Rocket Engine Fundamentals and Design Part 2/2: Nozzle Expansion and Design Example
ฝัง
- เผยแพร่เมื่อ 1 มิ.ย. 2024
- This is part 2/2 of our series on rocket engine design and builds on the concepts of thrust and combustion covered in part 1. Feel free to comment with any questions and/or corrections pertaining to the content in the video. Hope you learn something new!
Topics:
0:00 - Intro
00:55 - Energy and Properties
10:16 - Ideal Gas Law and Flow Rates
16:39 - Isentropic Relations
21:51 - Mach Number
30:17 - Stagnation and Critical Conditions
43:11 - Choosing Propellants
50:21 - Constraining Thrust and Chamber Pressure
53:06 - Choosing Exit Pressure
55:42 - Choosing OF Ratio
1:01:11 - Manual Nozzle Sizing
1:16:08 - Manual Chamber Sizing
1:20:46 - Building the Engine in CAD
1:28:10 - Sizing the Engine in RPA
1:33:23 - Cooling
1:40:57 - Injectors
1:46:30 - Feed Systems
1:49:33 - Ignition
1:54:28 - Final Remarks
External Content:
Rocket Equation Sheet: drive.google.com/file/d/1AZXS...
Rocket Propulsion Elements (7th Edition) by George P. Sutton: mae-nas.eng.usu.edu/MAE_5540_W... - วิทยาศาสตร์และเทคโนโลยี
Thank you. I listened you like a student in a classroom
Amazing lecture and guidelines!! Thank you so much for taking your precious time to teach others. Please make more videos! maybe going in more depth about the topics of the end section other considerations".
😀
Rocket Club at Boise State owes you one. These videos are amazing, thank you very much!
This video is amazing, I was looking for something this in depth for ages and I never found it. Thank you for making this!
Thank you for the wonderful viedos. Those two parts videos are really informative.
Excellent ! Thank you.
Thank you for the video; it was informative and simple to understand.
9 inches chamber length = 22.86 cm. Just suggesting keeping everything in metric. Thank you for the best tutorial on rocket engines that I have ever seen.
thank u so much!
Thanks you..
Really great video! I was just wondering where do you implement any safety factors when designing your rocket engine? Cheers!
Great videos! Just a bit confused when u use index 0 as chamber position, as in the literature, 0 reference the stagnation properties. Would be nice to distinguish 0 with f.ex sub_c for chamber in the future (even if those are the same in this example) :)
Would suggest using metric instead of inches etc. So much simpler.
Great video. Do you know any other Chemical Equilibrium Softwares besides RPA and NASA CEA?
Thank you for the amazing video. May I have a question? What would it be different if one were designing a solid rocket motor in terms of the chamber? Would the chamber length L* be the size length of the propellant grain?
How May I Find k, R and T for a known propellant (HTPB/AP/Al for example)?
I thought that the walls are cooled with propellant, which means the heat tfansfers to the propellant and is put back onto the combistion chamber. Also, doesnt friction convert kinetic energy into heat, once again heating the walls, then heating the propellant, and then is injected back into the chamber?
Hello all
Why we calculate exit area by exit volume and not by a fixed expansion ratio number ?
For example I want my nozzle to have an expansion ratio of 14.
Isn't that a more logical approach and also how RPA works ?
1:06:43 unit are wrong. most be km/h instead of m/s for Mach 1. Meters per seocnd is 3600km/h wich is Mach 3.
Hi help pls , i am getting injector area in 1 micro m^2 ,too difficult to have that in real time, is my calculation correct?,
i am designing pintel injector for pressrue drop of 100 psi, fuel mass flow rate = 0.030 kg/s ,fuel density =800 kg/m3 ,Cd= 0.70 .
I am desiging engine for Thrust=294.3 N
Chamber pressure = 300psi
I am aiming to achieve throtability of 1 to 3
1:07:53 Why you say before lightweight molecole are better? Kinetic energy is mass*velocity right? more mass more energy come with and more velocity more energy expel. So why this dont apply to combustion rockets? For example the the CH4 and H2 fuels and LOX oxidizer. why H2 have more Isp? (must be something with the deflagration or detonation) but if both have lets see Mach3 ath exit nozzel the more thrust its given by the component with more weight wich is carbon 16;1 )
Nope, it's square of velocity. Ek = 1/2mv2 hence speed is more important than the mass
what you said about mass*velocity is momentum. energy, as stated in the comment above, is 1/2mv^2.
the reason why we want lighter molecules is because with lighter molecules it's easier to accelerate it to higher velocity. Also, rocket engine efficiency is measured by how fast the exhaust is going, so you want the highest exhaust velocity as possible.
hi sir, after using the calculations of the video, I keep ending up with a nozzle lesser than that of the throat, can you provide an explanation for this?
The equation that relates throat area to nozzle area involves a square root, so it should give you two answers. Perhaps you’re selecting the smaller of the two?
thank you very much for responding... The problem I had was that the nozzle equation(the mass flow rate= area*volume/velocity) outputted a lesser value than the throat area equation... I am converting these equations to solve for a, maybe I screwed up? (conversion= a=m/(volume/velocty))
People who are suggesting metric - please find one NASA document with metric.
This is probably a stupid question about fuel: compared to liquid methane and ethanol, how would methane dissolved in ethanol compare?
Like ethanol it's a liquid at room temperature and has a low boiling point meaning it can be gasified easily with a heat exchanger and you could potentially gain increased energy density from the methane.
The solubility of methane in ethanol is in the 0.01range at ambient temperature and pressure, so insignificant. You could get it up to the 0.3 range at hundreds of atmospheres of pressure, but then you would need to maintain that pressure through all its handling. pure.hw.ac.uk/ws/portalfiles/portal/9637950/Experimental_Measurement_and_Modeling_of_the_Solubility_of_Methane_in_Methanol_and_Ethanol.pdf#:~:text=The%20solubility%20of%20methane%20in%20methanol%20at%20273.15,K%20and%200.3%20to%2041.7%20MPa%20was%20measured.
Scientific talk and using psi. Like seriously?