RPM and foward speed of the aircraft... Which is the incorrect way to explain the relative airflow.
@RoddyMcNamee
3 жыл бұрын
The relative airflow is the vector sum of forward speed and prop airflow due to RPM. So there is no difference in how they are being explained.
@RoddyMcNamee
11 жыл бұрын
Well I suppose on the bright side it wasn't BORRRRRING.
@karthikp2650
4 жыл бұрын
First you mention Greenarrow upside inclined. it satisfies vector addition triangle.second time you mentioned Green arrow downside inclined it didn't satifies vector addition. it confuse me. please explain .Thank you.
@RoddyMcNamee
4 жыл бұрын
The green vector (relative airflow) is pointing in the wrong direction. It should point upwards.
@williamcrisp7882
3 жыл бұрын
Roddy Mc Namee Thank you. I was confused about this part. Otherwise very good explanation!
@MagPencho
5 жыл бұрын
finally!
@chrisdrake4692
4 жыл бұрын
This is WRONG. Propellers SUCK AIR IN, as well as rotate, as well as are connected to a usually-moving thing, like an airplane. This video only considers the last two, and not the fact that the air is being sucked in in the first place. This was almost certainly left out deliberately - the shape of the blade and the angle of attack determines it's efficiency, which determines how much air it sucks in, which gets ugly. The angle-of-attack determines the airflow, AND the airflow determines the angle of attack - at some point an equilibrium is reached, which is highly non-trivial. You simply can't simplify this concept like Roddy did here.
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