![Roddy Mc Namee](/img/default-banner.jpg)
- 294
- 2 885 203
Roddy Mc Namee
Ireland
Registrace 12. 08. 2010
This channel is primarily to help describe some engineering principles.
Rotating Magnetic Field 2
This video reviews the rotating magnetic field and the mathematics that underpin it.
zhlédnutí: 550
Video
Resistive Starting of Single Phase Motor
zhlédnutí 937Před rokem
This video shows how a single phase motor can be started without a start capacitor.
Setback formula - Sheetmetal
zhlédnutí 4,3KPřed rokem
This video shows one particular method for calculating setback for sheetmetal applications.
Bend Allowance for Sheetmetal Applications
zhlédnutí 1,5KPřed rokem
This video shows how to calculate the bend allowance using the 2xpi method for sheetmetal applications.
Calculating Bend Allowance and Setback Example
zhlédnutí 49KPřed rokem
This example shows how to calculate the amount of metal required to manufacture a top-hat sheetmetal section using the 2xPi method.
Matching the aircraft, engine and propeller
zhlédnutí 2,9KPřed rokem
This video hopes to show the importance of matching the engine and propeller to the aircraft to achieve maximum efficiency. This is a re-recording as the original video had an error in it that just needed to be corrected.
Rotating Magnetic Field 2
zhlédnutí 974Před rokem
This is a belated update to a previous video on rotating magnetic fields. It shows the mathematical proof that the sum of 3 phases that are 120 degrees apart and 120 degrees out of phase is a rotating magnetic field.
Propeller Coefficient of Thrust
zhlédnutí 3,3KPřed rokem
This video looks at how a formula for a propeller coefficient of thrust was derived. It is almost completely based on a page from the MIT website. It's a lot longer than I wanted or planned, so apologies for that.
Calculating most efficient Propeller Blade Angle
zhlédnutí 8KPřed 2 lety
This video shows how the Blade Angle or Angle of Attack for a propeller can be determined from flight conditions if an efficiency is assumed./ Froude Momentum Therom czcams.com/video/hXmSxpGV4ps/video.html
Compressor Efficiency at altitude
zhlédnutí 3,4KPřed 2 lety
This video trys to explain why aircraft engines are more efficient at altitude. Gas Turbine engine efficiency is related to the compressor pressure ratio, and it is easier for compressors to work at altitude in the colder air.
Using a casio calculator for e functions 1
zhlédnutí 3,9KPřed 3 lety
This shows how to use the e function on a Casio Calculator
Minimum Power Required for a Prop Aircraft
zhlédnutí 3,5KPřed 3 lety
This video shows how to determine the minimum power required for a propeller aircraft. It goes though the derivation of a formula that provides the minimum power required for a piston engine aircraft. It is based on the assumption that at steady state, the thrust = drag and that the coefficient of drag Cd = Cd0 KCl^2. It therefore assumes that that designer knows the drag coefficient of the int...
Inlets 2 Types of inlets
zhlédnutí 3,1KPřed 3 lety
This video explains the different types of Engine Inlets.
Inlets 1 - Review of Bernoulli's Theorm
zhlédnutí 898Před 3 lety
This video reviews Bernoulli's theorm and applies it to the intake of Gas Turbine engines.
Gas Turbine Adiabatic Process Example 3
zhlédnutí 451Před 3 lety
Gas Turbine Adiabatic Process Example 3
Gas Turbine Adiabatic Process Example 2
zhlédnutí 378Před 3 lety
Gas Turbine Adiabatic Process Example 2
Gas Turbine Adiabatic Process Example 4
zhlédnutí 445Před 3 lety
Gas Turbine Adiabatic Process Example 4
Nozzles - Intuitive explanation of Critical Pressure
zhlédnutí 3,1KPřed 3 lety
Nozzles - Intuitive explanation of Critical Pressure
Derivation of Critical Pressure Quick Version
zhlédnutí 630Před 3 lety
Derivation of Critical Pressure Quick Version
Deflection of a cantilever beam with a Parabolic Load
zhlédnutí 2,2KPřed 3 lety
Deflection of a cantilever beam with a Parabolic Load
Determination of V0 from Froude Momentum Theory when only Power is provided.
zhlédnutí 900Před 3 lety
Determination of V0 from Froude Momentum Theory when only Power is provided.
Thank you sir ❤❤❤
Is this saying the Engine is "More Efficient" but develops "Less Power" (Thrust) ?
@@kletops46 Yes.
@@RoddyMcNamee Does that mean when ground based industrial units develop less power due to a decrease in barometric pressure, actually become slightly more efficient ?
@@kletops46 I never considered that before, but yes, if the compressor inlet pressure drops, then theoretically for a given compressor outlet the compression ratio will increase, leading to higher efficiency.
What will the angle of advance be with the aircraft stationary but propellers running?
@@gopikrishnanmenon5035 The angle of advance will be zero, which if you think about it makes sense as the aircraft won't have advanced.
My wife is Irish 🇮🇪🍀, thanks this video🥹.
Thank you!
great video....
Great content! What book do you recomend to read about this subject?
General Aviation Aircraft Design: Applied Methods and Procedures 2nd Edition by Snorri Gudmundsson (Author) - Chapter 15 has some good material on propellers.
Incredible video! 👏 Thank you. Im a visual learner.. i hate the fact that I can't visualize the concept. Its like I have no imagination..... But instantly clicks when I see it. Good grief. Taking my fire detection block test today.
👌👌👌👍
Super
When the apu is ready to provide electric power to the aircraft but the aircraft does not need electric power from the apu, is the apu disconnected from the apu generator to prevent the apu from providing electric power to the aircraft? I would like to know how electric power from the apu is regulated per the demand from the aircraft. Thank you.
If I wanted to optimize a propeller for static thrust, like the fan in a wind tunnel for example, would I then use the V0 value to calculate the resultant relative wind for setting the AOA of my blade elements?
Yes, that is what I would do.
Thank u ❤
It's not obvious to me that the point of max LD ratio is most efficient, do we not have to take induced drag into account in propellers?
THUMBS UP
Hello! Can the method on 4:48 be applied at 50% of the radius? or 25% of the radius?
@@user-zm6ej3uw3b yes, the same method applies.
Thank you. I have another question. Can there be a lift even though the propeller is rotating just by wind?
Great video. You explained it really nicely
Thanks. Was very helpful
13 years on and this has just helped me massively for my POF exam ! Thankyou 😊
Thank you!
Can you please reference the book you got this from
I don't think I got this from a book.
Good explanation, but you've got the magnet attractions backwards. Opposite poles attract, and like poles repel.
Please, can someone explain. If efficiency = 50% then a = 1 and V0=2V. If efficiency = 80% then a = 0.25 and V0=1,25V. Why air speed after propeller decrease while efficiency of propeller increase?
I spent a while looking for a good explanation of this. This is a great explanation! Thank you!
Hi, It was very good but sound is very low, please fix this issue thank you.
Thank you for explanation
Hands down, the best explanation of how an AC motor works! I'm a visual learner and that was clear as day!
❤❤❤❤❤very good
Edited: I wrote a comment here but I went through your second video and it's clear, you go for max thurst while I am interested in lift. Thank you.
What? North pole arracting north pole?
1:39 Can the flow speed go beyond Mach 1 just by using a converging nozzle?
Hard to find this information, thank you man, would be amazing if you could record again the audio
Hello Sir..Many thanks for this presentation... Appreciate your efforts.. I have a doubt.. At 2:05 , you have mentioned that the oil mist inside the bearing compartment cannot go past the labyrinth seal because of the low pressure inside the compartment caused by the pressurised airflow going inside through the labyrinth seal knife edges .... Is it technically okay to say that, "the oil mist cannot go outside through the labyrinth seal knife edges due to the continuous supply of pressurised air coming across the knife edges"... I'm taking the reference of the general property of a fluid where the flow of fluid in a particular direction is prevented in the presence of another opposing pressurised fluid flow...Can we omit that pressure differential phenomenon while explaining the oil sealing capability by only using the above mentioned property of fluid...Is it technically correct? Kindly pardon me for any mistake in my question. Thank you Sir!
@hari-rx3sh Yes you can say that "the oil mist cannot go outside through the labyrinth seal knife edges due to the continuous supply of pressurised air coming across the knife edges". The reason the air is flowing in that direction is because of the pressure differential..
@@RoddyMcNamee Many thanks for the explanation, Sir! Wish you the very best ahead.
thanks, i was going to claw my eyes out playing flyout
The day we start doing that on rocket engine turbines we can probably lift a skyscraper tall rocket.
sir your vise is not clear
Anybody watched young sheldon and watched this?
When use of air-cooled turbine blading began, General Electric favored film cooling whereas Pratt & Whitney favored convection & impingement cooling because they use less compressor bleed air, the turbine blades are simpler & cheaper to manufacture, there are no film cooling slots to clog, and the turbine efficiency penalty is lower because the blade cooling air is exhausted parallel to airflow.
Thank you sir🫡
Awesome video!
Very well explained. One point; the magnetic flux lines generated by phase 1 and phase 2 are separate fields and when you find the resultant, then it ends up with one magnitude and a direction that you showed. Additionally, if you increase or decrease the frequency you increase or decrease the speed (RPM) of the motor, and if you increase the number of pole pairs, you get the capacity the have more current draw and so resultantly produce higher torque. As I read on Quora; frequency is speed, current is torque, and voltage is the capacity to create torque.
Nice bro 👏 It was a detailed derivation
This one is great
Hello roddy thanks for information. Can we find thrust with this information?
You would need to know the aircraft velocity also to be able to calculate thrust.
@@RoddyMcNamee Thank you for your answer. Can you make a video for the thrust example? Or is there a link you can recommend? Thank you.
What is CD zero ? Is it the same as the CD value?
CD zero is the profile or parasitic drag. Drag can be considered as the sum of a number of contributing components, such as profile drag, induced drag etc etc. In this case the total coefficient of drag CD can be considered to equal = CDzero + "Induced Drag".
Well done! Timeless classic!
"North attract north, north repels south" I can't understand it
There is a North Pole and a North Seeking Pole. The North Seeking Pole is attracted to the North Pole. It's the same principle that has a North Seeking Pole on a compass, point towards the North Pole.
So, if you connect only one pair of winding to Line, and you spin shaft with hand, probably low torque could run when magnet got self internal power of spinning ? Thats interesting. Finally i understand why start winding with cap is needed
Very clear, many thanks!
great video, cleared up all my doubts. thanks